Squashed 'tmk_core/' changes from 7967731..b9e0ea0
b9e0ea0 Merge commit '7fa9d8bdea3773d1195b04d98fcf27cf48ddd81d' as 'tool/mbed/mbed-sdk' 7fa9d8b Squashed 'tool/mbed/mbed-sdk/' content from commit 7c21ce5 git-subtree-dir: tmk_core git-subtree-split: b9e0ea08cb940de20b3610ecdda18e9d8cd7c552
This commit is contained in:
@ -0,0 +1,242 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_bitreversal.c
|
||||
*
|
||||
* Description: This file has common tables like Bitreverse, reciprocal etc which are used across different functions
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/*
|
||||
* @brief In-place bit reversal function.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
|
||||
* @param[in] fftSize length of the FFT.
|
||||
* @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table.
|
||||
* @param[in] *pBitRevTab points to the bit reversal table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_bitreversal_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftSize,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab)
|
||||
{
|
||||
uint16_t fftLenBy2, fftLenBy2p1;
|
||||
uint16_t i, j;
|
||||
float32_t in;
|
||||
|
||||
/* Initializations */
|
||||
j = 0u;
|
||||
fftLenBy2 = fftSize >> 1u;
|
||||
fftLenBy2p1 = (fftSize >> 1u) + 1u;
|
||||
|
||||
/* Bit Reversal Implementation */
|
||||
for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
|
||||
{
|
||||
if(i < j)
|
||||
{
|
||||
/* pSrc[i] <-> pSrc[j]; */
|
||||
in = pSrc[2u * i];
|
||||
pSrc[2u * i] = pSrc[2u * j];
|
||||
pSrc[2u * j] = in;
|
||||
|
||||
/* pSrc[i+1u] <-> pSrc[j+1u] */
|
||||
in = pSrc[(2u * i) + 1u];
|
||||
pSrc[(2u * i) + 1u] = pSrc[(2u * j) + 1u];
|
||||
pSrc[(2u * j) + 1u] = in;
|
||||
|
||||
/* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
|
||||
in = pSrc[2u * (i + fftLenBy2p1)];
|
||||
pSrc[2u * (i + fftLenBy2p1)] = pSrc[2u * (j + fftLenBy2p1)];
|
||||
pSrc[2u * (j + fftLenBy2p1)] = in;
|
||||
|
||||
/* pSrc[i+fftLenBy2p1+1u] <-> pSrc[j+fftLenBy2p1+1u] */
|
||||
in = pSrc[(2u * (i + fftLenBy2p1)) + 1u];
|
||||
pSrc[(2u * (i + fftLenBy2p1)) + 1u] =
|
||||
pSrc[(2u * (j + fftLenBy2p1)) + 1u];
|
||||
pSrc[(2u * (j + fftLenBy2p1)) + 1u] = in;
|
||||
|
||||
}
|
||||
|
||||
/* pSrc[i+1u] <-> pSrc[j+1u] */
|
||||
in = pSrc[2u * (i + 1u)];
|
||||
pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
|
||||
pSrc[2u * (j + fftLenBy2)] = in;
|
||||
|
||||
/* pSrc[i+2u] <-> pSrc[j+2u] */
|
||||
in = pSrc[(2u * (i + 1u)) + 1u];
|
||||
pSrc[(2u * (i + 1u)) + 1u] = pSrc[(2u * (j + fftLenBy2)) + 1u];
|
||||
pSrc[(2u * (j + fftLenBy2)) + 1u] = in;
|
||||
|
||||
/* Reading the index for the bit reversal */
|
||||
j = *pBitRevTab;
|
||||
|
||||
/* Updating the bit reversal index depending on the fft length */
|
||||
pBitRevTab += bitRevFactor;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
/*
|
||||
* @brief In-place bit reversal function.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
|
||||
* @param[in] *pBitRevTab points to bit reversal table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_bitreversal_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTable)
|
||||
{
|
||||
uint32_t fftLenBy2, fftLenBy2p1, i, j;
|
||||
q31_t in;
|
||||
|
||||
/* Initializations */
|
||||
j = 0u;
|
||||
fftLenBy2 = fftLen / 2u;
|
||||
fftLenBy2p1 = (fftLen / 2u) + 1u;
|
||||
|
||||
/* Bit Reversal Implementation */
|
||||
for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
|
||||
{
|
||||
if(i < j)
|
||||
{
|
||||
/* pSrc[i] <-> pSrc[j]; */
|
||||
in = pSrc[2u * i];
|
||||
pSrc[2u * i] = pSrc[2u * j];
|
||||
pSrc[2u * j] = in;
|
||||
|
||||
/* pSrc[i+1u] <-> pSrc[j+1u] */
|
||||
in = pSrc[(2u * i) + 1u];
|
||||
pSrc[(2u * i) + 1u] = pSrc[(2u * j) + 1u];
|
||||
pSrc[(2u * j) + 1u] = in;
|
||||
|
||||
/* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
|
||||
in = pSrc[2u * (i + fftLenBy2p1)];
|
||||
pSrc[2u * (i + fftLenBy2p1)] = pSrc[2u * (j + fftLenBy2p1)];
|
||||
pSrc[2u * (j + fftLenBy2p1)] = in;
|
||||
|
||||
/* pSrc[i+fftLenBy2p1+1u] <-> pSrc[j+fftLenBy2p1+1u] */
|
||||
in = pSrc[(2u * (i + fftLenBy2p1)) + 1u];
|
||||
pSrc[(2u * (i + fftLenBy2p1)) + 1u] =
|
||||
pSrc[(2u * (j + fftLenBy2p1)) + 1u];
|
||||
pSrc[(2u * (j + fftLenBy2p1)) + 1u] = in;
|
||||
|
||||
}
|
||||
|
||||
/* pSrc[i+1u] <-> pSrc[j+1u] */
|
||||
in = pSrc[2u * (i + 1u)];
|
||||
pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
|
||||
pSrc[2u * (j + fftLenBy2)] = in;
|
||||
|
||||
/* pSrc[i+2u] <-> pSrc[j+2u] */
|
||||
in = pSrc[(2u * (i + 1u)) + 1u];
|
||||
pSrc[(2u * (i + 1u)) + 1u] = pSrc[(2u * (j + fftLenBy2)) + 1u];
|
||||
pSrc[(2u * (j + fftLenBy2)) + 1u] = in;
|
||||
|
||||
/* Reading the index for the bit reversal */
|
||||
j = *pBitRevTable;
|
||||
|
||||
/* Updating the bit reversal index depending on the fft length */
|
||||
pBitRevTable += bitRevFactor;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
/*
|
||||
* @brief In-place bit reversal function.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of Q15 data type.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
|
||||
* @param[in] *pBitRevTab points to bit reversal table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_bitreversal_q15(
|
||||
q15_t * pSrc16,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab)
|
||||
{
|
||||
q31_t *pSrc = (q31_t *) pSrc16;
|
||||
q31_t in;
|
||||
uint32_t fftLenBy2, fftLenBy2p1;
|
||||
uint32_t i, j;
|
||||
|
||||
/* Initializations */
|
||||
j = 0u;
|
||||
fftLenBy2 = fftLen / 2u;
|
||||
fftLenBy2p1 = (fftLen / 2u) + 1u;
|
||||
|
||||
/* Bit Reversal Implementation */
|
||||
for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
|
||||
{
|
||||
if(i < j)
|
||||
{
|
||||
/* pSrc[i] <-> pSrc[j]; */
|
||||
/* pSrc[i+1u] <-> pSrc[j+1u] */
|
||||
in = pSrc[i];
|
||||
pSrc[i] = pSrc[j];
|
||||
pSrc[j] = in;
|
||||
|
||||
/* pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1]; */
|
||||
/* pSrc[i + fftLenBy2p1+1u] <-> pSrc[j + fftLenBy2p1+1u] */
|
||||
in = pSrc[i + fftLenBy2p1];
|
||||
pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1];
|
||||
pSrc[j + fftLenBy2p1] = in;
|
||||
}
|
||||
|
||||
/* pSrc[i+1u] <-> pSrc[j+fftLenBy2]; */
|
||||
/* pSrc[i+2] <-> pSrc[j+fftLenBy2+1u] */
|
||||
in = pSrc[i + 1u];
|
||||
pSrc[i + 1u] = pSrc[j + fftLenBy2];
|
||||
pSrc[j + fftLenBy2] = in;
|
||||
|
||||
/* Reading the index for the bit reversal */
|
||||
j = *pBitRevTab;
|
||||
|
||||
/* Updating the bit reversal index depending on the fft length */
|
||||
pBitRevTab += bitRevFactor;
|
||||
}
|
||||
}
|
@ -0,0 +1,148 @@
|
||||
;/* ----------------------------------------------------------------------
|
||||
;* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
;*
|
||||
;* $Date: 17. January 2013
|
||||
;* $Revision: V1.4.1
|
||||
;*
|
||||
;* Project: CMSIS DSP Library
|
||||
;* Title: arm_bitreversal2.S
|
||||
;*
|
||||
;* Description: This is the arm_bitreversal_32 function done in
|
||||
;* assembly for maximum speed. This function is called
|
||||
;* after doing an fft to reorder the output. The function
|
||||
;* is loop unrolled by 2.
|
||||
;*
|
||||
;* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
;*
|
||||
;* Redistribution and use in source and binary forms, with or without
|
||||
;* modification, are permitted provided that the following conditions
|
||||
;* are met:
|
||||
;* - Redistributions of source code must retain the above copyright
|
||||
;* notice, this list of conditions and the following disclaimer.
|
||||
;* - Redistributions in binary form must reproduce the above copyright
|
||||
;* notice, this list of conditions and the following disclaimer in
|
||||
;* the documentation and/or other materials provided with the
|
||||
;* distribution.
|
||||
;* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
;* may be used to endorse or promote products derived from this
|
||||
;* software without specific prior written permission.
|
||||
;*
|
||||
;* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
;* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
;* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
;* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
;* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
;* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
;* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
;* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
;* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
;* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
;* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
;* POSSIBILITY OF SUCH DAMAGE.
|
||||
;* -------------------------------------------------------------------- */
|
||||
#if defined(__CC_ARM) //Keil
|
||||
#define CODESECT AREA ||.text||, CODE, READONLY, ALIGN=2
|
||||
#define LABEL
|
||||
#elif defined(__IASMARM__) //IAR
|
||||
#define CODESECT SECTION `.text`:CODE
|
||||
#define PROC
|
||||
#define LABEL
|
||||
#define ENDP
|
||||
#define EXPORT PUBLIC
|
||||
#elif defined (__GNUC__) //GCC
|
||||
.syntax unified
|
||||
.cpu cortex-m4
|
||||
.fpu softvfp
|
||||
#define THUMB .thumb
|
||||
#define CODESECT .section text
|
||||
#define EXPORT .global
|
||||
#define PROC :
|
||||
#define LABEL :
|
||||
#define ENDP
|
||||
#define END
|
||||
#endif
|
||||
|
||||
CODESECT
|
||||
THUMB
|
||||
|
||||
;/*
|
||||
;* @brief In-place bit reversal function.
|
||||
;* @param[in, out] *pSrc points to the in-place buffer of unknown 32-bit data type.
|
||||
;* @param[in] bitRevLen bit reversal table length
|
||||
;* @param[in] *pBitRevTab points to bit reversal table.
|
||||
;* @return none.
|
||||
;*/
|
||||
EXPORT arm_bitreversal_32
|
||||
|
||||
#if defined(ARM_MATH_CM0) || defined(ARM_MATH_CM0PLUS)
|
||||
|
||||
arm_bitreversal_32 PROC
|
||||
ADDS r3,r1,#1
|
||||
PUSH {r4-r6}
|
||||
ADDS r1,r2,#0
|
||||
LSRS r3,r3,#1
|
||||
arm_bitreversal_32_0 LABEL
|
||||
LDRH r2,[r1,#2]
|
||||
LDRH r6,[r1,#0]
|
||||
ADD r2,r0,r2
|
||||
ADD r6,r0,r6
|
||||
LDR r5,[r2,#0]
|
||||
LDR r4,[r6,#0]
|
||||
STR r5,[r6,#0]
|
||||
STR r4,[r2,#0]
|
||||
LDR r5,[r2,#4]
|
||||
LDR r4,[r6,#4]
|
||||
STR r5,[r6,#4]
|
||||
STR r4,[r2,#4]
|
||||
ADDS r1,r1,#4
|
||||
SUBS r3,r3,#1
|
||||
BNE arm_bitreversal_32_0
|
||||
POP {r4-r6}
|
||||
BX lr
|
||||
ENDP
|
||||
|
||||
#else
|
||||
|
||||
arm_bitreversal_32 PROC
|
||||
ADDS r3,r1,#1
|
||||
CMP r3,#1
|
||||
IT LS
|
||||
BXLS lr
|
||||
PUSH {r4-r9}
|
||||
ADDS r1,r2,#2
|
||||
LSRS r3,r3,#2
|
||||
arm_bitreversal_32_0 LABEL ;/* loop unrolled by 2 */
|
||||
LDRH r8,[r1,#4]
|
||||
LDRH r9,[r1,#2]
|
||||
LDRH r2,[r1,#0]
|
||||
LDRH r12,[r1,#-2]
|
||||
ADD r8,r0,r8
|
||||
ADD r9,r0,r9
|
||||
ADD r2,r0,r2
|
||||
ADD r12,r0,r12
|
||||
LDR r7,[r9,#0]
|
||||
LDR r6,[r8,#0]
|
||||
LDR r5,[r2,#0]
|
||||
LDR r4,[r12,#0]
|
||||
STR r6,[r9,#0]
|
||||
STR r7,[r8,#0]
|
||||
STR r5,[r12,#0]
|
||||
STR r4,[r2,#0]
|
||||
LDR r7,[r9,#4]
|
||||
LDR r6,[r8,#4]
|
||||
LDR r5,[r2,#4]
|
||||
LDR r4,[r12,#4]
|
||||
STR r6,[r9,#4]
|
||||
STR r7,[r8,#4]
|
||||
STR r5,[r12,#4]
|
||||
STR r4,[r2,#4]
|
||||
ADDS r1,r1,#8
|
||||
SUBS r3,r3,#1
|
||||
BNE arm_bitreversal_32_0
|
||||
POP {r4-r9}
|
||||
BX lr
|
||||
ENDP
|
||||
|
||||
#endif
|
||||
|
||||
END
|
@ -0,0 +1,616 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_f32.c
|
||||
*
|
||||
* Description: Combined Radix Decimation in Frequency CFFT Floating point processing function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
extern void arm_radix8_butterfly_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftLen,
|
||||
const float32_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
extern void arm_bitreversal_32(
|
||||
uint32_t * pSrc,
|
||||
const uint16_t bitRevLen,
|
||||
const uint16_t * pBitRevTable);
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @defgroup ComplexFFT Complex FFT Functions
|
||||
*
|
||||
* \par
|
||||
* The Fast Fourier Transform (FFT) is an efficient algorithm for computing the
|
||||
* Discrete Fourier Transform (DFT). The FFT can be orders of magnitude faster
|
||||
* than the DFT, especially for long lengths.
|
||||
* The algorithms described in this section
|
||||
* operate on complex data. A separate set of functions is devoted to handling
|
||||
* of real sequences.
|
||||
* \par
|
||||
* There are separate algorithms for handling floating-point, Q15, and Q31 data
|
||||
* types. The algorithms available for each data type are described next.
|
||||
* \par
|
||||
* The FFT functions operate in-place. That is, the array holding the input data
|
||||
* will also be used to hold the corresponding result. The input data is complex
|
||||
* and contains <code>2*fftLen</code> interleaved values as shown below.
|
||||
* <pre> {real[0], imag[0], real[1], imag[1],..} </pre>
|
||||
* The FFT result will be contained in the same array and the frequency domain
|
||||
* values will have the same interleaving.
|
||||
*
|
||||
* \par Floating-point
|
||||
* The floating-point complex FFT uses a mixed-radix algorithm. Multiple radix-8
|
||||
* stages are performed along with a single radix-2 or radix-4 stage, as needed.
|
||||
* The algorithm supports lengths of [16, 32, 64, ..., 4096] and each length uses
|
||||
* a different twiddle factor table.
|
||||
* \par
|
||||
* The function uses the standard FFT definition and output values may grow by a
|
||||
* factor of <code>fftLen</code> when computing the forward transform. The
|
||||
* inverse transform includes a scale of <code>1/fftLen</code> as part of the
|
||||
* calculation and this matches the textbook definition of the inverse FFT.
|
||||
* \par
|
||||
* Preinitialized data structures containing twiddle factors and bit reversal
|
||||
* tables are provided and defined in <code>arm_const_structs.h</code>. Include
|
||||
* this header in your function and then pass one of the constant structures as
|
||||
* an argument to arm_cfft_f32. For example:
|
||||
* \par
|
||||
* <code>arm_cfft_f32(arm_cfft_sR_f32_len64, pSrc, 1, 1)</code>
|
||||
* \par
|
||||
* computes a 64-point inverse complex FFT including bit reversal.
|
||||
* The data structures are treated as constant data and not modified during the
|
||||
* calculation. The same data structure can be reused for multiple transforms
|
||||
* including mixing forward and inverse transforms.
|
||||
* \par
|
||||
* Earlier releases of the library provided separate radix-2 and radix-4
|
||||
* algorithms that operated on floating-point data. These functions are still
|
||||
* provided but are deprecated. The older functions are slower and less general
|
||||
* than the new functions.
|
||||
* \par
|
||||
* An example of initialization of the constants for the arm_cfft_f32 function follows:
|
||||
* \par
|
||||
* const static arm_cfft_instance_f32 *S;
|
||||
* ...
|
||||
* switch (length) {
|
||||
* case 16:
|
||||
* S = & arm_cfft_sR_f32_len16;
|
||||
* break;
|
||||
* case 32:
|
||||
* S = & arm_cfft_sR_f32_len32;
|
||||
* break;
|
||||
* case 64:
|
||||
* S = & arm_cfft_sR_f32_len64;
|
||||
* break;
|
||||
* case 128:
|
||||
* S = & arm_cfft_sR_f32_len128;
|
||||
* break;
|
||||
* case 256:
|
||||
* S = & arm_cfft_sR_f32_len256;
|
||||
* break;
|
||||
* case 512:
|
||||
* S = & arm_cfft_sR_f32_len512;
|
||||
* break;
|
||||
* case 1024:
|
||||
* S = & arm_cfft_sR_f32_len1024;
|
||||
* break;
|
||||
* case 2048:
|
||||
* S = & arm_cfft_sR_f32_len2048;
|
||||
* break;
|
||||
* case 4096:
|
||||
* S = & arm_cfft_sR_f32_len4096;
|
||||
* break;
|
||||
* }
|
||||
* \par Q15 and Q31
|
||||
* The library provides radix-2 and radix-4 FFT algorithms for fixed-point data. The
|
||||
* radix-2 algorithm supports lengths of [16, 32, 64, ..., 4096]. The radix-4
|
||||
* algorithm supports lengths of [16, 64, 256, ..., 4096]. When possible, you
|
||||
* should use the radix-4 algorithm since it is faster than the radix-2 of the
|
||||
* same length.
|
||||
* \par
|
||||
* The forward FFTs include scaling in order to prevent results from overflowing.
|
||||
* Intermediate results are scaled down during each butterfly stage. In the
|
||||
* radix-2 algorithm, a scale of 0.5 is applied during each butterfly. In the
|
||||
* radix-4 algorithm, a scale of 0.25 is applied. The scaling applies to both
|
||||
* the forward and the inverse FFTs. Thus the forward FFT contains an additional
|
||||
* scale factor of <code>1/fftLen</code> as compared to the standard textbook
|
||||
* definition of the FFT. The inverse FFT also scales down during each butterfly
|
||||
* stage and this corresponds to the standard textbook definition.
|
||||
* \par
|
||||
* A separate instance structure must be defined for each transform used but
|
||||
* twiddle factor and bit reversal tables can be reused.
|
||||
* \par
|
||||
* There is also an associated initialization function for each data type.
|
||||
* The initialization function performs the following operations:
|
||||
* - Sets the values of the internal structure fields.
|
||||
* - Initializes twiddle factor table and bit reversal table pointers.
|
||||
* \par
|
||||
* Use of the initialization function is optional.
|
||||
* However, if the initialization function is used, then the instance structure
|
||||
* cannot be placed into a const data section. To place an instance structure
|
||||
* into a const data section, the instance structure should be manually
|
||||
* initialized as follows:
|
||||
* <pre>
|
||||
*arm_cfft_radix2_instance_q31 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor};
|
||||
*arm_cfft_radix2_instance_q15 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor};
|
||||
*arm_cfft_radix4_instance_q31 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor};
|
||||
*arm_cfft_radix4_instance_q15 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor};
|
||||
*arm_cfft_instance_f32 S = {fftLen, pTwiddle, pBitRevTable, bitRevLength};
|
||||
* </pre>
|
||||
* \par
|
||||
* where <code>fftLen</code> length of CFFT/CIFFT; <code>ifftFlag</code> Flag for
|
||||
* selection of forward or inverse transform. When ifftFlag is set the inverse
|
||||
* transform is calculated.
|
||||
* <code>bitReverseFlag</code> Flag for selection of output order (Set bitReverseFlag to output in normal order otherwise output in bit reversed order);
|
||||
* <code>pTwiddle</code>points to array of twiddle coefficients; <code>pBitRevTable</code> points to the bit reversal table.
|
||||
* <code>twidCoefModifier</code> modifier for twiddle factor table which supports all FFT lengths with same table;
|
||||
* <code>pBitRevTable</code> modifier for bit reversal table which supports all FFT lengths with same table.
|
||||
* <code>onebyfftLen</code> value of 1/fftLen to calculate CIFFT;
|
||||
* \par
|
||||
* The Q15 and Q31 FFT functions use a large bit reversal and twiddle factor
|
||||
* table. The tables are defined for the maximum length transform and a subset
|
||||
* of the coefficients are used in shorter transforms.
|
||||
*
|
||||
*/
|
||||
|
||||
void arm_cfft_radix8by2_f32( arm_cfft_instance_f32 * S, float32_t * p1)
|
||||
{
|
||||
uint32_t L = S->fftLen;
|
||||
float32_t * pCol1, * pCol2, * pMid1, * pMid2;
|
||||
float32_t * p2 = p1 + L;
|
||||
const float32_t * tw = (float32_t *) S->pTwiddle;
|
||||
float32_t t1[4], t2[4], t3[4], t4[4], twR, twI;
|
||||
float32_t m0, m1, m2, m3;
|
||||
uint32_t l;
|
||||
|
||||
pCol1 = p1;
|
||||
pCol2 = p2;
|
||||
|
||||
// Define new length
|
||||
L >>= 1;
|
||||
// Initialize mid pointers
|
||||
pMid1 = p1 + L;
|
||||
pMid2 = p2 + L;
|
||||
|
||||
// do two dot Fourier transform
|
||||
for ( l = L >> 2; l > 0; l-- )
|
||||
{
|
||||
t1[0] = p1[0];
|
||||
t1[1] = p1[1];
|
||||
t1[2] = p1[2];
|
||||
t1[3] = p1[3];
|
||||
|
||||
t2[0] = p2[0];
|
||||
t2[1] = p2[1];
|
||||
t2[2] = p2[2];
|
||||
t2[3] = p2[3];
|
||||
|
||||
t3[0] = pMid1[0];
|
||||
t3[1] = pMid1[1];
|
||||
t3[2] = pMid1[2];
|
||||
t3[3] = pMid1[3];
|
||||
|
||||
t4[0] = pMid2[0];
|
||||
t4[1] = pMid2[1];
|
||||
t4[2] = pMid2[2];
|
||||
t4[3] = pMid2[3];
|
||||
|
||||
*p1++ = t1[0] + t2[0];
|
||||
*p1++ = t1[1] + t2[1];
|
||||
*p1++ = t1[2] + t2[2];
|
||||
*p1++ = t1[3] + t2[3]; // col 1
|
||||
|
||||
t2[0] = t1[0] - t2[0];
|
||||
t2[1] = t1[1] - t2[1];
|
||||
t2[2] = t1[2] - t2[2];
|
||||
t2[3] = t1[3] - t2[3]; // for col 2
|
||||
|
||||
*pMid1++ = t3[0] + t4[0];
|
||||
*pMid1++ = t3[1] + t4[1];
|
||||
*pMid1++ = t3[2] + t4[2];
|
||||
*pMid1++ = t3[3] + t4[3]; // col 1
|
||||
|
||||
t4[0] = t4[0] - t3[0];
|
||||
t4[1] = t4[1] - t3[1];
|
||||
t4[2] = t4[2] - t3[2];
|
||||
t4[3] = t4[3] - t3[3]; // for col 2
|
||||
|
||||
twR = *tw++;
|
||||
twI = *tw++;
|
||||
|
||||
// multiply by twiddle factors
|
||||
m0 = t2[0] * twR;
|
||||
m1 = t2[1] * twI;
|
||||
m2 = t2[1] * twR;
|
||||
m3 = t2[0] * twI;
|
||||
|
||||
// R = R * Tr - I * Ti
|
||||
*p2++ = m0 + m1;
|
||||
// I = I * Tr + R * Ti
|
||||
*p2++ = m2 - m3;
|
||||
|
||||
// use vertical symmetry
|
||||
// 0.9988 - 0.0491i <==> -0.0491 - 0.9988i
|
||||
m0 = t4[0] * twI;
|
||||
m1 = t4[1] * twR;
|
||||
m2 = t4[1] * twI;
|
||||
m3 = t4[0] * twR;
|
||||
|
||||
*pMid2++ = m0 - m1;
|
||||
*pMid2++ = m2 + m3;
|
||||
|
||||
twR = *tw++;
|
||||
twI = *tw++;
|
||||
|
||||
m0 = t2[2] * twR;
|
||||
m1 = t2[3] * twI;
|
||||
m2 = t2[3] * twR;
|
||||
m3 = t2[2] * twI;
|
||||
|
||||
*p2++ = m0 + m1;
|
||||
*p2++ = m2 - m3;
|
||||
|
||||
m0 = t4[2] * twI;
|
||||
m1 = t4[3] * twR;
|
||||
m2 = t4[3] * twI;
|
||||
m3 = t4[2] * twR;
|
||||
|
||||
*pMid2++ = m0 - m1;
|
||||
*pMid2++ = m2 + m3;
|
||||
}
|
||||
|
||||
// first col
|
||||
arm_radix8_butterfly_f32( pCol1, L, (float32_t *) S->pTwiddle, 2u);
|
||||
// second col
|
||||
arm_radix8_butterfly_f32( pCol2, L, (float32_t *) S->pTwiddle, 2u);
|
||||
|
||||
}
|
||||
|
||||
void arm_cfft_radix8by4_f32( arm_cfft_instance_f32 * S, float32_t * p1)
|
||||
{
|
||||
uint32_t L = S->fftLen >> 1;
|
||||
float32_t * pCol1, *pCol2, *pCol3, *pCol4, *pEnd1, *pEnd2, *pEnd3, *pEnd4;
|
||||
const float32_t *tw2, *tw3, *tw4;
|
||||
float32_t * p2 = p1 + L;
|
||||
float32_t * p3 = p2 + L;
|
||||
float32_t * p4 = p3 + L;
|
||||
float32_t t2[4], t3[4], t4[4], twR, twI;
|
||||
float32_t p1ap3_0, p1sp3_0, p1ap3_1, p1sp3_1;
|
||||
float32_t m0, m1, m2, m3;
|
||||
uint32_t l, twMod2, twMod3, twMod4;
|
||||
|
||||
pCol1 = p1; // points to real values by default
|
||||
pCol2 = p2;
|
||||
pCol3 = p3;
|
||||
pCol4 = p4;
|
||||
pEnd1 = p2 - 1; // points to imaginary values by default
|
||||
pEnd2 = p3 - 1;
|
||||
pEnd3 = p4 - 1;
|
||||
pEnd4 = pEnd3 + L;
|
||||
|
||||
tw2 = tw3 = tw4 = (float32_t *) S->pTwiddle;
|
||||
|
||||
L >>= 1;
|
||||
|
||||
// do four dot Fourier transform
|
||||
|
||||
twMod2 = 2;
|
||||
twMod3 = 4;
|
||||
twMod4 = 6;
|
||||
|
||||
// TOP
|
||||
p1ap3_0 = p1[0] + p3[0];
|
||||
p1sp3_0 = p1[0] - p3[0];
|
||||
p1ap3_1 = p1[1] + p3[1];
|
||||
p1sp3_1 = p1[1] - p3[1];
|
||||
|
||||
// col 2
|
||||
t2[0] = p1sp3_0 + p2[1] - p4[1];
|
||||
t2[1] = p1sp3_1 - p2[0] + p4[0];
|
||||
// col 3
|
||||
t3[0] = p1ap3_0 - p2[0] - p4[0];
|
||||
t3[1] = p1ap3_1 - p2[1] - p4[1];
|
||||
// col 4
|
||||
t4[0] = p1sp3_0 - p2[1] + p4[1];
|
||||
t4[1] = p1sp3_1 + p2[0] - p4[0];
|
||||
// col 1
|
||||
*p1++ = p1ap3_0 + p2[0] + p4[0];
|
||||
*p1++ = p1ap3_1 + p2[1] + p4[1];
|
||||
|
||||
// Twiddle factors are ones
|
||||
*p2++ = t2[0];
|
||||
*p2++ = t2[1];
|
||||
*p3++ = t3[0];
|
||||
*p3++ = t3[1];
|
||||
*p4++ = t4[0];
|
||||
*p4++ = t4[1];
|
||||
|
||||
tw2 += twMod2;
|
||||
tw3 += twMod3;
|
||||
tw4 += twMod4;
|
||||
|
||||
for (l = (L - 2) >> 1; l > 0; l-- )
|
||||
{
|
||||
|
||||
// TOP
|
||||
p1ap3_0 = p1[0] + p3[0];
|
||||
p1sp3_0 = p1[0] - p3[0];
|
||||
p1ap3_1 = p1[1] + p3[1];
|
||||
p1sp3_1 = p1[1] - p3[1];
|
||||
// col 2
|
||||
t2[0] = p1sp3_0 + p2[1] - p4[1];
|
||||
t2[1] = p1sp3_1 - p2[0] + p4[0];
|
||||
// col 3
|
||||
t3[0] = p1ap3_0 - p2[0] - p4[0];
|
||||
t3[1] = p1ap3_1 - p2[1] - p4[1];
|
||||
// col 4
|
||||
t4[0] = p1sp3_0 - p2[1] + p4[1];
|
||||
t4[1] = p1sp3_1 + p2[0] - p4[0];
|
||||
// col 1 - top
|
||||
*p1++ = p1ap3_0 + p2[0] + p4[0];
|
||||
*p1++ = p1ap3_1 + p2[1] + p4[1];
|
||||
|
||||
// BOTTOM
|
||||
p1ap3_1 = pEnd1[-1] + pEnd3[-1];
|
||||
p1sp3_1 = pEnd1[-1] - pEnd3[-1];
|
||||
p1ap3_0 = pEnd1[0] + pEnd3[0];
|
||||
p1sp3_0 = pEnd1[0] - pEnd3[0];
|
||||
// col 2
|
||||
t2[2] = pEnd2[0] - pEnd4[0] + p1sp3_1;
|
||||
t2[3] = pEnd1[0] - pEnd3[0] - pEnd2[-1] + pEnd4[-1];
|
||||
// col 3
|
||||
t3[2] = p1ap3_1 - pEnd2[-1] - pEnd4[-1];
|
||||
t3[3] = p1ap3_0 - pEnd2[0] - pEnd4[0];
|
||||
// col 4
|
||||
t4[2] = pEnd2[0] - pEnd4[0] - p1sp3_1;
|
||||
t4[3] = pEnd4[-1] - pEnd2[-1] - p1sp3_0;
|
||||
// col 1 - Bottom
|
||||
*pEnd1-- = p1ap3_0 + pEnd2[0] + pEnd4[0];
|
||||
*pEnd1-- = p1ap3_1 + pEnd2[-1] + pEnd4[-1];
|
||||
|
||||
// COL 2
|
||||
// read twiddle factors
|
||||
twR = *tw2++;
|
||||
twI = *tw2++;
|
||||
// multiply by twiddle factors
|
||||
// let Z1 = a + i(b), Z2 = c + i(d)
|
||||
// => Z1 * Z2 = (a*c - b*d) + i(b*c + a*d)
|
||||
// Top
|
||||
m0 = t2[0] * twR;
|
||||
m1 = t2[1] * twI;
|
||||
m2 = t2[1] * twR;
|
||||
m3 = t2[0] * twI;
|
||||
|
||||
*p2++ = m0 + m1;
|
||||
*p2++ = m2 - m3;
|
||||
// use vertical symmetry col 2
|
||||
// 0.9997 - 0.0245i <==> 0.0245 - 0.9997i
|
||||
// Bottom
|
||||
m0 = t2[3] * twI;
|
||||
m1 = t2[2] * twR;
|
||||
m2 = t2[2] * twI;
|
||||
m3 = t2[3] * twR;
|
||||
|
||||
*pEnd2-- = m0 - m1;
|
||||
*pEnd2-- = m2 + m3;
|
||||
|
||||
// COL 3
|
||||
twR = tw3[0];
|
||||
twI = tw3[1];
|
||||
tw3 += twMod3;
|
||||
// Top
|
||||
m0 = t3[0] * twR;
|
||||
m1 = t3[1] * twI;
|
||||
m2 = t3[1] * twR;
|
||||
m3 = t3[0] * twI;
|
||||
|
||||
*p3++ = m0 + m1;
|
||||
*p3++ = m2 - m3;
|
||||
// use vertical symmetry col 3
|
||||
// 0.9988 - 0.0491i <==> -0.9988 - 0.0491i
|
||||
// Bottom
|
||||
m0 = -t3[3] * twR;
|
||||
m1 = t3[2] * twI;
|
||||
m2 = t3[2] * twR;
|
||||
m3 = t3[3] * twI;
|
||||
|
||||
*pEnd3-- = m0 - m1;
|
||||
*pEnd3-- = m3 - m2;
|
||||
|
||||
// COL 4
|
||||
twR = tw4[0];
|
||||
twI = tw4[1];
|
||||
tw4 += twMod4;
|
||||
// Top
|
||||
m0 = t4[0] * twR;
|
||||
m1 = t4[1] * twI;
|
||||
m2 = t4[1] * twR;
|
||||
m3 = t4[0] * twI;
|
||||
|
||||
*p4++ = m0 + m1;
|
||||
*p4++ = m2 - m3;
|
||||
// use vertical symmetry col 4
|
||||
// 0.9973 - 0.0736i <==> -0.0736 + 0.9973i
|
||||
// Bottom
|
||||
m0 = t4[3] * twI;
|
||||
m1 = t4[2] * twR;
|
||||
m2 = t4[2] * twI;
|
||||
m3 = t4[3] * twR;
|
||||
|
||||
*pEnd4-- = m0 - m1;
|
||||
*pEnd4-- = m2 + m3;
|
||||
}
|
||||
|
||||
//MIDDLE
|
||||
// Twiddle factors are
|
||||
// 1.0000 0.7071-0.7071i -1.0000i -0.7071-0.7071i
|
||||
p1ap3_0 = p1[0] + p3[0];
|
||||
p1sp3_0 = p1[0] - p3[0];
|
||||
p1ap3_1 = p1[1] + p3[1];
|
||||
p1sp3_1 = p1[1] - p3[1];
|
||||
|
||||
// col 2
|
||||
t2[0] = p1sp3_0 + p2[1] - p4[1];
|
||||
t2[1] = p1sp3_1 - p2[0] + p4[0];
|
||||
// col 3
|
||||
t3[0] = p1ap3_0 - p2[0] - p4[0];
|
||||
t3[1] = p1ap3_1 - p2[1] - p4[1];
|
||||
// col 4
|
||||
t4[0] = p1sp3_0 - p2[1] + p4[1];
|
||||
t4[1] = p1sp3_1 + p2[0] - p4[0];
|
||||
// col 1 - Top
|
||||
*p1++ = p1ap3_0 + p2[0] + p4[0];
|
||||
*p1++ = p1ap3_1 + p2[1] + p4[1];
|
||||
|
||||
// COL 2
|
||||
twR = tw2[0];
|
||||
twI = tw2[1];
|
||||
|
||||
m0 = t2[0] * twR;
|
||||
m1 = t2[1] * twI;
|
||||
m2 = t2[1] * twR;
|
||||
m3 = t2[0] * twI;
|
||||
|
||||
*p2++ = m0 + m1;
|
||||
*p2++ = m2 - m3;
|
||||
// COL 3
|
||||
twR = tw3[0];
|
||||
twI = tw3[1];
|
||||
|
||||
m0 = t3[0] * twR;
|
||||
m1 = t3[1] * twI;
|
||||
m2 = t3[1] * twR;
|
||||
m3 = t3[0] * twI;
|
||||
|
||||
*p3++ = m0 + m1;
|
||||
*p3++ = m2 - m3;
|
||||
// COL 4
|
||||
twR = tw4[0];
|
||||
twI = tw4[1];
|
||||
|
||||
m0 = t4[0] * twR;
|
||||
m1 = t4[1] * twI;
|
||||
m2 = t4[1] * twR;
|
||||
m3 = t4[0] * twI;
|
||||
|
||||
*p4++ = m0 + m1;
|
||||
*p4++ = m2 - m3;
|
||||
|
||||
// first col
|
||||
arm_radix8_butterfly_f32( pCol1, L, (float32_t *) S->pTwiddle, 4u);
|
||||
// second col
|
||||
arm_radix8_butterfly_f32( pCol2, L, (float32_t *) S->pTwiddle, 4u);
|
||||
// third col
|
||||
arm_radix8_butterfly_f32( pCol3, L, (float32_t *) S->pTwiddle, 4u);
|
||||
// fourth col
|
||||
arm_radix8_butterfly_f32( pCol4, L, (float32_t *) S->pTwiddle, 4u);
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @details
|
||||
* @brief Processing function for the floating-point complex FFT.
|
||||
* @param[in] *S points to an instance of the floating-point CFFT structure.
|
||||
* @param[in, out] *p1 points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_cfft_f32(
|
||||
const arm_cfft_instance_f32 * S,
|
||||
float32_t * p1,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
|
||||
uint32_t L = S->fftLen, l;
|
||||
float32_t invL, * pSrc;
|
||||
|
||||
if(ifftFlag == 1u)
|
||||
{
|
||||
/* Conjugate input data */
|
||||
pSrc = p1 + 1;
|
||||
for(l=0; l<L; l++) {
|
||||
*pSrc = -*pSrc;
|
||||
pSrc += 2;
|
||||
}
|
||||
}
|
||||
|
||||
switch (L) {
|
||||
case 16:
|
||||
case 128:
|
||||
case 1024:
|
||||
arm_cfft_radix8by2_f32 ( (arm_cfft_instance_f32 *) S, p1);
|
||||
break;
|
||||
case 32:
|
||||
case 256:
|
||||
case 2048:
|
||||
arm_cfft_radix8by4_f32 ( (arm_cfft_instance_f32 *) S, p1);
|
||||
break;
|
||||
case 64:
|
||||
case 512:
|
||||
case 4096:
|
||||
arm_radix8_butterfly_f32( p1, L, (float32_t *) S->pTwiddle, 1);
|
||||
break;
|
||||
}
|
||||
|
||||
if( bitReverseFlag )
|
||||
arm_bitreversal_32((uint32_t*)p1,S->bitRevLength,S->pBitRevTable);
|
||||
|
||||
if(ifftFlag == 1u)
|
||||
{
|
||||
invL = 1.0f/(float32_t)L;
|
||||
/* Conjugate and scale output data */
|
||||
pSrc = p1;
|
||||
for(l=0; l<L; l++) {
|
||||
*pSrc++ *= invL ;
|
||||
*pSrc = -(*pSrc) * invL;
|
||||
pSrc++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
@ -0,0 +1,485 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix2_f32.c
|
||||
*
|
||||
* Description: Radix-2 Decimation in Frequency CFFT & CIFFT Floating point processing function
|
||||
*
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void arm_radix2_butterfly_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
void arm_radix2_butterfly_inverse_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pCoef,
|
||||
uint16_t twidCoefModifier,
|
||||
float32_t onebyfftLen);
|
||||
|
||||
extern void arm_bitreversal_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftSize,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @details
|
||||
* @brief Radix-2 CFFT/CIFFT.
|
||||
* @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f32 and will be removed
|
||||
* in the future.
|
||||
* @param[in] *S points to an instance of the floating-point Radix-2 CFFT/CIFFT structure.
|
||||
* @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_cfft_radix2_f32(
|
||||
const arm_cfft_radix2_instance_f32 * S,
|
||||
float32_t * pSrc)
|
||||
{
|
||||
|
||||
if(S->ifftFlag == 1u)
|
||||
{
|
||||
/* Complex IFFT radix-2 */
|
||||
arm_radix2_butterfly_inverse_f32(pSrc, S->fftLen, S->pTwiddle,
|
||||
S->twidCoefModifier, S->onebyfftLen);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Complex FFT radix-2 */
|
||||
arm_radix2_butterfly_f32(pSrc, S->fftLen, S->pTwiddle,
|
||||
S->twidCoefModifier);
|
||||
}
|
||||
|
||||
if(S->bitReverseFlag == 1u)
|
||||
{
|
||||
/* Bit Reversal */
|
||||
arm_bitreversal_f32(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
||||
|
||||
|
||||
|
||||
/* ----------------------------------------------------------------------
|
||||
** Internal helper function used by the FFTs
|
||||
** ------------------------------------------------------------------- */
|
||||
|
||||
/*
|
||||
* @brief Core function for the floating-point CFFT butterfly process.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] *pCoef points to the twiddle coefficient buffer.
|
||||
* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_radix2_butterfly_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pCoef,
|
||||
uint16_t twidCoefModifier)
|
||||
{
|
||||
|
||||
uint32_t i, j, k, l;
|
||||
uint32_t n1, n2, ia;
|
||||
float32_t xt, yt, cosVal, sinVal;
|
||||
float32_t p0, p1, p2, p3;
|
||||
float32_t a0, a1;
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* Initializations for the first stage */
|
||||
n2 = fftLen >> 1;
|
||||
ia = 0;
|
||||
i = 0;
|
||||
|
||||
// loop for groups
|
||||
for (k = n2; k > 0; k--)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
|
||||
/* Twiddle coefficients index modifier */
|
||||
ia += twidCoefModifier;
|
||||
|
||||
/* index calculation for the input as, */
|
||||
/* pSrc[i + 0], pSrc[i + fftLen/1] */
|
||||
l = i + n2;
|
||||
|
||||
/* Butterfly implementation */
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
|
||||
p0 = xt * cosVal;
|
||||
p1 = yt * sinVal;
|
||||
p2 = yt * cosVal;
|
||||
p3 = xt * sinVal;
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
|
||||
pSrc[2 * l] = p0 + p1;
|
||||
pSrc[2 * l + 1] = p2 - p3;
|
||||
|
||||
i++;
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier <<= 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = n2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
j = 0;
|
||||
do
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia += twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i = j;
|
||||
do
|
||||
{
|
||||
l = i + n2;
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
|
||||
p0 = xt * cosVal;
|
||||
p1 = yt * sinVal;
|
||||
p2 = yt * cosVal;
|
||||
p3 = xt * sinVal;
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
|
||||
pSrc[2 * l] = p0 + p1;
|
||||
pSrc[2 * l + 1] = p2 - p3;
|
||||
|
||||
i += n1;
|
||||
} while( i < fftLen ); // butterfly loop end
|
||||
j++;
|
||||
} while( j < n2); // groups loop end
|
||||
twidCoefModifier <<= 1u;
|
||||
} // stages loop end
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += 2)
|
||||
{
|
||||
a0 = pSrc[2 * i] + pSrc[2 * i + 2];
|
||||
xt = pSrc[2 * i] - pSrc[2 * i + 2];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * i + 3];
|
||||
a1 = pSrc[2 * i + 3] + pSrc[2 * i + 1];
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
pSrc[2 * i + 2] = xt;
|
||||
pSrc[2 * i + 3] = yt;
|
||||
} // groups loop end
|
||||
|
||||
#else
|
||||
|
||||
n2 = fftLen;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen; k > 1; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
j = 0;
|
||||
do
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia += twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i = j;
|
||||
do
|
||||
{
|
||||
l = i + n2;
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
|
||||
p0 = xt * cosVal;
|
||||
p1 = yt * sinVal;
|
||||
p2 = yt * cosVal;
|
||||
p3 = xt * sinVal;
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
|
||||
pSrc[2 * l] = p0 + p1;
|
||||
pSrc[2 * l + 1] = p2 - p3;
|
||||
|
||||
i += n1;
|
||||
} while(i < fftLen);
|
||||
j++;
|
||||
} while(j < n2);
|
||||
twidCoefModifier <<= 1u;
|
||||
}
|
||||
|
||||
#endif // #ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
}
|
||||
|
||||
|
||||
void arm_radix2_butterfly_inverse_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pCoef,
|
||||
uint16_t twidCoefModifier,
|
||||
float32_t onebyfftLen)
|
||||
{
|
||||
|
||||
uint32_t i, j, k, l;
|
||||
uint32_t n1, n2, ia;
|
||||
float32_t xt, yt, cosVal, sinVal;
|
||||
float32_t p0, p1, p2, p3;
|
||||
float32_t a0, a1;
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
n2 = fftLen >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (i = 0; i < n2; i++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia += twidCoefModifier;
|
||||
|
||||
l = i + n2;
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
|
||||
p0 = xt * cosVal;
|
||||
p1 = yt * sinVal;
|
||||
p2 = yt * cosVal;
|
||||
p3 = xt * sinVal;
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
|
||||
pSrc[2 * l] = p0 - p1;
|
||||
pSrc[2 * l + 1] = p2 + p3;
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier <<= 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
j = 0;
|
||||
do
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia += twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i = j;
|
||||
do
|
||||
{
|
||||
l = i + n2;
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
|
||||
p0 = xt * cosVal;
|
||||
p1 = yt * sinVal;
|
||||
p2 = yt * cosVal;
|
||||
p3 = xt * sinVal;
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
|
||||
pSrc[2 * l] = p0 - p1;
|
||||
pSrc[2 * l + 1] = p2 + p3;
|
||||
|
||||
i += n1;
|
||||
} while( i < fftLen ); // butterfly loop end
|
||||
j++;
|
||||
} while(j < n2); // groups loop end
|
||||
|
||||
twidCoefModifier <<= 1u;
|
||||
} // stages loop end
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += 2)
|
||||
{
|
||||
a0 = pSrc[2 * i] + pSrc[2 * i + 2];
|
||||
xt = pSrc[2 * i] - pSrc[2 * i + 2];
|
||||
|
||||
a1 = pSrc[2 * i + 3] + pSrc[2 * i + 1];
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * i + 3];
|
||||
|
||||
p0 = a0 * onebyfftLen;
|
||||
p2 = xt * onebyfftLen;
|
||||
p1 = a1 * onebyfftLen;
|
||||
p3 = yt * onebyfftLen;
|
||||
|
||||
pSrc[2 * i] = p0;
|
||||
pSrc[2 * i + 1] = p1;
|
||||
pSrc[2 * i + 2] = p2;
|
||||
pSrc[2 * i + 3] = p3;
|
||||
} // butterfly loop end
|
||||
|
||||
#else
|
||||
|
||||
n2 = fftLen;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
j = 0;
|
||||
do
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i = j;
|
||||
do
|
||||
{
|
||||
l = i + n2;
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
|
||||
p0 = xt * cosVal;
|
||||
p1 = yt * sinVal;
|
||||
p2 = yt * cosVal;
|
||||
p3 = xt * sinVal;
|
||||
|
||||
pSrc[2 * i] = a0;
|
||||
pSrc[2 * i + 1] = a1;
|
||||
|
||||
pSrc[2 * l] = p0 - p1;
|
||||
pSrc[2 * l + 1] = p2 + p3;
|
||||
|
||||
i += n1;
|
||||
} while( i < fftLen ); // butterfly loop end
|
||||
j++;
|
||||
} while( j < n2 ); // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
|
||||
a0 = pSrc[2 * i] + pSrc[2 * l];
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
|
||||
a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1];
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
|
||||
p0 = a0 * onebyfftLen;
|
||||
p2 = xt * onebyfftLen;
|
||||
p1 = a1 * onebyfftLen;
|
||||
p3 = yt * onebyfftLen;
|
||||
|
||||
pSrc[2 * i] = p0;
|
||||
pSrc[2u * l] = p2;
|
||||
|
||||
pSrc[2 * i + 1] = p1;
|
||||
pSrc[2u * l + 1u] = p3;
|
||||
} // butterfly loop end
|
||||
|
||||
#endif // #ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
}
|
@ -0,0 +1,205 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix4_init_f32.c
|
||||
*
|
||||
* Description: Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT Initialization function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Initialization function for the floating-point CFFT/CIFFT.
|
||||
* @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f32 and will be removed
|
||||
* in the future.
|
||||
* @param[in,out] *S points to an instance of the floating-point CFFT/CIFFT structure.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
arm_status arm_cfft_radix2_init_f32(
|
||||
arm_cfft_radix2_instance_f32 * S,
|
||||
uint16_t fftLen,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
|
||||
/* Initialise the FFT length */
|
||||
S->fftLen = fftLen;
|
||||
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
S->pTwiddle = (float32_t *) twiddleCoef;
|
||||
|
||||
/* Initialise the Flag for selection of CFFT or CIFFT */
|
||||
S->ifftFlag = ifftFlag;
|
||||
|
||||
/* Initialise the Flag for calculation Bit reversal or not */
|
||||
S->bitReverseFlag = bitReverseFlag;
|
||||
|
||||
/* Initializations of structure parameters depending on the FFT length */
|
||||
switch (S->fftLen)
|
||||
{
|
||||
|
||||
case 4096u:
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 1u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 1u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) armBitRevTable;
|
||||
/* Initialise the 1/fftLen Value */
|
||||
S->onebyfftLen = 0.000244140625;
|
||||
break;
|
||||
|
||||
case 2048u:
|
||||
/* Initializations of structure parameters for 2048 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 2u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 2u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[1];
|
||||
/* Initialise the 1/fftLen Value */
|
||||
S->onebyfftLen = 0.00048828125;
|
||||
break;
|
||||
|
||||
case 1024u:
|
||||
/* Initializations of structure parameters for 1024 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 4u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 4u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
|
||||
/* Initialise the 1/fftLen Value */
|
||||
S->onebyfftLen = 0.0009765625f;
|
||||
break;
|
||||
|
||||
case 512u:
|
||||
/* Initializations of structure parameters for 512 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 8u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 8u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[7];
|
||||
/* Initialise the 1/fftLen Value */
|
||||
S->onebyfftLen = 0.001953125;
|
||||
break;
|
||||
|
||||
case 256u:
|
||||
/* Initializations of structure parameters for 256 point FFT */
|
||||
S->twidCoefModifier = 16u;
|
||||
S->bitRevFactor = 16u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
|
||||
S->onebyfftLen = 0.00390625f;
|
||||
break;
|
||||
|
||||
case 128u:
|
||||
/* Initializations of structure parameters for 128 point FFT */
|
||||
S->twidCoefModifier = 32u;
|
||||
S->bitRevFactor = 32u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[31];
|
||||
S->onebyfftLen = 0.0078125;
|
||||
break;
|
||||
|
||||
case 64u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 64u;
|
||||
S->bitRevFactor = 64u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
|
||||
S->onebyfftLen = 0.015625f;
|
||||
break;
|
||||
|
||||
case 32u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 128u;
|
||||
S->bitRevFactor = 128u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[127];
|
||||
S->onebyfftLen = 0.03125;
|
||||
break;
|
||||
|
||||
case 16u:
|
||||
/* Initializations of structure parameters for 16 point FFT */
|
||||
S->twidCoefModifier = 256u;
|
||||
S->bitRevFactor = 256u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
|
||||
S->onebyfftLen = 0.0625f;
|
||||
break;
|
||||
|
||||
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
@ -0,0 +1,188 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix2_init_q15.c
|
||||
*
|
||||
* Description: Radix-2 Decimation in Frequency Q15 FFT & IFFT initialization function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Initialization function for the Q15 CFFT/CIFFT.
|
||||
* @param[in,out] *S points to an instance of the Q15 CFFT/CIFFT structure.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
|
||||
arm_status arm_cfft_radix2_init_q15(
|
||||
arm_cfft_radix2_instance_q15 * S,
|
||||
uint16_t fftLen,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
|
||||
/* Initialise the FFT length */
|
||||
S->fftLen = fftLen;
|
||||
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
S->pTwiddle = (q15_t *) twiddleCoefQ15;
|
||||
/* Initialise the Flag for selection of CFFT or CIFFT */
|
||||
S->ifftFlag = ifftFlag;
|
||||
/* Initialise the Flag for calculation Bit reversal or not */
|
||||
S->bitReverseFlag = bitReverseFlag;
|
||||
|
||||
/* Initializations of structure parameters depending on the FFT length */
|
||||
switch (S->fftLen)
|
||||
{
|
||||
case 4096u:
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 1u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 1u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) armBitRevTable;
|
||||
|
||||
break;
|
||||
|
||||
case 2048u:
|
||||
/* Initializations of structure parameters for 2048 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 2u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 2u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[1];
|
||||
|
||||
break;
|
||||
|
||||
case 1024u:
|
||||
/* Initializations of structure parameters for 1024 point FFT */
|
||||
S->twidCoefModifier = 4u;
|
||||
S->bitRevFactor = 4u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
|
||||
|
||||
break;
|
||||
|
||||
case 512u:
|
||||
/* Initializations of structure parameters for 512 point FFT */
|
||||
S->twidCoefModifier = 8u;
|
||||
S->bitRevFactor = 8u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[7];
|
||||
|
||||
break;
|
||||
|
||||
case 256u:
|
||||
/* Initializations of structure parameters for 256 point FFT */
|
||||
S->twidCoefModifier = 16u;
|
||||
S->bitRevFactor = 16u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
|
||||
|
||||
break;
|
||||
|
||||
case 128u:
|
||||
/* Initializations of structure parameters for 128 point FFT */
|
||||
S->twidCoefModifier = 32u;
|
||||
S->bitRevFactor = 32u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[31];
|
||||
|
||||
break;
|
||||
|
||||
case 64u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 64u;
|
||||
S->bitRevFactor = 64u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
|
||||
|
||||
break;
|
||||
|
||||
case 32u:
|
||||
/* Initializations of structure parameters for 32 point FFT */
|
||||
S->twidCoefModifier = 128u;
|
||||
S->bitRevFactor = 128u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[127];
|
||||
|
||||
break;
|
||||
|
||||
case 16u:
|
||||
/* Initializations of structure parameters for 16 point FFT */
|
||||
S->twidCoefModifier = 256u;
|
||||
S->bitRevFactor = 256u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
|
||||
|
||||
break;
|
||||
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
@ -0,0 +1,186 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix2_init_q31.c
|
||||
*
|
||||
* Description: Radix-2 Decimation in Frequency Fixed-point CFFT & CIFFT Initialization function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
|
||||
/**
|
||||
*
|
||||
* @brief Initialization function for the Q31 CFFT/CIFFT.
|
||||
* @param[in,out] *S points to an instance of the Q31 CFFT/CIFFT structure.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
|
||||
arm_status arm_cfft_radix2_init_q31(
|
||||
arm_cfft_radix2_instance_q31 * S,
|
||||
uint16_t fftLen,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
|
||||
/* Initialise the FFT length */
|
||||
S->fftLen = fftLen;
|
||||
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
S->pTwiddle = (q31_t *) twiddleCoefQ31;
|
||||
/* Initialise the Flag for selection of CFFT or CIFFT */
|
||||
S->ifftFlag = ifftFlag;
|
||||
/* Initialise the Flag for calculation Bit reversal or not */
|
||||
S->bitReverseFlag = bitReverseFlag;
|
||||
|
||||
/* Initializations of Instance structure depending on the FFT length */
|
||||
switch (S->fftLen)
|
||||
{
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
case 4096u:
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 1u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 1u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) armBitRevTable;
|
||||
break;
|
||||
|
||||
/* Initializations of structure parameters for 2048 point FFT */
|
||||
case 2048u:
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 2u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 2u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[1];
|
||||
break;
|
||||
|
||||
/* Initializations of structure parameters for 1024 point FFT */
|
||||
case 1024u:
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 4u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 4u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
|
||||
break;
|
||||
|
||||
/* Initializations of structure parameters for 512 point FFT */
|
||||
case 512u:
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 8u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 8u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[7];
|
||||
break;
|
||||
|
||||
case 256u:
|
||||
/* Initializations of structure parameters for 256 point FFT */
|
||||
S->twidCoefModifier = 16u;
|
||||
S->bitRevFactor = 16u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
|
||||
break;
|
||||
|
||||
case 128u:
|
||||
/* Initializations of structure parameters for 128 point FFT */
|
||||
S->twidCoefModifier = 32u;
|
||||
S->bitRevFactor = 32u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[31];
|
||||
break;
|
||||
|
||||
case 64u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 64u;
|
||||
S->bitRevFactor = 64u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
|
||||
break;
|
||||
|
||||
case 32u:
|
||||
/* Initializations of structure parameters for 32 point FFT */
|
||||
S->twidCoefModifier = 128u;
|
||||
S->bitRevFactor = 128u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[127];
|
||||
break;
|
||||
|
||||
case 16u:
|
||||
/* Initializations of structure parameters for 16 point FFT */
|
||||
S->twidCoefModifier = 256u;
|
||||
S->bitRevFactor = 256u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
|
||||
break;
|
||||
|
||||
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
@ -0,0 +1,741 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix2_q15.c
|
||||
*
|
||||
* Description: Radix-2 Decimation in Frequency CFFT & CIFFT Fixed point processing function
|
||||
*
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void arm_radix2_butterfly_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
void arm_radix2_butterfly_inverse_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
void arm_bitreversal_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @details
|
||||
* @brief Processing function for the fixed-point CFFT/CIFFT.
|
||||
* @param[in] *S points to an instance of the fixed-point CFFT/CIFFT structure.
|
||||
* @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_cfft_radix2_q15(
|
||||
const arm_cfft_radix2_instance_q15 * S,
|
||||
q15_t * pSrc)
|
||||
{
|
||||
|
||||
if(S->ifftFlag == 1u)
|
||||
{
|
||||
arm_radix2_butterfly_inverse_q15(pSrc, S->fftLen,
|
||||
S->pTwiddle, S->twidCoefModifier);
|
||||
}
|
||||
else
|
||||
{
|
||||
arm_radix2_butterfly_q15(pSrc, S->fftLen,
|
||||
S->pTwiddle, S->twidCoefModifier);
|
||||
}
|
||||
|
||||
arm_bitreversal_q15(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
||||
|
||||
void arm_radix2_butterfly_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pCoef,
|
||||
uint16_t twidCoefModifier)
|
||||
{
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
unsigned i, j, k, l;
|
||||
unsigned n1, n2, ia;
|
||||
q15_t in;
|
||||
q31_t T, S, R;
|
||||
q31_t coeff, out1, out2;
|
||||
|
||||
//N = fftLen;
|
||||
n2 = fftLen;
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (i = 0; i < n2; i++)
|
||||
{
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
in = ((int16_t) (T & 0xFFFF)) >> 2;
|
||||
T = ((T >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
in = ((int16_t) (S & 0xFFFF)) >> 2;
|
||||
S = ((S >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUAD(coeff, R) >> 16;
|
||||
out2 = __SMUSDX(coeff, R);
|
||||
|
||||
#else
|
||||
|
||||
out1 = __SMUSDX(R, coeff) >> 16u;
|
||||
out2 = __SMUAD(coeff, R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i++;
|
||||
l++;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
in = ((int16_t) (T & 0xFFFF)) >> 2;
|
||||
T = ((T >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
in = ((int16_t) (S & 0xFFFF)) >> 2;
|
||||
S = ((S >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUAD(coeff, R) >> 16;
|
||||
out2 = __SMUSDX(coeff, R);
|
||||
|
||||
#else
|
||||
|
||||
out1 = __SMUSDX(R, coeff) >> 16u;
|
||||
out2 = __SMUAD(coeff, R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUAD(coeff, R) >> 16;
|
||||
out2 = __SMUSDX(coeff, R);
|
||||
|
||||
#else
|
||||
|
||||
out1 = __SMUSDX(R, coeff) >> 16u;
|
||||
out2 = __SMUAD(coeff, R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
i += n1;
|
||||
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUAD(coeff, R) >> 16;
|
||||
out2 = __SMUSDX(coeff, R);
|
||||
|
||||
#else
|
||||
|
||||
out1 = __SMUSDX(R, coeff) >> 16u;
|
||||
out2 = __SMUAD(coeff, R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __QADD16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) = R;
|
||||
|
||||
i += n1;
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __QADD16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) = R;
|
||||
|
||||
} // groups loop end
|
||||
|
||||
|
||||
#else
|
||||
|
||||
unsigned i, j, k, l;
|
||||
unsigned n1, n2, ia;
|
||||
q15_t xt, yt, cosVal, sinVal;
|
||||
|
||||
|
||||
//N = fftLen;
|
||||
n2 = fftLen;
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u);
|
||||
pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u;
|
||||
|
||||
yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u);
|
||||
pSrc[2 * i + 1] =
|
||||
((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u;
|
||||
|
||||
pSrc[2u * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) +
|
||||
((int16_t) (((q31_t) yt * sinVal) >> 16)));
|
||||
|
||||
pSrc[2u * l + 1u] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) -
|
||||
((int16_t) (((q31_t) xt * sinVal) >> 16)));
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
|
||||
|
||||
pSrc[2u * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) +
|
||||
((int16_t) (((q31_t) yt * sinVal) >> 16)));
|
||||
|
||||
pSrc[2u * l + 1u] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) -
|
||||
((int16_t) (((q31_t) xt * sinVal) >> 16)));
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
||||
|
||||
pSrc[2u * l] = xt;
|
||||
|
||||
pSrc[2u * l + 1u] = yt;
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
#endif // #ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
}
|
||||
|
||||
|
||||
void arm_radix2_butterfly_inverse_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pCoef,
|
||||
uint16_t twidCoefModifier)
|
||||
{
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
unsigned i, j, k, l;
|
||||
unsigned n1, n2, ia;
|
||||
q15_t in;
|
||||
q31_t T, S, R;
|
||||
q31_t coeff, out1, out2;
|
||||
|
||||
//N = fftLen;
|
||||
n2 = fftLen;
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (i = 0; i < n2; i++)
|
||||
{
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
in = ((int16_t) (T & 0xFFFF)) >> 2;
|
||||
T = ((T >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
in = ((int16_t) (S & 0xFFFF)) >> 2;
|
||||
S = ((S >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUSD(coeff, R) >> 16;
|
||||
out2 = __SMUADX(coeff, R);
|
||||
#else
|
||||
|
||||
out1 = __SMUADX(R, coeff) >> 16u;
|
||||
out2 = __SMUSD(__QSUB(0, coeff), R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i++;
|
||||
l++;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
in = ((int16_t) (T & 0xFFFF)) >> 2;
|
||||
T = ((T >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
in = ((int16_t) (S & 0xFFFF)) >> 2;
|
||||
S = ((S >> 2) & 0xFFFF0000) | (in & 0xFFFF);
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUSD(coeff, R) >> 16;
|
||||
out2 = __SMUADX(coeff, R);
|
||||
#else
|
||||
|
||||
out1 = __SMUADX(R, coeff) >> 16u;
|
||||
out2 = __SMUSD(__QSUB(0, coeff), R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUSD(coeff, R) >> 16;
|
||||
out2 = __SMUADX(coeff, R);
|
||||
|
||||
#else
|
||||
|
||||
out1 = __SMUADX(R, coeff) >> 16u;
|
||||
out2 = __SMUSD(__QSUB(0, coeff), R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
i += n1;
|
||||
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
out1 = __SMUSD(coeff, R) >> 16;
|
||||
out2 = __SMUADX(coeff, R);
|
||||
#else
|
||||
|
||||
out1 = __SMUADX(R, coeff) >> 16u;
|
||||
out2 = __SMUSD(__QSUB(0, coeff), R);
|
||||
|
||||
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) =
|
||||
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
coeff = _SIMD32_OFFSET(pCoef + (ia * 2u));
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
|
||||
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
||||
|
||||
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
||||
|
||||
R = __QSUB16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2 * i)) = __QADD16(T, S);
|
||||
|
||||
_SIMD32_OFFSET(pSrc + (2u * l)) = R;
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
#else
|
||||
|
||||
|
||||
unsigned i, j, k, l;
|
||||
unsigned n1, n2, ia;
|
||||
q15_t xt, yt, cosVal, sinVal;
|
||||
|
||||
//N = fftLen;
|
||||
n2 = fftLen;
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u);
|
||||
pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u;
|
||||
|
||||
yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u);
|
||||
pSrc[2 * i + 1] =
|
||||
((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u;
|
||||
|
||||
pSrc[2u * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) -
|
||||
((int16_t) (((q31_t) yt * sinVal) >> 16)));
|
||||
|
||||
pSrc[2u * l + 1u] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) +
|
||||
((int16_t) (((q31_t) xt * sinVal) >> 16)));
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
|
||||
|
||||
pSrc[2u * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) -
|
||||
((int16_t) (((q31_t) yt * sinVal) >> 16)));
|
||||
|
||||
pSrc[2u * l + 1u] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) +
|
||||
((int16_t) (((q31_t) xt * sinVal) >> 16)));
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
||||
|
||||
pSrc[2u * l] = xt;
|
||||
|
||||
pSrc[2u * l + 1u] = yt;
|
||||
|
||||
} // groups loop end
|
||||
|
||||
|
||||
#endif // #ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
}
|
@ -0,0 +1,350 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix2_q31.c
|
||||
*
|
||||
* Description: Radix-2 Decimation in Frequency CFFT & CIFFT Fixed point processing function
|
||||
*
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void arm_radix2_butterfly_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
void arm_radix2_butterfly_inverse_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
void arm_bitreversal_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @details
|
||||
* @brief Processing function for the fixed-point CFFT/CIFFT.
|
||||
* @param[in] *S points to an instance of the fixed-point CFFT/CIFFT structure.
|
||||
* @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_cfft_radix2_q31(
|
||||
const arm_cfft_radix2_instance_q31 * S,
|
||||
q31_t * pSrc)
|
||||
{
|
||||
|
||||
if(S->ifftFlag == 1u)
|
||||
{
|
||||
arm_radix2_butterfly_inverse_q31(pSrc, S->fftLen,
|
||||
S->pTwiddle, S->twidCoefModifier);
|
||||
}
|
||||
else
|
||||
{
|
||||
arm_radix2_butterfly_q31(pSrc, S->fftLen,
|
||||
S->pTwiddle, S->twidCoefModifier);
|
||||
}
|
||||
|
||||
arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
||||
|
||||
void arm_radix2_butterfly_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint16_t twidCoefModifier)
|
||||
{
|
||||
|
||||
unsigned i, j, k, l, m;
|
||||
unsigned n1, n2, ia;
|
||||
q31_t xt, yt, cosVal, sinVal;
|
||||
q31_t p0, p1;
|
||||
|
||||
//N = fftLen;
|
||||
n2 = fftLen;
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (i = 0; i < n2; i++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
l = i + n2;
|
||||
xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u);
|
||||
pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u;
|
||||
|
||||
yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u);
|
||||
pSrc[2 * i + 1] =
|
||||
((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u;
|
||||
|
||||
mult_32x32_keep32_R(p0, xt, cosVal);
|
||||
mult_32x32_keep32_R(p1, yt, cosVal);
|
||||
multAcc_32x32_keep32_R(p0, yt, sinVal);
|
||||
multSub_32x32_keep32_R(p1, xt, sinVal);
|
||||
|
||||
pSrc[2u * l] = p0;
|
||||
pSrc[2u * l + 1u] = p1;
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier <<= 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
i = j;
|
||||
m = fftLen / n1;
|
||||
do
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
|
||||
|
||||
mult_32x32_keep32_R(p0, xt, cosVal);
|
||||
mult_32x32_keep32_R(p1, yt, cosVal);
|
||||
multAcc_32x32_keep32_R(p0, yt, sinVal);
|
||||
multSub_32x32_keep32_R(p1, xt, sinVal);
|
||||
|
||||
pSrc[2u * l] = p0;
|
||||
pSrc[2u * l + 1u] = p1;
|
||||
i += n1;
|
||||
m--;
|
||||
} while( m > 0); // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier <<= 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
||||
|
||||
pSrc[2u * l] = xt;
|
||||
|
||||
pSrc[2u * l + 1u] = yt;
|
||||
|
||||
i += n1;
|
||||
l = i + n2;
|
||||
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
||||
|
||||
pSrc[2u * l] = xt;
|
||||
|
||||
pSrc[2u * l + 1u] = yt;
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
}
|
||||
|
||||
|
||||
void arm_radix2_butterfly_inverse_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint16_t twidCoefModifier)
|
||||
{
|
||||
|
||||
unsigned i, j, k, l;
|
||||
unsigned n1, n2, ia;
|
||||
q31_t xt, yt, cosVal, sinVal;
|
||||
q31_t p0, p1;
|
||||
|
||||
//N = fftLen;
|
||||
n2 = fftLen;
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (i = 0; i < n2; i++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
l = i + n2;
|
||||
xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u);
|
||||
pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u;
|
||||
|
||||
yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u);
|
||||
pSrc[2 * i + 1] =
|
||||
((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u;
|
||||
|
||||
mult_32x32_keep32_R(p0, xt, cosVal);
|
||||
mult_32x32_keep32_R(p1, yt, cosVal);
|
||||
multSub_32x32_keep32_R(p0, yt, sinVal);
|
||||
multAcc_32x32_keep32_R(p1, xt, sinVal);
|
||||
|
||||
pSrc[2u * l] = p0;
|
||||
pSrc[2u * l + 1u] = p1;
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
|
||||
// loop for stage
|
||||
for (k = fftLen / 2; k > 2; k = k >> 1)
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
// loop for groups
|
||||
for (j = 0; j < n2; j++)
|
||||
{
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = j; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
|
||||
|
||||
mult_32x32_keep32_R(p0, xt, cosVal);
|
||||
mult_32x32_keep32_R(p1, yt, cosVal);
|
||||
multSub_32x32_keep32_R(p0, yt, sinVal);
|
||||
multAcc_32x32_keep32_R(p1, xt, sinVal);
|
||||
|
||||
pSrc[2u * l] = p0;
|
||||
pSrc[2u * l + 1u] = p1;
|
||||
} // butterfly loop end
|
||||
|
||||
} // groups loop end
|
||||
|
||||
twidCoefModifier = twidCoefModifier << 1u;
|
||||
} // stages loop end
|
||||
|
||||
n1 = n2;
|
||||
n2 = n2 >> 1;
|
||||
ia = 0;
|
||||
|
||||
cosVal = pCoef[ia * 2];
|
||||
sinVal = pCoef[(ia * 2) + 1];
|
||||
ia = ia + twidCoefModifier;
|
||||
|
||||
// loop for butterfly
|
||||
for (i = 0; i < fftLen; i += n1)
|
||||
{
|
||||
l = i + n2;
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
||||
|
||||
pSrc[2u * l] = xt;
|
||||
|
||||
pSrc[2u * l + 1u] = yt;
|
||||
|
||||
i += n1;
|
||||
l = i + n2;
|
||||
|
||||
xt = pSrc[2 * i] - pSrc[2 * l];
|
||||
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
||||
|
||||
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
||||
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
||||
|
||||
pSrc[2u * l] = xt;
|
||||
|
||||
pSrc[2u * l + 1u] = yt;
|
||||
|
||||
} // butterfly loop end
|
||||
|
||||
}
|
File diff suppressed because it is too large
Load Diff
@ -0,0 +1,165 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix4_init_f32.c
|
||||
*
|
||||
* Description: Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT Initialization function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Initialization function for the floating-point CFFT/CIFFT.
|
||||
* @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f32 and will be removed
|
||||
* in the future.
|
||||
* @param[in,out] *S points to an instance of the floating-point CFFT/CIFFT structure.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
|
||||
arm_status arm_cfft_radix4_init_f32(
|
||||
arm_cfft_radix4_instance_f32 * S,
|
||||
uint16_t fftLen,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
|
||||
/* Initialise the FFT length */
|
||||
S->fftLen = fftLen;
|
||||
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
S->pTwiddle = (float32_t *) twiddleCoef;
|
||||
|
||||
/* Initialise the Flag for selection of CFFT or CIFFT */
|
||||
S->ifftFlag = ifftFlag;
|
||||
|
||||
/* Initialise the Flag for calculation Bit reversal or not */
|
||||
S->bitReverseFlag = bitReverseFlag;
|
||||
|
||||
/* Initializations of structure parameters depending on the FFT length */
|
||||
switch (S->fftLen)
|
||||
{
|
||||
|
||||
case 4096u:
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 1u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 1u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) armBitRevTable;
|
||||
/* Initialise the 1/fftLen Value */
|
||||
S->onebyfftLen = 0.000244140625;
|
||||
break;
|
||||
|
||||
case 1024u:
|
||||
/* Initializations of structure parameters for 1024 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 4u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 4u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
|
||||
/* Initialise the 1/fftLen Value */
|
||||
S->onebyfftLen = 0.0009765625f;
|
||||
break;
|
||||
|
||||
|
||||
case 256u:
|
||||
/* Initializations of structure parameters for 256 point FFT */
|
||||
S->twidCoefModifier = 16u;
|
||||
S->bitRevFactor = 16u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
|
||||
S->onebyfftLen = 0.00390625f;
|
||||
break;
|
||||
|
||||
case 64u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 64u;
|
||||
S->bitRevFactor = 64u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
|
||||
S->onebyfftLen = 0.015625f;
|
||||
break;
|
||||
|
||||
case 16u:
|
||||
/* Initializations of structure parameters for 16 point FFT */
|
||||
S->twidCoefModifier = 256u;
|
||||
S->bitRevFactor = 256u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
|
||||
S->onebyfftLen = 0.0625f;
|
||||
break;
|
||||
|
||||
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
@ -0,0 +1,151 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix4_init_q15.c
|
||||
*
|
||||
* Description: Radix-4 Decimation in Frequency Q15 FFT & IFFT initialization function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
|
||||
/**
|
||||
* @brief Initialization function for the Q15 CFFT/CIFFT.
|
||||
* @param[in,out] *S points to an instance of the Q15 CFFT/CIFFT structure.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
|
||||
arm_status arm_cfft_radix4_init_q15(
|
||||
arm_cfft_radix4_instance_q15 * S,
|
||||
uint16_t fftLen,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
/* Initialise the FFT length */
|
||||
S->fftLen = fftLen;
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
S->pTwiddle = (q15_t *) twiddleCoefQ15;
|
||||
/* Initialise the Flag for selection of CFFT or CIFFT */
|
||||
S->ifftFlag = ifftFlag;
|
||||
/* Initialise the Flag for calculation Bit reversal or not */
|
||||
S->bitReverseFlag = bitReverseFlag;
|
||||
|
||||
/* Initializations of structure parameters depending on the FFT length */
|
||||
switch (S->fftLen)
|
||||
{
|
||||
case 4096u:
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 1u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 1u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) armBitRevTable;
|
||||
|
||||
break;
|
||||
|
||||
case 1024u:
|
||||
/* Initializations of structure parameters for 1024 point FFT */
|
||||
S->twidCoefModifier = 4u;
|
||||
S->bitRevFactor = 4u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
|
||||
|
||||
break;
|
||||
|
||||
case 256u:
|
||||
/* Initializations of structure parameters for 256 point FFT */
|
||||
S->twidCoefModifier = 16u;
|
||||
S->bitRevFactor = 16u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
|
||||
|
||||
break;
|
||||
|
||||
case 64u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 64u;
|
||||
S->bitRevFactor = 64u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
|
||||
|
||||
break;
|
||||
|
||||
case 16u:
|
||||
/* Initializations of structure parameters for 16 point FFT */
|
||||
S->twidCoefModifier = 256u;
|
||||
S->bitRevFactor = 256u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
|
||||
|
||||
break;
|
||||
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
@ -0,0 +1,147 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix4_init_q31.c
|
||||
*
|
||||
* Description: Radix-4 Decimation in Frequency Q31 FFT & IFFT initialization function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
*
|
||||
* @brief Initialization function for the Q31 CFFT/CIFFT.
|
||||
* @param[in,out] *S points to an instance of the Q31 CFFT/CIFFT structure.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
|
||||
* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
|
||||
arm_status arm_cfft_radix4_init_q31(
|
||||
arm_cfft_radix4_instance_q31 * S,
|
||||
uint16_t fftLen,
|
||||
uint8_t ifftFlag,
|
||||
uint8_t bitReverseFlag)
|
||||
{
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
/* Initialise the FFT length */
|
||||
S->fftLen = fftLen;
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
S->pTwiddle = (q31_t *) twiddleCoefQ31;
|
||||
/* Initialise the Flag for selection of CFFT or CIFFT */
|
||||
S->ifftFlag = ifftFlag;
|
||||
/* Initialise the Flag for calculation Bit reversal or not */
|
||||
S->bitReverseFlag = bitReverseFlag;
|
||||
|
||||
/* Initializations of Instance structure depending on the FFT length */
|
||||
switch (S->fftLen)
|
||||
{
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
case 4096u:
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 1u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 1u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) armBitRevTable;
|
||||
break;
|
||||
|
||||
/* Initializations of structure parameters for 1024 point FFT */
|
||||
case 1024u:
|
||||
/* Initialise the twiddle coef modifier value */
|
||||
S->twidCoefModifier = 4u;
|
||||
/* Initialise the bit reversal table modifier */
|
||||
S->bitRevFactor = 4u;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
|
||||
break;
|
||||
|
||||
case 256u:
|
||||
/* Initializations of structure parameters for 256 point FFT */
|
||||
S->twidCoefModifier = 16u;
|
||||
S->bitRevFactor = 16u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
|
||||
break;
|
||||
|
||||
case 64u:
|
||||
/* Initializations of structure parameters for 64 point FFT */
|
||||
S->twidCoefModifier = 64u;
|
||||
S->bitRevFactor = 64u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
|
||||
break;
|
||||
|
||||
case 16u:
|
||||
/* Initializations of structure parameters for 16 point FFT */
|
||||
S->twidCoefModifier = 256u;
|
||||
S->bitRevFactor = 256u;
|
||||
S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
|
||||
break;
|
||||
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
File diff suppressed because it is too large
Load Diff
@ -0,0 +1,911 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix4_q31.c
|
||||
*
|
||||
* Description: This file has function definition of Radix-4 FFT & IFFT function and
|
||||
* In-place bit reversal using bit reversal table
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void arm_radix4_butterfly_inverse_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint32_t twidCoefModifier);
|
||||
|
||||
void arm_radix4_butterfly_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint32_t twidCoefModifier);
|
||||
|
||||
void arm_bitreversal_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup ComplexFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @details
|
||||
* @brief Processing function for the Q31 CFFT/CIFFT.
|
||||
* @param[in] *S points to an instance of the Q31 CFFT/CIFFT structure.
|
||||
* @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
|
||||
* @return none.
|
||||
*
|
||||
* \par Input and output formats:
|
||||
* \par
|
||||
* Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process.
|
||||
* Hence the output format is different for different FFT sizes.
|
||||
* The input and output formats for different FFT sizes and number of bits to upscale are mentioned in the tables below for CFFT and CIFFT:
|
||||
* \par
|
||||
* \image html CFFTQ31.gif "Input and Output Formats for Q31 CFFT"
|
||||
* \image html CIFFTQ31.gif "Input and Output Formats for Q31 CIFFT"
|
||||
*
|
||||
*/
|
||||
|
||||
void arm_cfft_radix4_q31(
|
||||
const arm_cfft_radix4_instance_q31 * S,
|
||||
q31_t * pSrc)
|
||||
{
|
||||
if(S->ifftFlag == 1u)
|
||||
{
|
||||
/* Complex IFFT radix-4 */
|
||||
arm_radix4_butterfly_inverse_q31(pSrc, S->fftLen, S->pTwiddle,
|
||||
S->twidCoefModifier);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Complex FFT radix-4 */
|
||||
arm_radix4_butterfly_q31(pSrc, S->fftLen, S->pTwiddle,
|
||||
S->twidCoefModifier);
|
||||
}
|
||||
|
||||
|
||||
if(S->bitReverseFlag == 1u)
|
||||
{
|
||||
/* Bit Reversal */
|
||||
arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of ComplexFFT group
|
||||
*/
|
||||
|
||||
/*
|
||||
* Radix-4 FFT algorithm used is :
|
||||
*
|
||||
* Input real and imaginary data:
|
||||
* x(n) = xa + j * ya
|
||||
* x(n+N/4 ) = xb + j * yb
|
||||
* x(n+N/2 ) = xc + j * yc
|
||||
* x(n+3N 4) = xd + j * yd
|
||||
*
|
||||
*
|
||||
* Output real and imaginary data:
|
||||
* x(4r) = xa'+ j * ya'
|
||||
* x(4r+1) = xb'+ j * yb'
|
||||
* x(4r+2) = xc'+ j * yc'
|
||||
* x(4r+3) = xd'+ j * yd'
|
||||
*
|
||||
*
|
||||
* Twiddle factors for radix-4 FFT:
|
||||
* Wn = co1 + j * (- si1)
|
||||
* W2n = co2 + j * (- si2)
|
||||
* W3n = co3 + j * (- si3)
|
||||
*
|
||||
* Butterfly implementation:
|
||||
* xa' = xa + xb + xc + xd
|
||||
* ya' = ya + yb + yc + yd
|
||||
* xb' = (xa+yb-xc-yd)* co1 + (ya-xb-yc+xd)* (si1)
|
||||
* yb' = (ya-xb-yc+xd)* co1 - (xa+yb-xc-yd)* (si1)
|
||||
* xc' = (xa-xb+xc-xd)* co2 + (ya-yb+yc-yd)* (si2)
|
||||
* yc' = (ya-yb+yc-yd)* co2 - (xa-xb+xc-xd)* (si2)
|
||||
* xd' = (xa-yb-xc+yd)* co3 + (ya+xb-yc-xd)* (si3)
|
||||
* yd' = (ya+xb-yc-xd)* co3 - (xa-yb-xc+yd)* (si3)
|
||||
*
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Core function for the Q31 CFFT butterfly process.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] *pCoef points to twiddle coefficient buffer.
|
||||
* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_radix4_butterfly_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint32_t twidCoefModifier)
|
||||
{
|
||||
uint32_t n1, n2, ia1, ia2, ia3, i0, i1, i2, i3, j, k;
|
||||
q31_t t1, t2, r1, r2, s1, s2, co1, co2, co3, si1, si2, si3;
|
||||
|
||||
q31_t xa, xb, xc, xd;
|
||||
q31_t ya, yb, yc, yd;
|
||||
q31_t xa_out, xb_out, xc_out, xd_out;
|
||||
q31_t ya_out, yb_out, yc_out, yd_out;
|
||||
|
||||
q31_t *ptr1;
|
||||
q63_t xaya, xbyb, xcyc, xdyd;
|
||||
/* Total process is divided into three stages */
|
||||
|
||||
/* process first stage, middle stages, & last stage */
|
||||
|
||||
|
||||
/* start of first stage process */
|
||||
|
||||
/* Initializations for the first stage */
|
||||
n2 = fftLen;
|
||||
n1 = n2;
|
||||
/* n2 = fftLen/4 */
|
||||
n2 >>= 2u;
|
||||
i0 = 0u;
|
||||
ia1 = 0u;
|
||||
|
||||
j = n2;
|
||||
|
||||
/* Calculation of first stage */
|
||||
do
|
||||
{
|
||||
/* index calculation for the input as, */
|
||||
/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2u], pSrc[i0 + 3fftLen/4] */
|
||||
i1 = i0 + n2;
|
||||
i2 = i1 + n2;
|
||||
i3 = i2 + n2;
|
||||
|
||||
/* input is in 1.31(q31) format and provide 4 guard bits for the input */
|
||||
|
||||
/* Butterfly implementation */
|
||||
/* xa + xc */
|
||||
r1 = (pSrc[(2u * i0)] >> 4u) + (pSrc[(2u * i2)] >> 4u);
|
||||
/* xa - xc */
|
||||
r2 = (pSrc[2u * i0] >> 4u) - (pSrc[2u * i2] >> 4u);
|
||||
|
||||
/* xb + xd */
|
||||
t1 = (pSrc[2u * i1] >> 4u) + (pSrc[2u * i3] >> 4u);
|
||||
|
||||
/* ya + yc */
|
||||
s1 = (pSrc[(2u * i0) + 1u] >> 4u) + (pSrc[(2u * i2) + 1u] >> 4u);
|
||||
/* ya - yc */
|
||||
s2 = (pSrc[(2u * i0) + 1u] >> 4u) - (pSrc[(2u * i2) + 1u] >> 4u);
|
||||
|
||||
/* xa' = xa + xb + xc + xd */
|
||||
pSrc[2u * i0] = (r1 + t1);
|
||||
/* (xa + xc) - (xb + xd) */
|
||||
r1 = r1 - t1;
|
||||
/* yb + yd */
|
||||
t2 = (pSrc[(2u * i1) + 1u] >> 4u) + (pSrc[(2u * i3) + 1u] >> 4u);
|
||||
|
||||
/* ya' = ya + yb + yc + yd */
|
||||
pSrc[(2u * i0) + 1u] = (s1 + t2);
|
||||
|
||||
/* (ya + yc) - (yb + yd) */
|
||||
s1 = s1 - t2;
|
||||
|
||||
/* yb - yd */
|
||||
t1 = (pSrc[(2u * i1) + 1u] >> 4u) - (pSrc[(2u * i3) + 1u] >> 4u);
|
||||
/* xb - xd */
|
||||
t2 = (pSrc[2u * i1] >> 4u) - (pSrc[2u * i3] >> 4u);
|
||||
|
||||
/* index calculation for the coefficients */
|
||||
ia2 = 2u * ia1;
|
||||
co2 = pCoef[ia2 * 2u];
|
||||
si2 = pCoef[(ia2 * 2u) + 1u];
|
||||
|
||||
/* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
|
||||
pSrc[2u * i1] = (((int32_t) (((q63_t) r1 * co2) >> 32)) +
|
||||
((int32_t) (((q63_t) s1 * si2) >> 32))) << 1u;
|
||||
|
||||
/* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
|
||||
pSrc[(2u * i1) + 1u] = (((int32_t) (((q63_t) s1 * co2) >> 32)) -
|
||||
((int32_t) (((q63_t) r1 * si2) >> 32))) << 1u;
|
||||
|
||||
/* (xa - xc) + (yb - yd) */
|
||||
r1 = r2 + t1;
|
||||
/* (xa - xc) - (yb - yd) */
|
||||
r2 = r2 - t1;
|
||||
|
||||
/* (ya - yc) - (xb - xd) */
|
||||
s1 = s2 - t2;
|
||||
/* (ya - yc) + (xb - xd) */
|
||||
s2 = s2 + t2;
|
||||
|
||||
co1 = pCoef[ia1 * 2u];
|
||||
si1 = pCoef[(ia1 * 2u) + 1u];
|
||||
|
||||
/* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
|
||||
pSrc[2u * i2] = (((int32_t) (((q63_t) r1 * co1) >> 32)) +
|
||||
((int32_t) (((q63_t) s1 * si1) >> 32))) << 1u;
|
||||
|
||||
/* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
|
||||
pSrc[(2u * i2) + 1u] = (((int32_t) (((q63_t) s1 * co1) >> 32)) -
|
||||
((int32_t) (((q63_t) r1 * si1) >> 32))) << 1u;
|
||||
|
||||
/* index calculation for the coefficients */
|
||||
ia3 = 3u * ia1;
|
||||
co3 = pCoef[ia3 * 2u];
|
||||
si3 = pCoef[(ia3 * 2u) + 1u];
|
||||
|
||||
/* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
|
||||
pSrc[2u * i3] = (((int32_t) (((q63_t) r2 * co3) >> 32)) +
|
||||
((int32_t) (((q63_t) s2 * si3) >> 32))) << 1u;
|
||||
|
||||
/* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
|
||||
pSrc[(2u * i3) + 1u] = (((int32_t) (((q63_t) s2 * co3) >> 32)) -
|
||||
((int32_t) (((q63_t) r2 * si3) >> 32))) << 1u;
|
||||
|
||||
/* Twiddle coefficients index modifier */
|
||||
ia1 = ia1 + twidCoefModifier;
|
||||
|
||||
/* Updating input index */
|
||||
i0 = i0 + 1u;
|
||||
|
||||
} while(--j);
|
||||
|
||||
/* end of first stage process */
|
||||
|
||||
/* data is in 5.27(q27) format */
|
||||
|
||||
|
||||
/* start of Middle stages process */
|
||||
|
||||
|
||||
/* each stage in middle stages provides two down scaling of the input */
|
||||
|
||||
twidCoefModifier <<= 2u;
|
||||
|
||||
|
||||
for (k = fftLen / 4u; k > 4u; k >>= 2u)
|
||||
{
|
||||
/* Initializations for the first stage */
|
||||
n1 = n2;
|
||||
n2 >>= 2u;
|
||||
ia1 = 0u;
|
||||
|
||||
/* Calculation of first stage */
|
||||
for (j = 0u; j <= (n2 - 1u); j++)
|
||||
{
|
||||
/* index calculation for the coefficients */
|
||||
ia2 = ia1 + ia1;
|
||||
ia3 = ia2 + ia1;
|
||||
co1 = pCoef[ia1 * 2u];
|
||||
si1 = pCoef[(ia1 * 2u) + 1u];
|
||||
co2 = pCoef[ia2 * 2u];
|
||||
si2 = pCoef[(ia2 * 2u) + 1u];
|
||||
co3 = pCoef[ia3 * 2u];
|
||||
si3 = pCoef[(ia3 * 2u) + 1u];
|
||||
/* Twiddle coefficients index modifier */
|
||||
ia1 = ia1 + twidCoefModifier;
|
||||
|
||||
for (i0 = j; i0 < fftLen; i0 += n1)
|
||||
{
|
||||
/* index calculation for the input as, */
|
||||
/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2u], pSrc[i0 + 3fftLen/4] */
|
||||
i1 = i0 + n2;
|
||||
i2 = i1 + n2;
|
||||
i3 = i2 + n2;
|
||||
|
||||
/* Butterfly implementation */
|
||||
/* xa + xc */
|
||||
r1 = pSrc[2u * i0] + pSrc[2u * i2];
|
||||
/* xa - xc */
|
||||
r2 = pSrc[2u * i0] - pSrc[2u * i2];
|
||||
|
||||
/* ya + yc */
|
||||
s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
|
||||
/* ya - yc */
|
||||
s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
|
||||
|
||||
/* xb + xd */
|
||||
t1 = pSrc[2u * i1] + pSrc[2u * i3];
|
||||
|
||||
/* xa' = xa + xb + xc + xd */
|
||||
pSrc[2u * i0] = (r1 + t1) >> 2u;
|
||||
/* xa + xc -(xb + xd) */
|
||||
r1 = r1 - t1;
|
||||
|
||||
/* yb + yd */
|
||||
t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
|
||||
/* ya' = ya + yb + yc + yd */
|
||||
pSrc[(2u * i0) + 1u] = (s1 + t2) >> 2u;
|
||||
|
||||
/* (ya + yc) - (yb + yd) */
|
||||
s1 = s1 - t2;
|
||||
|
||||
/* (yb - yd) */
|
||||
t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
|
||||
/* (xb - xd) */
|
||||
t2 = pSrc[2u * i1] - pSrc[2u * i3];
|
||||
|
||||
/* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
|
||||
pSrc[2u * i1] = (((int32_t) (((q63_t) r1 * co2) >> 32)) +
|
||||
((int32_t) (((q63_t) s1 * si2) >> 32))) >> 1u;
|
||||
|
||||
/* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
|
||||
pSrc[(2u * i1) + 1u] = (((int32_t) (((q63_t) s1 * co2) >> 32)) -
|
||||
((int32_t) (((q63_t) r1 * si2) >> 32))) >> 1u;
|
||||
|
||||
/* (xa - xc) + (yb - yd) */
|
||||
r1 = r2 + t1;
|
||||
/* (xa - xc) - (yb - yd) */
|
||||
r2 = r2 - t1;
|
||||
|
||||
/* (ya - yc) - (xb - xd) */
|
||||
s1 = s2 - t2;
|
||||
/* (ya - yc) + (xb - xd) */
|
||||
s2 = s2 + t2;
|
||||
|
||||
/* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
|
||||
pSrc[2u * i2] = (((int32_t) (((q63_t) r1 * co1) >> 32)) +
|
||||
((int32_t) (((q63_t) s1 * si1) >> 32))) >> 1u;
|
||||
|
||||
/* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
|
||||
pSrc[(2u * i2) + 1u] = (((int32_t) (((q63_t) s1 * co1) >> 32)) -
|
||||
((int32_t) (((q63_t) r1 * si1) >> 32))) >> 1u;
|
||||
|
||||
/* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
|
||||
pSrc[2u * i3] = (((int32_t) (((q63_t) r2 * co3) >> 32)) +
|
||||
((int32_t) (((q63_t) s2 * si3) >> 32))) >> 1u;
|
||||
|
||||
/* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
|
||||
pSrc[(2u * i3) + 1u] = (((int32_t) (((q63_t) s2 * co3) >> 32)) -
|
||||
((int32_t) (((q63_t) r2 * si3) >> 32))) >> 1u;
|
||||
}
|
||||
}
|
||||
twidCoefModifier <<= 2u;
|
||||
}
|
||||
|
||||
/* End of Middle stages process */
|
||||
|
||||
/* data is in 11.21(q21) format for the 1024 point as there are 3 middle stages */
|
||||
/* data is in 9.23(q23) format for the 256 point as there are 2 middle stages */
|
||||
/* data is in 7.25(q25) format for the 64 point as there are 1 middle stage */
|
||||
/* data is in 5.27(q27) format for the 16 point as there are no middle stages */
|
||||
|
||||
|
||||
/* start of Last stage process */
|
||||
/* Initializations for the last stage */
|
||||
j = fftLen >> 2;
|
||||
ptr1 = &pSrc[0];
|
||||
|
||||
/* Calculations of last stage */
|
||||
do
|
||||
{
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
/* Read xa (real), ya(imag) input */
|
||||
xaya = *__SIMD64(ptr1)++;
|
||||
xa = (q31_t) xaya;
|
||||
ya = (q31_t) (xaya >> 32);
|
||||
|
||||
/* Read xb (real), yb(imag) input */
|
||||
xbyb = *__SIMD64(ptr1)++;
|
||||
xb = (q31_t) xbyb;
|
||||
yb = (q31_t) (xbyb >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xcyc = *__SIMD64(ptr1)++;
|
||||
xc = (q31_t) xcyc;
|
||||
yc = (q31_t) (xcyc >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xdyd = *__SIMD64(ptr1)++;
|
||||
xd = (q31_t) xdyd;
|
||||
yd = (q31_t) (xdyd >> 32);
|
||||
|
||||
#else
|
||||
|
||||
/* Read xa (real), ya(imag) input */
|
||||
xaya = *__SIMD64(ptr1)++;
|
||||
ya = (q31_t) xaya;
|
||||
xa = (q31_t) (xaya >> 32);
|
||||
|
||||
/* Read xb (real), yb(imag) input */
|
||||
xbyb = *__SIMD64(ptr1)++;
|
||||
yb = (q31_t) xbyb;
|
||||
xb = (q31_t) (xbyb >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xcyc = *__SIMD64(ptr1)++;
|
||||
yc = (q31_t) xcyc;
|
||||
xc = (q31_t) (xcyc >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xdyd = *__SIMD64(ptr1)++;
|
||||
yd = (q31_t) xdyd;
|
||||
xd = (q31_t) (xdyd >> 32);
|
||||
|
||||
|
||||
#endif
|
||||
|
||||
/* xa' = xa + xb + xc + xd */
|
||||
xa_out = xa + xb + xc + xd;
|
||||
|
||||
/* ya' = ya + yb + yc + yd */
|
||||
ya_out = ya + yb + yc + yd;
|
||||
|
||||
/* pointer updation for writing */
|
||||
ptr1 = ptr1 - 8u;
|
||||
|
||||
/* writing xa' and ya' */
|
||||
*ptr1++ = xa_out;
|
||||
*ptr1++ = ya_out;
|
||||
|
||||
xc_out = (xa - xb + xc - xd);
|
||||
yc_out = (ya - yb + yc - yd);
|
||||
|
||||
/* writing xc' and yc' */
|
||||
*ptr1++ = xc_out;
|
||||
*ptr1++ = yc_out;
|
||||
|
||||
xb_out = (xa + yb - xc - yd);
|
||||
yb_out = (ya - xb - yc + xd);
|
||||
|
||||
/* writing xb' and yb' */
|
||||
*ptr1++ = xb_out;
|
||||
*ptr1++ = yb_out;
|
||||
|
||||
xd_out = (xa - yb - xc + yd);
|
||||
yd_out = (ya + xb - yc - xd);
|
||||
|
||||
/* writing xd' and yd' */
|
||||
*ptr1++ = xd_out;
|
||||
*ptr1++ = yd_out;
|
||||
|
||||
|
||||
} while(--j);
|
||||
|
||||
/* output is in 11.21(q21) format for the 1024 point */
|
||||
/* output is in 9.23(q23) format for the 256 point */
|
||||
/* output is in 7.25(q25) format for the 64 point */
|
||||
/* output is in 5.27(q27) format for the 16 point */
|
||||
|
||||
/* End of last stage process */
|
||||
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* @brief Core function for the Q31 CIFFT butterfly process.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] *pCoef points to twiddle coefficient buffer.
|
||||
* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
|
||||
/*
|
||||
* Radix-4 IFFT algorithm used is :
|
||||
*
|
||||
* CIFFT uses same twiddle coefficients as CFFT Function
|
||||
* x[k] = x[n] + (j)k * x[n + fftLen/4] + (-1)k * x[n+fftLen/2] + (-j)k * x[n+3*fftLen/4]
|
||||
*
|
||||
*
|
||||
* IFFT is implemented with following changes in equations from FFT
|
||||
*
|
||||
* Input real and imaginary data:
|
||||
* x(n) = xa + j * ya
|
||||
* x(n+N/4 ) = xb + j * yb
|
||||
* x(n+N/2 ) = xc + j * yc
|
||||
* x(n+3N 4) = xd + j * yd
|
||||
*
|
||||
*
|
||||
* Output real and imaginary data:
|
||||
* x(4r) = xa'+ j * ya'
|
||||
* x(4r+1) = xb'+ j * yb'
|
||||
* x(4r+2) = xc'+ j * yc'
|
||||
* x(4r+3) = xd'+ j * yd'
|
||||
*
|
||||
*
|
||||
* Twiddle factors for radix-4 IFFT:
|
||||
* Wn = co1 + j * (si1)
|
||||
* W2n = co2 + j * (si2)
|
||||
* W3n = co3 + j * (si3)
|
||||
|
||||
* The real and imaginary output values for the radix-4 butterfly are
|
||||
* xa' = xa + xb + xc + xd
|
||||
* ya' = ya + yb + yc + yd
|
||||
* xb' = (xa-yb-xc+yd)* co1 - (ya+xb-yc-xd)* (si1)
|
||||
* yb' = (ya+xb-yc-xd)* co1 + (xa-yb-xc+yd)* (si1)
|
||||
* xc' = (xa-xb+xc-xd)* co2 - (ya-yb+yc-yd)* (si2)
|
||||
* yc' = (ya-yb+yc-yd)* co2 + (xa-xb+xc-xd)* (si2)
|
||||
* xd' = (xa+yb-xc-yd)* co3 - (ya-xb-yc+xd)* (si3)
|
||||
* yd' = (ya-xb-yc+xd)* co3 + (xa+yb-xc-yd)* (si3)
|
||||
*
|
||||
*/
|
||||
|
||||
void arm_radix4_butterfly_inverse_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint32_t twidCoefModifier)
|
||||
{
|
||||
uint32_t n1, n2, ia1, ia2, ia3, i0, i1, i2, i3, j, k;
|
||||
q31_t t1, t2, r1, r2, s1, s2, co1, co2, co3, si1, si2, si3;
|
||||
q31_t xa, xb, xc, xd;
|
||||
q31_t ya, yb, yc, yd;
|
||||
q31_t xa_out, xb_out, xc_out, xd_out;
|
||||
q31_t ya_out, yb_out, yc_out, yd_out;
|
||||
|
||||
q31_t *ptr1;
|
||||
q63_t xaya, xbyb, xcyc, xdyd;
|
||||
|
||||
/* input is be 1.31(q31) format for all FFT sizes */
|
||||
/* Total process is divided into three stages */
|
||||
/* process first stage, middle stages, & last stage */
|
||||
|
||||
/* Start of first stage process */
|
||||
|
||||
/* Initializations for the first stage */
|
||||
n2 = fftLen;
|
||||
n1 = n2;
|
||||
/* n2 = fftLen/4 */
|
||||
n2 >>= 2u;
|
||||
i0 = 0u;
|
||||
ia1 = 0u;
|
||||
|
||||
j = n2;
|
||||
|
||||
do
|
||||
{
|
||||
|
||||
/* input is in 1.31(q31) format and provide 4 guard bits for the input */
|
||||
|
||||
/* index calculation for the input as, */
|
||||
/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2u], pSrc[i0 + 3fftLen/4] */
|
||||
i1 = i0 + n2;
|
||||
i2 = i1 + n2;
|
||||
i3 = i2 + n2;
|
||||
|
||||
/* Butterfly implementation */
|
||||
/* xa + xc */
|
||||
r1 = (pSrc[2u * i0] >> 4u) + (pSrc[2u * i2] >> 4u);
|
||||
/* xa - xc */
|
||||
r2 = (pSrc[2u * i0] >> 4u) - (pSrc[2u * i2] >> 4u);
|
||||
|
||||
/* xb + xd */
|
||||
t1 = (pSrc[2u * i1] >> 4u) + (pSrc[2u * i3] >> 4u);
|
||||
|
||||
/* ya + yc */
|
||||
s1 = (pSrc[(2u * i0) + 1u] >> 4u) + (pSrc[(2u * i2) + 1u] >> 4u);
|
||||
/* ya - yc */
|
||||
s2 = (pSrc[(2u * i0) + 1u] >> 4u) - (pSrc[(2u * i2) + 1u] >> 4u);
|
||||
|
||||
/* xa' = xa + xb + xc + xd */
|
||||
pSrc[2u * i0] = (r1 + t1);
|
||||
/* (xa + xc) - (xb + xd) */
|
||||
r1 = r1 - t1;
|
||||
/* yb + yd */
|
||||
t2 = (pSrc[(2u * i1) + 1u] >> 4u) + (pSrc[(2u * i3) + 1u] >> 4u);
|
||||
/* ya' = ya + yb + yc + yd */
|
||||
pSrc[(2u * i0) + 1u] = (s1 + t2);
|
||||
|
||||
/* (ya + yc) - (yb + yd) */
|
||||
s1 = s1 - t2;
|
||||
|
||||
/* yb - yd */
|
||||
t1 = (pSrc[(2u * i1) + 1u] >> 4u) - (pSrc[(2u * i3) + 1u] >> 4u);
|
||||
/* xb - xd */
|
||||
t2 = (pSrc[2u * i1] >> 4u) - (pSrc[2u * i3] >> 4u);
|
||||
|
||||
/* index calculation for the coefficients */
|
||||
ia2 = 2u * ia1;
|
||||
co2 = pCoef[ia2 * 2u];
|
||||
si2 = pCoef[(ia2 * 2u) + 1u];
|
||||
|
||||
/* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
|
||||
pSrc[2u * i1] = (((int32_t) (((q63_t) r1 * co2) >> 32)) -
|
||||
((int32_t) (((q63_t) s1 * si2) >> 32))) << 1u;
|
||||
|
||||
/* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
|
||||
pSrc[2u * i1 + 1u] = (((int32_t) (((q63_t) s1 * co2) >> 32)) +
|
||||
((int32_t) (((q63_t) r1 * si2) >> 32))) << 1u;
|
||||
|
||||
/* (xa - xc) - (yb - yd) */
|
||||
r1 = r2 - t1;
|
||||
/* (xa - xc) + (yb - yd) */
|
||||
r2 = r2 + t1;
|
||||
|
||||
/* (ya - yc) + (xb - xd) */
|
||||
s1 = s2 + t2;
|
||||
/* (ya - yc) - (xb - xd) */
|
||||
s2 = s2 - t2;
|
||||
|
||||
co1 = pCoef[ia1 * 2u];
|
||||
si1 = pCoef[(ia1 * 2u) + 1u];
|
||||
|
||||
/* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
|
||||
pSrc[2u * i2] = (((int32_t) (((q63_t) r1 * co1) >> 32)) -
|
||||
((int32_t) (((q63_t) s1 * si1) >> 32))) << 1u;
|
||||
|
||||
/* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
|
||||
pSrc[(2u * i2) + 1u] = (((int32_t) (((q63_t) s1 * co1) >> 32)) +
|
||||
((int32_t) (((q63_t) r1 * si1) >> 32))) << 1u;
|
||||
|
||||
/* index calculation for the coefficients */
|
||||
ia3 = 3u * ia1;
|
||||
co3 = pCoef[ia3 * 2u];
|
||||
si3 = pCoef[(ia3 * 2u) + 1u];
|
||||
|
||||
/* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
|
||||
pSrc[2u * i3] = (((int32_t) (((q63_t) r2 * co3) >> 32)) -
|
||||
((int32_t) (((q63_t) s2 * si3) >> 32))) << 1u;
|
||||
|
||||
/* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
|
||||
pSrc[(2u * i3) + 1u] = (((int32_t) (((q63_t) s2 * co3) >> 32)) +
|
||||
((int32_t) (((q63_t) r2 * si3) >> 32))) << 1u;
|
||||
|
||||
/* Twiddle coefficients index modifier */
|
||||
ia1 = ia1 + twidCoefModifier;
|
||||
|
||||
/* Updating input index */
|
||||
i0 = i0 + 1u;
|
||||
|
||||
} while(--j);
|
||||
|
||||
/* data is in 5.27(q27) format */
|
||||
/* each stage provides two down scaling of the input */
|
||||
|
||||
|
||||
/* Start of Middle stages process */
|
||||
|
||||
twidCoefModifier <<= 2u;
|
||||
|
||||
/* Calculation of second stage to excluding last stage */
|
||||
for (k = fftLen / 4u; k > 4u; k >>= 2u)
|
||||
{
|
||||
/* Initializations for the first stage */
|
||||
n1 = n2;
|
||||
n2 >>= 2u;
|
||||
ia1 = 0u;
|
||||
|
||||
for (j = 0; j <= (n2 - 1u); j++)
|
||||
{
|
||||
/* index calculation for the coefficients */
|
||||
ia2 = ia1 + ia1;
|
||||
ia3 = ia2 + ia1;
|
||||
co1 = pCoef[ia1 * 2u];
|
||||
si1 = pCoef[(ia1 * 2u) + 1u];
|
||||
co2 = pCoef[ia2 * 2u];
|
||||
si2 = pCoef[(ia2 * 2u) + 1u];
|
||||
co3 = pCoef[ia3 * 2u];
|
||||
si3 = pCoef[(ia3 * 2u) + 1u];
|
||||
/* Twiddle coefficients index modifier */
|
||||
ia1 = ia1 + twidCoefModifier;
|
||||
|
||||
for (i0 = j; i0 < fftLen; i0 += n1)
|
||||
{
|
||||
/* index calculation for the input as, */
|
||||
/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2u], pSrc[i0 + 3fftLen/4] */
|
||||
i1 = i0 + n2;
|
||||
i2 = i1 + n2;
|
||||
i3 = i2 + n2;
|
||||
|
||||
/* Butterfly implementation */
|
||||
/* xa + xc */
|
||||
r1 = pSrc[2u * i0] + pSrc[2u * i2];
|
||||
/* xa - xc */
|
||||
r2 = pSrc[2u * i0] - pSrc[2u * i2];
|
||||
|
||||
/* ya + yc */
|
||||
s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
|
||||
/* ya - yc */
|
||||
s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
|
||||
|
||||
/* xb + xd */
|
||||
t1 = pSrc[2u * i1] + pSrc[2u * i3];
|
||||
|
||||
/* xa' = xa + xb + xc + xd */
|
||||
pSrc[2u * i0] = (r1 + t1) >> 2u;
|
||||
/* xa + xc -(xb + xd) */
|
||||
r1 = r1 - t1;
|
||||
/* yb + yd */
|
||||
t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
|
||||
/* ya' = ya + yb + yc + yd */
|
||||
pSrc[(2u * i0) + 1u] = (s1 + t2) >> 2u;
|
||||
|
||||
/* (ya + yc) - (yb + yd) */
|
||||
s1 = s1 - t2;
|
||||
|
||||
/* (yb - yd) */
|
||||
t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
|
||||
/* (xb - xd) */
|
||||
t2 = pSrc[2u * i1] - pSrc[2u * i3];
|
||||
|
||||
/* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
|
||||
pSrc[2u * i1] = (((int32_t) (((q63_t) r1 * co2) >> 32u)) -
|
||||
((int32_t) (((q63_t) s1 * si2) >> 32u))) >> 1u;
|
||||
|
||||
/* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
|
||||
pSrc[(2u * i1) + 1u] =
|
||||
(((int32_t) (((q63_t) s1 * co2) >> 32u)) +
|
||||
((int32_t) (((q63_t) r1 * si2) >> 32u))) >> 1u;
|
||||
|
||||
/* (xa - xc) - (yb - yd) */
|
||||
r1 = r2 - t1;
|
||||
/* (xa - xc) + (yb - yd) */
|
||||
r2 = r2 + t1;
|
||||
|
||||
/* (ya - yc) + (xb - xd) */
|
||||
s1 = s2 + t2;
|
||||
/* (ya - yc) - (xb - xd) */
|
||||
s2 = s2 - t2;
|
||||
|
||||
/* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
|
||||
pSrc[2u * i2] = (((int32_t) (((q63_t) r1 * co1) >> 32)) -
|
||||
((int32_t) (((q63_t) s1 * si1) >> 32))) >> 1u;
|
||||
|
||||
/* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
|
||||
pSrc[(2u * i2) + 1u] = (((int32_t) (((q63_t) s1 * co1) >> 32)) +
|
||||
((int32_t) (((q63_t) r1 * si1) >> 32))) >> 1u;
|
||||
|
||||
/* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
|
||||
pSrc[(2u * i3)] = (((int32_t) (((q63_t) r2 * co3) >> 32)) -
|
||||
((int32_t) (((q63_t) s2 * si3) >> 32))) >> 1u;
|
||||
|
||||
/* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
|
||||
pSrc[(2u * i3) + 1u] = (((int32_t) (((q63_t) s2 * co3) >> 32)) +
|
||||
((int32_t) (((q63_t) r2 * si3) >> 32))) >> 1u;
|
||||
}
|
||||
}
|
||||
twidCoefModifier <<= 2u;
|
||||
}
|
||||
|
||||
/* End of Middle stages process */
|
||||
|
||||
/* data is in 11.21(q21) format for the 1024 point as there are 3 middle stages */
|
||||
/* data is in 9.23(q23) format for the 256 point as there are 2 middle stages */
|
||||
/* data is in 7.25(q25) format for the 64 point as there are 1 middle stage */
|
||||
/* data is in 5.27(q27) format for the 16 point as there are no middle stages */
|
||||
|
||||
|
||||
/* Start of last stage process */
|
||||
|
||||
|
||||
/* Initializations for the last stage */
|
||||
j = fftLen >> 2;
|
||||
ptr1 = &pSrc[0];
|
||||
|
||||
/* Calculations of last stage */
|
||||
do
|
||||
{
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
/* Read xa (real), ya(imag) input */
|
||||
xaya = *__SIMD64(ptr1)++;
|
||||
xa = (q31_t) xaya;
|
||||
ya = (q31_t) (xaya >> 32);
|
||||
|
||||
/* Read xb (real), yb(imag) input */
|
||||
xbyb = *__SIMD64(ptr1)++;
|
||||
xb = (q31_t) xbyb;
|
||||
yb = (q31_t) (xbyb >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xcyc = *__SIMD64(ptr1)++;
|
||||
xc = (q31_t) xcyc;
|
||||
yc = (q31_t) (xcyc >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xdyd = *__SIMD64(ptr1)++;
|
||||
xd = (q31_t) xdyd;
|
||||
yd = (q31_t) (xdyd >> 32);
|
||||
|
||||
#else
|
||||
|
||||
/* Read xa (real), ya(imag) input */
|
||||
xaya = *__SIMD64(ptr1)++;
|
||||
ya = (q31_t) xaya;
|
||||
xa = (q31_t) (xaya >> 32);
|
||||
|
||||
/* Read xb (real), yb(imag) input */
|
||||
xbyb = *__SIMD64(ptr1)++;
|
||||
yb = (q31_t) xbyb;
|
||||
xb = (q31_t) (xbyb >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xcyc = *__SIMD64(ptr1)++;
|
||||
yc = (q31_t) xcyc;
|
||||
xc = (q31_t) (xcyc >> 32);
|
||||
|
||||
/* Read xc (real), yc(imag) input */
|
||||
xdyd = *__SIMD64(ptr1)++;
|
||||
yd = (q31_t) xdyd;
|
||||
xd = (q31_t) (xdyd >> 32);
|
||||
|
||||
|
||||
#endif
|
||||
|
||||
/* xa' = xa + xb + xc + xd */
|
||||
xa_out = xa + xb + xc + xd;
|
||||
|
||||
/* ya' = ya + yb + yc + yd */
|
||||
ya_out = ya + yb + yc + yd;
|
||||
|
||||
/* pointer updation for writing */
|
||||
ptr1 = ptr1 - 8u;
|
||||
|
||||
/* writing xa' and ya' */
|
||||
*ptr1++ = xa_out;
|
||||
*ptr1++ = ya_out;
|
||||
|
||||
xc_out = (xa - xb + xc - xd);
|
||||
yc_out = (ya - yb + yc - yd);
|
||||
|
||||
/* writing xc' and yc' */
|
||||
*ptr1++ = xc_out;
|
||||
*ptr1++ = yc_out;
|
||||
|
||||
xb_out = (xa - yb - xc + yd);
|
||||
yb_out = (ya + xb - yc - xd);
|
||||
|
||||
/* writing xb' and yb' */
|
||||
*ptr1++ = xb_out;
|
||||
*ptr1++ = yb_out;
|
||||
|
||||
xd_out = (xa + yb - xc - yd);
|
||||
yd_out = (ya - xb - yc + xd);
|
||||
|
||||
/* writing xd' and yd' */
|
||||
*ptr1++ = xd_out;
|
||||
*ptr1++ = yd_out;
|
||||
|
||||
|
||||
} while(--j);
|
||||
|
||||
/* output is in 11.21(q21) format for the 1024 point */
|
||||
/* output is in 9.23(q23) format for the 256 point */
|
||||
/* output is in 7.25(q25) format for the 64 point */
|
||||
/* output is in 5.27(q27) format for the 16 point */
|
||||
|
||||
/* End of last stage process */
|
||||
}
|
@ -0,0 +1,384 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_radix8_f32.c
|
||||
*
|
||||
* Description: Radix-8 Decimation in Frequency CFFT & CIFFT Floating point processing function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @defgroup Radix8_CFFT_CIFFT Radix-8 Complex FFT Functions
|
||||
*
|
||||
* \par
|
||||
* Complex Fast Fourier Transform(CFFT) and Complex Inverse Fast Fourier Transform(CIFFT) is an efficient algorithm to compute Discrete Fourier Transform(DFT) and Inverse Discrete Fourier Transform(IDFT).
|
||||
* Computational complexity of CFFT reduces drastically when compared to DFT.
|
||||
* \par
|
||||
* This set of functions implements CFFT/CIFFT
|
||||
* for floating-point data types. The functions operates on in-place buffer which uses same buffer for input and output.
|
||||
* Complex input is stored in input buffer in an interleaved fashion.
|
||||
*
|
||||
* \par
|
||||
* The functions operate on blocks of input and output data and each call to the function processes
|
||||
* <code>2*fftLen</code> samples through the transform. <code>pSrc</code> points to In-place arrays containing <code>2*fftLen</code> values.
|
||||
* \par
|
||||
* The <code>pSrc</code> points to the array of in-place buffer of size <code>2*fftLen</code> and inputs and outputs are stored in an interleaved fashion as shown below.
|
||||
* <pre> {real[0], imag[0], real[1], imag[1],..} </pre>
|
||||
*
|
||||
* \par Lengths supported by the transform:
|
||||
* \par
|
||||
* Internally, the function utilize a Radix-8 decimation in frequency(DIF) algorithm
|
||||
* and the size of the FFT supported are of the lengths [ 64, 512, 4096].
|
||||
*
|
||||
*
|
||||
* \par Algorithm:
|
||||
*
|
||||
* <b>Complex Fast Fourier Transform:</b>
|
||||
* \par
|
||||
* Input real and imaginary data:
|
||||
* <pre>
|
||||
* x(n) = xa + j * ya
|
||||
* x(n+N/4 ) = xb + j * yb
|
||||
* x(n+N/2 ) = xc + j * yc
|
||||
* x(n+3N 4) = xd + j * yd
|
||||
* </pre>
|
||||
* where N is length of FFT
|
||||
* \par
|
||||
* Output real and imaginary data:
|
||||
* <pre>
|
||||
* X(4r) = xa'+ j * ya'
|
||||
* X(4r+1) = xb'+ j * yb'
|
||||
* X(4r+2) = xc'+ j * yc'
|
||||
* X(4r+3) = xd'+ j * yd'
|
||||
* </pre>
|
||||
* \par
|
||||
* Twiddle factors for Radix-8 FFT:
|
||||
* <pre>
|
||||
* Wn = co1 + j * (- si1)
|
||||
* W2n = co2 + j * (- si2)
|
||||
* W3n = co3 + j * (- si3)
|
||||
* </pre>
|
||||
*
|
||||
* \par
|
||||
* \image html CFFT.gif "Radix-8 Decimation-in Frequency Complex Fast Fourier Transform"
|
||||
*
|
||||
* \par
|
||||
* Output from Radix-8 CFFT Results in Digit reversal order. Interchange middle two branches of every butterfly results in Bit reversed output.
|
||||
* \par
|
||||
* <b> Butterfly CFFT equations:</b>
|
||||
* <pre>
|
||||
* xa' = xa + xb + xc + xd
|
||||
* ya' = ya + yb + yc + yd
|
||||
* xc' = (xa+yb-xc-yd)* co1 + (ya-xb-yc+xd)* (si1)
|
||||
* yc' = (ya-xb-yc+xd)* co1 - (xa+yb-xc-yd)* (si1)
|
||||
* xb' = (xa-xb+xc-xd)* co2 + (ya-yb+yc-yd)* (si2)
|
||||
* yb' = (ya-yb+yc-yd)* co2 - (xa-xb+xc-xd)* (si2)
|
||||
* xd' = (xa-yb-xc+yd)* co3 + (ya+xb-yc-xd)* (si3)
|
||||
* yd' = (ya+xb-yc-xd)* co3 - (xa-yb-xc+yd)* (si3)
|
||||
* </pre>
|
||||
*
|
||||
* \par
|
||||
* where <code>fftLen</code> length of CFFT/CIFFT; <code>ifftFlag</code> Flag for selection of CFFT or CIFFT(Set ifftFlag to calculate CIFFT otherwise calculates CFFT);
|
||||
* <code>bitReverseFlag</code> Flag for selection of output order(Set bitReverseFlag to output in normal order otherwise output in bit reversed order);
|
||||
* <code>pTwiddle</code>points to array of twiddle coefficients; <code>pBitRevTable</code> points to the array of bit reversal table.
|
||||
* <code>twidCoefModifier</code> modifier for twiddle factor table which supports all FFT lengths with same table;
|
||||
* <code>pBitRevTable</code> modifier for bit reversal table which supports all FFT lengths with same table.
|
||||
* <code>onebyfftLen</code> value of 1/fftLen to calculate CIFFT;
|
||||
*
|
||||
* \par Fixed-Point Behavior
|
||||
* Care must be taken when using the fixed-point versions of the CFFT/CIFFT function.
|
||||
* Refer to the function specific documentation below for usage guidelines.
|
||||
*/
|
||||
|
||||
|
||||
/*
|
||||
* @brief Core function for the floating-point CFFT butterfly process.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
|
||||
* @param[in] fftLen length of the FFT.
|
||||
* @param[in] *pCoef points to the twiddle coefficient buffer.
|
||||
* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_radix8_butterfly_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftLen,
|
||||
const float32_t * pCoef,
|
||||
uint16_t twidCoefModifier)
|
||||
{
|
||||
uint32_t ia1, ia2, ia3, ia4, ia5, ia6, ia7;
|
||||
uint32_t i1, i2, i3, i4, i5, i6, i7, i8;
|
||||
uint32_t id;
|
||||
uint32_t n1, n2, j;
|
||||
|
||||
float32_t r1, r2, r3, r4, r5, r6, r7, r8;
|
||||
float32_t t1, t2;
|
||||
float32_t s1, s2, s3, s4, s5, s6, s7, s8;
|
||||
float32_t p1, p2, p3, p4;
|
||||
float32_t co2, co3, co4, co5, co6, co7, co8;
|
||||
float32_t si2, si3, si4, si5, si6, si7, si8;
|
||||
const float32_t C81 = 0.70710678118f;
|
||||
|
||||
n2 = fftLen;
|
||||
|
||||
do
|
||||
{
|
||||
n1 = n2;
|
||||
n2 = n2 >> 3;
|
||||
i1 = 0;
|
||||
|
||||
do
|
||||
{
|
||||
i2 = i1 + n2;
|
||||
i3 = i2 + n2;
|
||||
i4 = i3 + n2;
|
||||
i5 = i4 + n2;
|
||||
i6 = i5 + n2;
|
||||
i7 = i6 + n2;
|
||||
i8 = i7 + n2;
|
||||
r1 = pSrc[2 * i1] + pSrc[2 * i5];
|
||||
r5 = pSrc[2 * i1] - pSrc[2 * i5];
|
||||
r2 = pSrc[2 * i2] + pSrc[2 * i6];
|
||||
r6 = pSrc[2 * i2] - pSrc[2 * i6];
|
||||
r3 = pSrc[2 * i3] + pSrc[2 * i7];
|
||||
r7 = pSrc[2 * i3] - pSrc[2 * i7];
|
||||
r4 = pSrc[2 * i4] + pSrc[2 * i8];
|
||||
r8 = pSrc[2 * i4] - pSrc[2 * i8];
|
||||
t1 = r1 - r3;
|
||||
r1 = r1 + r3;
|
||||
r3 = r2 - r4;
|
||||
r2 = r2 + r4;
|
||||
pSrc[2 * i1] = r1 + r2;
|
||||
pSrc[2 * i5] = r1 - r2;
|
||||
r1 = pSrc[2 * i1 + 1] + pSrc[2 * i5 + 1];
|
||||
s5 = pSrc[2 * i1 + 1] - pSrc[2 * i5 + 1];
|
||||
r2 = pSrc[2 * i2 + 1] + pSrc[2 * i6 + 1];
|
||||
s6 = pSrc[2 * i2 + 1] - pSrc[2 * i6 + 1];
|
||||
s3 = pSrc[2 * i3 + 1] + pSrc[2 * i7 + 1];
|
||||
s7 = pSrc[2 * i3 + 1] - pSrc[2 * i7 + 1];
|
||||
r4 = pSrc[2 * i4 + 1] + pSrc[2 * i8 + 1];
|
||||
s8 = pSrc[2 * i4 + 1] - pSrc[2 * i8 + 1];
|
||||
t2 = r1 - s3;
|
||||
r1 = r1 + s3;
|
||||
s3 = r2 - r4;
|
||||
r2 = r2 + r4;
|
||||
pSrc[2 * i1 + 1] = r1 + r2;
|
||||
pSrc[2 * i5 + 1] = r1 - r2;
|
||||
pSrc[2 * i3] = t1 + s3;
|
||||
pSrc[2 * i7] = t1 - s3;
|
||||
pSrc[2 * i3 + 1] = t2 - r3;
|
||||
pSrc[2 * i7 + 1] = t2 + r3;
|
||||
r1 = (r6 - r8) * C81;
|
||||
r6 = (r6 + r8) * C81;
|
||||
r2 = (s6 - s8) * C81;
|
||||
s6 = (s6 + s8) * C81;
|
||||
t1 = r5 - r1;
|
||||
r5 = r5 + r1;
|
||||
r8 = r7 - r6;
|
||||
r7 = r7 + r6;
|
||||
t2 = s5 - r2;
|
||||
s5 = s5 + r2;
|
||||
s8 = s7 - s6;
|
||||
s7 = s7 + s6;
|
||||
pSrc[2 * i2] = r5 + s7;
|
||||
pSrc[2 * i8] = r5 - s7;
|
||||
pSrc[2 * i6] = t1 + s8;
|
||||
pSrc[2 * i4] = t1 - s8;
|
||||
pSrc[2 * i2 + 1] = s5 - r7;
|
||||
pSrc[2 * i8 + 1] = s5 + r7;
|
||||
pSrc[2 * i6 + 1] = t2 - r8;
|
||||
pSrc[2 * i4 + 1] = t2 + r8;
|
||||
|
||||
i1 += n1;
|
||||
} while(i1 < fftLen);
|
||||
|
||||
if(n2 < 8)
|
||||
break;
|
||||
|
||||
ia1 = 0;
|
||||
j = 1;
|
||||
|
||||
do
|
||||
{
|
||||
/* index calculation for the coefficients */
|
||||
id = ia1 + twidCoefModifier;
|
||||
ia1 = id;
|
||||
ia2 = ia1 + id;
|
||||
ia3 = ia2 + id;
|
||||
ia4 = ia3 + id;
|
||||
ia5 = ia4 + id;
|
||||
ia6 = ia5 + id;
|
||||
ia7 = ia6 + id;
|
||||
|
||||
co2 = pCoef[2 * ia1];
|
||||
co3 = pCoef[2 * ia2];
|
||||
co4 = pCoef[2 * ia3];
|
||||
co5 = pCoef[2 * ia4];
|
||||
co6 = pCoef[2 * ia5];
|
||||
co7 = pCoef[2 * ia6];
|
||||
co8 = pCoef[2 * ia7];
|
||||
si2 = pCoef[2 * ia1 + 1];
|
||||
si3 = pCoef[2 * ia2 + 1];
|
||||
si4 = pCoef[2 * ia3 + 1];
|
||||
si5 = pCoef[2 * ia4 + 1];
|
||||
si6 = pCoef[2 * ia5 + 1];
|
||||
si7 = pCoef[2 * ia6 + 1];
|
||||
si8 = pCoef[2 * ia7 + 1];
|
||||
|
||||
i1 = j;
|
||||
|
||||
do
|
||||
{
|
||||
/* index calculation for the input */
|
||||
i2 = i1 + n2;
|
||||
i3 = i2 + n2;
|
||||
i4 = i3 + n2;
|
||||
i5 = i4 + n2;
|
||||
i6 = i5 + n2;
|
||||
i7 = i6 + n2;
|
||||
i8 = i7 + n2;
|
||||
r1 = pSrc[2 * i1] + pSrc[2 * i5];
|
||||
r5 = pSrc[2 * i1] - pSrc[2 * i5];
|
||||
r2 = pSrc[2 * i2] + pSrc[2 * i6];
|
||||
r6 = pSrc[2 * i2] - pSrc[2 * i6];
|
||||
r3 = pSrc[2 * i3] + pSrc[2 * i7];
|
||||
r7 = pSrc[2 * i3] - pSrc[2 * i7];
|
||||
r4 = pSrc[2 * i4] + pSrc[2 * i8];
|
||||
r8 = pSrc[2 * i4] - pSrc[2 * i8];
|
||||
t1 = r1 - r3;
|
||||
r1 = r1 + r3;
|
||||
r3 = r2 - r4;
|
||||
r2 = r2 + r4;
|
||||
pSrc[2 * i1] = r1 + r2;
|
||||
r2 = r1 - r2;
|
||||
s1 = pSrc[2 * i1 + 1] + pSrc[2 * i5 + 1];
|
||||
s5 = pSrc[2 * i1 + 1] - pSrc[2 * i5 + 1];
|
||||
s2 = pSrc[2 * i2 + 1] + pSrc[2 * i6 + 1];
|
||||
s6 = pSrc[2 * i2 + 1] - pSrc[2 * i6 + 1];
|
||||
s3 = pSrc[2 * i3 + 1] + pSrc[2 * i7 + 1];
|
||||
s7 = pSrc[2 * i3 + 1] - pSrc[2 * i7 + 1];
|
||||
s4 = pSrc[2 * i4 + 1] + pSrc[2 * i8 + 1];
|
||||
s8 = pSrc[2 * i4 + 1] - pSrc[2 * i8 + 1];
|
||||
t2 = s1 - s3;
|
||||
s1 = s1 + s3;
|
||||
s3 = s2 - s4;
|
||||
s2 = s2 + s4;
|
||||
r1 = t1 + s3;
|
||||
t1 = t1 - s3;
|
||||
pSrc[2 * i1 + 1] = s1 + s2;
|
||||
s2 = s1 - s2;
|
||||
s1 = t2 - r3;
|
||||
t2 = t2 + r3;
|
||||
p1 = co5 * r2;
|
||||
p2 = si5 * s2;
|
||||
p3 = co5 * s2;
|
||||
p4 = si5 * r2;
|
||||
pSrc[2 * i5] = p1 + p2;
|
||||
pSrc[2 * i5 + 1] = p3 - p4;
|
||||
p1 = co3 * r1;
|
||||
p2 = si3 * s1;
|
||||
p3 = co3 * s1;
|
||||
p4 = si3 * r1;
|
||||
pSrc[2 * i3] = p1 + p2;
|
||||
pSrc[2 * i3 + 1] = p3 - p4;
|
||||
p1 = co7 * t1;
|
||||
p2 = si7 * t2;
|
||||
p3 = co7 * t2;
|
||||
p4 = si7 * t1;
|
||||
pSrc[2 * i7] = p1 + p2;
|
||||
pSrc[2 * i7 + 1] = p3 - p4;
|
||||
r1 = (r6 - r8) * C81;
|
||||
r6 = (r6 + r8) * C81;
|
||||
s1 = (s6 - s8) * C81;
|
||||
s6 = (s6 + s8) * C81;
|
||||
t1 = r5 - r1;
|
||||
r5 = r5 + r1;
|
||||
r8 = r7 - r6;
|
||||
r7 = r7 + r6;
|
||||
t2 = s5 - s1;
|
||||
s5 = s5 + s1;
|
||||
s8 = s7 - s6;
|
||||
s7 = s7 + s6;
|
||||
r1 = r5 + s7;
|
||||
r5 = r5 - s7;
|
||||
r6 = t1 + s8;
|
||||
t1 = t1 - s8;
|
||||
s1 = s5 - r7;
|
||||
s5 = s5 + r7;
|
||||
s6 = t2 - r8;
|
||||
t2 = t2 + r8;
|
||||
p1 = co2 * r1;
|
||||
p2 = si2 * s1;
|
||||
p3 = co2 * s1;
|
||||
p4 = si2 * r1;
|
||||
pSrc[2 * i2] = p1 + p2;
|
||||
pSrc[2 * i2 + 1] = p3 - p4;
|
||||
p1 = co8 * r5;
|
||||
p2 = si8 * s5;
|
||||
p3 = co8 * s5;
|
||||
p4 = si8 * r5;
|
||||
pSrc[2 * i8] = p1 + p2;
|
||||
pSrc[2 * i8 + 1] = p3 - p4;
|
||||
p1 = co6 * r6;
|
||||
p2 = si6 * s6;
|
||||
p3 = co6 * s6;
|
||||
p4 = si6 * r6;
|
||||
pSrc[2 * i6] = p1 + p2;
|
||||
pSrc[2 * i6 + 1] = p3 - p4;
|
||||
p1 = co4 * t1;
|
||||
p2 = si4 * t2;
|
||||
p3 = co4 * t2;
|
||||
p4 = si4 * t1;
|
||||
pSrc[2 * i4] = p1 + p2;
|
||||
pSrc[2 * i4 + 1] = p3 - p4;
|
||||
|
||||
i1 += n1;
|
||||
} while(i1 < fftLen);
|
||||
|
||||
j++;
|
||||
} while(j < n2);
|
||||
|
||||
twidCoefModifier <<= 3;
|
||||
} while(n2 > 7);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of Radix8_CFFT_CIFFT group
|
||||
*/
|
@ -0,0 +1,461 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_dct4_f32.c
|
||||
*
|
||||
* Description: Processing function of DCT4 & IDCT4 F32.
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @defgroup DCT4_IDCT4 DCT Type IV Functions
|
||||
* Representation of signals by minimum number of values is important for storage and transmission.
|
||||
* The possibility of large discontinuity between the beginning and end of a period of a signal
|
||||
* in DFT can be avoided by extending the signal so that it is even-symmetric.
|
||||
* Discrete Cosine Transform (DCT) is constructed such that its energy is heavily concentrated in the lower part of the
|
||||
* spectrum and is very widely used in signal and image coding applications.
|
||||
* The family of DCTs (DCT type- 1,2,3,4) is the outcome of different combinations of homogeneous boundary conditions.
|
||||
* DCT has an excellent energy-packing capability, hence has many applications and in data compression in particular.
|
||||
*
|
||||
* DCT is essentially the Discrete Fourier Transform(DFT) of an even-extended real signal.
|
||||
* Reordering of the input data makes the computation of DCT just a problem of
|
||||
* computing the DFT of a real signal with a few additional operations.
|
||||
* This approach provides regular, simple, and very efficient DCT algorithms for practical hardware and software implementations.
|
||||
*
|
||||
* DCT type-II can be implemented using Fast fourier transform (FFT) internally, as the transform is applied on real values, Real FFT can be used.
|
||||
* DCT4 is implemented using DCT2 as their implementations are similar except with some added pre-processing and post-processing.
|
||||
* DCT2 implementation can be described in the following steps:
|
||||
* - Re-ordering input
|
||||
* - Calculating Real FFT
|
||||
* - Multiplication of weights and Real FFT output and getting real part from the product.
|
||||
*
|
||||
* This process is explained by the block diagram below:
|
||||
* \image html DCT4.gif "Discrete Cosine Transform - type-IV"
|
||||
*
|
||||
* \par Algorithm:
|
||||
* The N-point type-IV DCT is defined as a real, linear transformation by the formula:
|
||||
* \image html DCT4Equation.gif
|
||||
* where <code>k = 0,1,2,.....N-1</code>
|
||||
*\par
|
||||
* Its inverse is defined as follows:
|
||||
* \image html IDCT4Equation.gif
|
||||
* where <code>n = 0,1,2,.....N-1</code>
|
||||
*\par
|
||||
* The DCT4 matrices become involutory (i.e. they are self-inverse) by multiplying with an overall scale factor of sqrt(2/N).
|
||||
* The symmetry of the transform matrix indicates that the fast algorithms for the forward
|
||||
* and inverse transform computation are identical.
|
||||
* Note that the implementation of Inverse DCT4 and DCT4 is same, hence same process function can be used for both.
|
||||
*
|
||||
* \par Lengths supported by the transform:
|
||||
* As DCT4 internally uses Real FFT, it supports all the lengths supported by arm_rfft_f32().
|
||||
* The library provides separate functions for Q15, Q31, and floating-point data types.
|
||||
* \par Instance Structure
|
||||
* The instances for Real FFT and FFT, cosine values table and twiddle factor table are stored in an instance data structure.
|
||||
* A separate instance structure must be defined for each transform.
|
||||
* There are separate instance structure declarations for each of the 3 supported data types.
|
||||
*
|
||||
* \par Initialization Functions
|
||||
* There is also an associated initialization function for each data type.
|
||||
* The initialization function performs the following operations:
|
||||
* - Sets the values of the internal structure fields.
|
||||
* - Initializes Real FFT as its process function is used internally in DCT4, by calling arm_rfft_init_f32().
|
||||
* \par
|
||||
* Use of the initialization function is optional.
|
||||
* However, if the initialization function is used, then the instance structure cannot be placed into a const data section.
|
||||
* To place an instance structure into a const data section, the instance structure must be manually initialized.
|
||||
* Manually initialize the instance structure as follows:
|
||||
* <pre>
|
||||
*arm_dct4_instance_f32 S = {N, Nby2, normalize, pTwiddle, pCosFactor, pRfft, pCfft};
|
||||
*arm_dct4_instance_q31 S = {N, Nby2, normalize, pTwiddle, pCosFactor, pRfft, pCfft};
|
||||
*arm_dct4_instance_q15 S = {N, Nby2, normalize, pTwiddle, pCosFactor, pRfft, pCfft};
|
||||
* </pre>
|
||||
* where \c N is the length of the DCT4; \c Nby2 is half of the length of the DCT4;
|
||||
* \c normalize is normalizing factor used and is equal to <code>sqrt(2/N)</code>;
|
||||
* \c pTwiddle points to the twiddle factor table;
|
||||
* \c pCosFactor points to the cosFactor table;
|
||||
* \c pRfft points to the real FFT instance;
|
||||
* \c pCfft points to the complex FFT instance;
|
||||
* The CFFT and RFFT structures also needs to be initialized, refer to arm_cfft_radix4_f32()
|
||||
* and arm_rfft_f32() respectively for details regarding static initialization.
|
||||
*
|
||||
* \par Fixed-Point Behavior
|
||||
* Care must be taken when using the fixed-point versions of the DCT4 transform functions.
|
||||
* In particular, the overflow and saturation behavior of the accumulator used in each function must be considered.
|
||||
* Refer to the function specific documentation below for usage guidelines.
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup DCT4_IDCT4
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the floating-point DCT4/IDCT4.
|
||||
* @param[in] *S points to an instance of the floating-point DCT4/IDCT4 structure.
|
||||
* @param[in] *pState points to state buffer.
|
||||
* @param[in,out] *pInlineBuffer points to the in-place input and output buffer.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_dct4_f32(
|
||||
const arm_dct4_instance_f32 * S,
|
||||
float32_t * pState,
|
||||
float32_t * pInlineBuffer)
|
||||
{
|
||||
uint32_t i; /* Loop counter */
|
||||
float32_t *weights = S->pTwiddle; /* Pointer to the Weights table */
|
||||
float32_t *cosFact = S->pCosFactor; /* Pointer to the cos factors table */
|
||||
float32_t *pS1, *pS2, *pbuff; /* Temporary pointers for input buffer and pState buffer */
|
||||
float32_t in; /* Temporary variable */
|
||||
|
||||
|
||||
/* DCT4 computation involves DCT2 (which is calculated using RFFT)
|
||||
* along with some pre-processing and post-processing.
|
||||
* Computational procedure is explained as follows:
|
||||
* (a) Pre-processing involves multiplying input with cos factor,
|
||||
* r(n) = 2 * u(n) * cos(pi*(2*n+1)/(4*n))
|
||||
* where,
|
||||
* r(n) -- output of preprocessing
|
||||
* u(n) -- input to preprocessing(actual Source buffer)
|
||||
* (b) Calculation of DCT2 using FFT is divided into three steps:
|
||||
* Step1: Re-ordering of even and odd elements of input.
|
||||
* Step2: Calculating FFT of the re-ordered input.
|
||||
* Step3: Taking the real part of the product of FFT output and weights.
|
||||
* (c) Post-processing - DCT4 can be obtained from DCT2 output using the following equation:
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* where,
|
||||
* Y4 -- DCT4 output, Y2 -- DCT2 output
|
||||
* (d) Multiplying the output with the normalizing factor sqrt(2/N).
|
||||
*/
|
||||
|
||||
/*-------- Pre-processing ------------*/
|
||||
/* Multiplying input with cos factor i.e. r(n) = 2 * x(n) * cos(pi*(2*n+1)/(4*n)) */
|
||||
arm_scale_f32(pInlineBuffer, 2.0f, pInlineBuffer, S->N);
|
||||
arm_mult_f32(pInlineBuffer, cosFact, pInlineBuffer, S->N);
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* Step1: Re-ordering of even and odd elements as,
|
||||
* pState[i] = pInlineBuffer[2*i] and
|
||||
* pState[N-i-1] = pInlineBuffer[2*i+1] where i = 0 to N/2
|
||||
---------------------------------------------------------------------*/
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* pS2 initialized to pState+N-1, so that it points to the end of the state buffer */
|
||||
pS2 = pState + (S->N - 1u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
||||
|
||||
/* Initializing the loop counter to N/2 >> 2 for loop unrolling by 4 */
|
||||
i = (uint32_t) S->Nby2 >> 2u;
|
||||
|
||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
||||
** a second loop below computes the remaining 1 to 3 samples. */
|
||||
do
|
||||
{
|
||||
/* Re-ordering of even and odd elements */
|
||||
/* pState[i] = pInlineBuffer[2*i] */
|
||||
*pS1++ = *pbuff++;
|
||||
/* pState[N-i-1] = pInlineBuffer[2*i+1] */
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Initializing the loop counter to N/4 instead of N for loop unrolling */
|
||||
i = (uint32_t) S->N >> 2u;
|
||||
|
||||
/* Processing with loop unrolling 4 times as N is always multiple of 4.
|
||||
* Compute 4 outputs at a time */
|
||||
do
|
||||
{
|
||||
/* Writing the re-ordered output back to inplace input buffer */
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/* ---------------------------------------------------------
|
||||
* Step2: Calculate RFFT for N-point input
|
||||
* ---------------------------------------------------------- */
|
||||
/* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
|
||||
arm_rfft_f32(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_f32(pState, weights, pState, S->N);
|
||||
|
||||
/* ----------- Post-processing ---------- */
|
||||
/* DCT-IV can be obtained from DCT-II by the equation,
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* Hence, Y4(0) = Y2(0)/2 */
|
||||
/* Getting only real part from the output and Converting to DCT-IV */
|
||||
|
||||
/* Initializing the loop counter to N >> 2 for loop unrolling by 4 */
|
||||
i = ((uint32_t) S->N - 1u) >> 2u;
|
||||
|
||||
/* pbuff initialized to input buffer. */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
|
||||
in = *pS1++ * (float32_t) 0.5;
|
||||
/* input buffer acts as inplace, so output values are stored in the input itself. */
|
||||
*pbuff++ = in;
|
||||
|
||||
/* pState pointer is incremented twice as the real values are located alternatively in the array */
|
||||
pS1++;
|
||||
|
||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
||||
** a second loop below computes the remaining 1 to 3 samples. */
|
||||
do
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
|
||||
** No loop unrolling is used. */
|
||||
i = ((uint32_t) S->N - 1u) % 0x4u;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
}
|
||||
|
||||
|
||||
/*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
|
||||
|
||||
/* Initializing the loop counter to N/4 instead of N for loop unrolling */
|
||||
i = (uint32_t) S->N >> 2u;
|
||||
|
||||
/* pbuff initialized to the pInlineBuffer(now contains the output values) */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* Processing with loop unrolling 4 times as N is always multiple of 4. Compute 4 outputs at a time */
|
||||
do
|
||||
{
|
||||
/* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
|
||||
in = *pbuff;
|
||||
*pbuff++ = in * S->normalize;
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = in * S->normalize;
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = in * S->normalize;
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = in * S->normalize;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
#else
|
||||
|
||||
/* Run the below code for Cortex-M0 */
|
||||
|
||||
/* Initializing the loop counter to N/2 */
|
||||
i = (uint32_t) S->Nby2;
|
||||
|
||||
do
|
||||
{
|
||||
/* Re-ordering of even and odd elements */
|
||||
/* pState[i] = pInlineBuffer[2*i] */
|
||||
*pS1++ = *pbuff++;
|
||||
/* pState[N-i-1] = pInlineBuffer[2*i+1] */
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = (uint32_t) S->N;
|
||||
|
||||
do
|
||||
{
|
||||
/* Writing the re-ordered output back to inplace input buffer */
|
||||
*pbuff++ = *pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/* ---------------------------------------------------------
|
||||
* Step2: Calculate RFFT for N-point input
|
||||
* ---------------------------------------------------------- */
|
||||
/* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
|
||||
arm_rfft_f32(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_f32(pState, weights, pState, S->N);
|
||||
|
||||
/* ----------- Post-processing ---------- */
|
||||
/* DCT-IV can be obtained from DCT-II by the equation,
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* Hence, Y4(0) = Y2(0)/2 */
|
||||
/* Getting only real part from the output and Converting to DCT-IV */
|
||||
|
||||
/* pbuff initialized to input buffer. */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
|
||||
in = *pS1++ * (float32_t) 0.5;
|
||||
/* input buffer acts as inplace, so output values are stored in the input itself. */
|
||||
*pbuff++ = in;
|
||||
|
||||
/* pState pointer is incremented twice as the real values are located alternatively in the array */
|
||||
pS1++;
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = ((uint32_t) S->N - 1u);
|
||||
|
||||
do
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = (uint32_t) S->N;
|
||||
|
||||
/* pbuff initialized to the pInlineBuffer(now contains the output values) */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
do
|
||||
{
|
||||
/* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
|
||||
in = *pbuff;
|
||||
*pbuff++ = in * S->normalize;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of DCT4_IDCT4 group
|
||||
*/
|
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
@ -0,0 +1,394 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_dct4_q15.c
|
||||
*
|
||||
* Description: Processing function of DCT4 & IDCT4 Q15.
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
/**
|
||||
* @addtogroup DCT4_IDCT4
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the Q15 DCT4/IDCT4.
|
||||
* @param[in] *S points to an instance of the Q15 DCT4 structure.
|
||||
* @param[in] *pState points to state buffer.
|
||||
* @param[in,out] *pInlineBuffer points to the in-place input and output buffer.
|
||||
* @return none.
|
||||
*
|
||||
* \par Input an output formats:
|
||||
* Internally inputs are downscaled in the RFFT process function to avoid overflows.
|
||||
* Number of bits downscaled, depends on the size of the transform.
|
||||
* The input and output formats for different DCT sizes and number of bits to upscale are mentioned in the table below:
|
||||
*
|
||||
* \image html dct4FormatsQ15Table.gif
|
||||
*/
|
||||
|
||||
void arm_dct4_q15(
|
||||
const arm_dct4_instance_q15 * S,
|
||||
q15_t * pState,
|
||||
q15_t * pInlineBuffer)
|
||||
{
|
||||
uint32_t i; /* Loop counter */
|
||||
q15_t *weights = S->pTwiddle; /* Pointer to the Weights table */
|
||||
q15_t *cosFact = S->pCosFactor; /* Pointer to the cos factors table */
|
||||
q15_t *pS1, *pS2, *pbuff; /* Temporary pointers for input buffer and pState buffer */
|
||||
q15_t in; /* Temporary variable */
|
||||
|
||||
|
||||
/* DCT4 computation involves DCT2 (which is calculated using RFFT)
|
||||
* along with some pre-processing and post-processing.
|
||||
* Computational procedure is explained as follows:
|
||||
* (a) Pre-processing involves multiplying input with cos factor,
|
||||
* r(n) = 2 * u(n) * cos(pi*(2*n+1)/(4*n))
|
||||
* where,
|
||||
* r(n) -- output of preprocessing
|
||||
* u(n) -- input to preprocessing(actual Source buffer)
|
||||
* (b) Calculation of DCT2 using FFT is divided into three steps:
|
||||
* Step1: Re-ordering of even and odd elements of input.
|
||||
* Step2: Calculating FFT of the re-ordered input.
|
||||
* Step3: Taking the real part of the product of FFT output and weights.
|
||||
* (c) Post-processing - DCT4 can be obtained from DCT2 output using the following equation:
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* where,
|
||||
* Y4 -- DCT4 output, Y2 -- DCT2 output
|
||||
* (d) Multiplying the output with the normalizing factor sqrt(2/N).
|
||||
*/
|
||||
|
||||
/*-------- Pre-processing ------------*/
|
||||
/* Multiplying input with cos factor i.e. r(n) = 2 * x(n) * cos(pi*(2*n+1)/(4*n)) */
|
||||
arm_mult_q15(pInlineBuffer, cosFact, pInlineBuffer, S->N);
|
||||
arm_shift_q15(pInlineBuffer, 1, pInlineBuffer, S->N);
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* Step1: Re-ordering of even and odd elements as
|
||||
* pState[i] = pInlineBuffer[2*i] and
|
||||
* pState[N-i-1] = pInlineBuffer[2*i+1] where i = 0 to N/2
|
||||
---------------------------------------------------------------------*/
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* pS2 initialized to pState+N-1, so that it points to the end of the state buffer */
|
||||
pS2 = pState + (S->N - 1u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
||||
|
||||
/* Initializing the loop counter to N/2 >> 2 for loop unrolling by 4 */
|
||||
i = (uint32_t) S->Nby2 >> 2u;
|
||||
|
||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
||||
** a second loop below computes the remaining 1 to 3 samples. */
|
||||
do
|
||||
{
|
||||
/* Re-ordering of even and odd elements */
|
||||
/* pState[i] = pInlineBuffer[2*i] */
|
||||
*pS1++ = *pbuff++;
|
||||
/* pState[N-i-1] = pInlineBuffer[2*i+1] */
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Initializing the loop counter to N/4 instead of N for loop unrolling */
|
||||
i = (uint32_t) S->N >> 2u;
|
||||
|
||||
/* Processing with loop unrolling 4 times as N is always multiple of 4.
|
||||
* Compute 4 outputs at a time */
|
||||
do
|
||||
{
|
||||
/* Writing the re-ordered output back to inplace input buffer */
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/* ---------------------------------------------------------
|
||||
* Step2: Calculate RFFT for N-point input
|
||||
* ---------------------------------------------------------- */
|
||||
/* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
|
||||
arm_rfft_q15(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_q15(pState, weights, pState, S->N);
|
||||
|
||||
/* The output of complex multiplication is in 3.13 format.
|
||||
* Hence changing the format of N (i.e. 2*N elements) complex numbers to 1.15 format by shifting left by 2 bits. */
|
||||
arm_shift_q15(pState, 2, pState, S->N * 2);
|
||||
|
||||
/* ----------- Post-processing ---------- */
|
||||
/* DCT-IV can be obtained from DCT-II by the equation,
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* Hence, Y4(0) = Y2(0)/2 */
|
||||
/* Getting only real part from the output and Converting to DCT-IV */
|
||||
|
||||
/* Initializing the loop counter to N >> 2 for loop unrolling by 4 */
|
||||
i = ((uint32_t) S->N - 1u) >> 2u;
|
||||
|
||||
/* pbuff initialized to input buffer. */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
|
||||
in = *pS1++ >> 1u;
|
||||
/* input buffer acts as inplace, so output values are stored in the input itself. */
|
||||
*pbuff++ = in;
|
||||
|
||||
/* pState pointer is incremented twice as the real values are located alternatively in the array */
|
||||
pS1++;
|
||||
|
||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
||||
** a second loop below computes the remaining 1 to 3 samples. */
|
||||
do
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
|
||||
** No loop unrolling is used. */
|
||||
i = ((uint32_t) S->N - 1u) % 0x4u;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
}
|
||||
|
||||
|
||||
/*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
|
||||
|
||||
/* Initializing the loop counter to N/4 instead of N for loop unrolling */
|
||||
i = (uint32_t) S->N >> 2u;
|
||||
|
||||
/* pbuff initialized to the pInlineBuffer(now contains the output values) */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* Processing with loop unrolling 4 times as N is always multiple of 4. Compute 4 outputs at a time */
|
||||
do
|
||||
{
|
||||
/* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
#else
|
||||
|
||||
/* Run the below code for Cortex-M0 */
|
||||
|
||||
/* Initializing the loop counter to N/2 */
|
||||
i = (uint32_t) S->Nby2;
|
||||
|
||||
do
|
||||
{
|
||||
/* Re-ordering of even and odd elements */
|
||||
/* pState[i] = pInlineBuffer[2*i] */
|
||||
*pS1++ = *pbuff++;
|
||||
/* pState[N-i-1] = pInlineBuffer[2*i+1] */
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = (uint32_t) S->N;
|
||||
|
||||
do
|
||||
{
|
||||
/* Writing the re-ordered output back to inplace input buffer */
|
||||
*pbuff++ = *pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/* ---------------------------------------------------------
|
||||
* Step2: Calculate RFFT for N-point input
|
||||
* ---------------------------------------------------------- */
|
||||
/* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
|
||||
arm_rfft_q15(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_q15(pState, weights, pState, S->N);
|
||||
|
||||
/* The output of complex multiplication is in 3.13 format.
|
||||
* Hence changing the format of N (i.e. 2*N elements) complex numbers to 1.15 format by shifting left by 2 bits. */
|
||||
arm_shift_q15(pState, 2, pState, S->N * 2);
|
||||
|
||||
/* ----------- Post-processing ---------- */
|
||||
/* DCT-IV can be obtained from DCT-II by the equation,
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* Hence, Y4(0) = Y2(0)/2 */
|
||||
/* Getting only real part from the output and Converting to DCT-IV */
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = ((uint32_t) S->N - 1u);
|
||||
|
||||
/* pbuff initialized to input buffer. */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
|
||||
in = *pS1++ >> 1u;
|
||||
/* input buffer acts as inplace, so output values are stored in the input itself. */
|
||||
*pbuff++ = in;
|
||||
|
||||
/* pState pointer is incremented twice as the real values are located alternatively in the array */
|
||||
pS1++;
|
||||
|
||||
do
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = (uint32_t) S->N;
|
||||
|
||||
/* pbuff initialized to the pInlineBuffer(now contains the output values) */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
do
|
||||
{
|
||||
/* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q15_t) (((q31_t) in * S->normalize) >> 15));
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of DCT4_IDCT4 group
|
||||
*/
|
@ -0,0 +1,395 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_dct4_q31.c
|
||||
*
|
||||
* Description: Processing function of DCT4 & IDCT4 Q31.
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
/**
|
||||
* @addtogroup DCT4_IDCT4
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the Q31 DCT4/IDCT4.
|
||||
* @param[in] *S points to an instance of the Q31 DCT4 structure.
|
||||
* @param[in] *pState points to state buffer.
|
||||
* @param[in,out] *pInlineBuffer points to the in-place input and output buffer.
|
||||
* @return none.
|
||||
* \par Input an output formats:
|
||||
* Input samples need to be downscaled by 1 bit to avoid saturations in the Q31 DCT process,
|
||||
* as the conversion from DCT2 to DCT4 involves one subtraction.
|
||||
* Internally inputs are downscaled in the RFFT process function to avoid overflows.
|
||||
* Number of bits downscaled, depends on the size of the transform.
|
||||
* The input and output formats for different DCT sizes and number of bits to upscale are mentioned in the table below:
|
||||
*
|
||||
* \image html dct4FormatsQ31Table.gif
|
||||
*/
|
||||
|
||||
void arm_dct4_q31(
|
||||
const arm_dct4_instance_q31 * S,
|
||||
q31_t * pState,
|
||||
q31_t * pInlineBuffer)
|
||||
{
|
||||
uint16_t i; /* Loop counter */
|
||||
q31_t *weights = S->pTwiddle; /* Pointer to the Weights table */
|
||||
q31_t *cosFact = S->pCosFactor; /* Pointer to the cos factors table */
|
||||
q31_t *pS1, *pS2, *pbuff; /* Temporary pointers for input buffer and pState buffer */
|
||||
q31_t in; /* Temporary variable */
|
||||
|
||||
|
||||
/* DCT4 computation involves DCT2 (which is calculated using RFFT)
|
||||
* along with some pre-processing and post-processing.
|
||||
* Computational procedure is explained as follows:
|
||||
* (a) Pre-processing involves multiplying input with cos factor,
|
||||
* r(n) = 2 * u(n) * cos(pi*(2*n+1)/(4*n))
|
||||
* where,
|
||||
* r(n) -- output of preprocessing
|
||||
* u(n) -- input to preprocessing(actual Source buffer)
|
||||
* (b) Calculation of DCT2 using FFT is divided into three steps:
|
||||
* Step1: Re-ordering of even and odd elements of input.
|
||||
* Step2: Calculating FFT of the re-ordered input.
|
||||
* Step3: Taking the real part of the product of FFT output and weights.
|
||||
* (c) Post-processing - DCT4 can be obtained from DCT2 output using the following equation:
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* where,
|
||||
* Y4 -- DCT4 output, Y2 -- DCT2 output
|
||||
* (d) Multiplying the output with the normalizing factor sqrt(2/N).
|
||||
*/
|
||||
|
||||
/*-------- Pre-processing ------------*/
|
||||
/* Multiplying input with cos factor i.e. r(n) = 2 * x(n) * cos(pi*(2*n+1)/(4*n)) */
|
||||
arm_mult_q31(pInlineBuffer, cosFact, pInlineBuffer, S->N);
|
||||
arm_shift_q31(pInlineBuffer, 1, pInlineBuffer, S->N);
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* Step1: Re-ordering of even and odd elements as
|
||||
* pState[i] = pInlineBuffer[2*i] and
|
||||
* pState[N-i-1] = pInlineBuffer[2*i+1] where i = 0 to N/2
|
||||
---------------------------------------------------------------------*/
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* pS2 initialized to pState+N-1, so that it points to the end of the state buffer */
|
||||
pS2 = pState + (S->N - 1u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
||||
|
||||
/* Initializing the loop counter to N/2 >> 2 for loop unrolling by 4 */
|
||||
i = S->Nby2 >> 2u;
|
||||
|
||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
||||
** a second loop below computes the remaining 1 to 3 samples. */
|
||||
do
|
||||
{
|
||||
/* Re-ordering of even and odd elements */
|
||||
/* pState[i] = pInlineBuffer[2*i] */
|
||||
*pS1++ = *pbuff++;
|
||||
/* pState[N-i-1] = pInlineBuffer[2*i+1] */
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
*pS1++ = *pbuff++;
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Initializing the loop counter to N/4 instead of N for loop unrolling */
|
||||
i = S->N >> 2u;
|
||||
|
||||
/* Processing with loop unrolling 4 times as N is always multiple of 4.
|
||||
* Compute 4 outputs at a time */
|
||||
do
|
||||
{
|
||||
/* Writing the re-ordered output back to inplace input buffer */
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
*pbuff++ = *pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/* ---------------------------------------------------------
|
||||
* Step2: Calculate RFFT for N-point input
|
||||
* ---------------------------------------------------------- */
|
||||
/* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
|
||||
arm_rfft_q31(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_q31(pState, weights, pState, S->N);
|
||||
|
||||
/* The output of complex multiplication is in 3.29 format.
|
||||
* Hence changing the format of N (i.e. 2*N elements) complex numbers to 1.31 format by shifting left by 2 bits. */
|
||||
arm_shift_q31(pState, 2, pState, S->N * 2);
|
||||
|
||||
/* ----------- Post-processing ---------- */
|
||||
/* DCT-IV can be obtained from DCT-II by the equation,
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* Hence, Y4(0) = Y2(0)/2 */
|
||||
/* Getting only real part from the output and Converting to DCT-IV */
|
||||
|
||||
/* Initializing the loop counter to N >> 2 for loop unrolling by 4 */
|
||||
i = (S->N - 1u) >> 2u;
|
||||
|
||||
/* pbuff initialized to input buffer. */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
|
||||
in = *pS1++ >> 1u;
|
||||
/* input buffer acts as inplace, so output values are stored in the input itself. */
|
||||
*pbuff++ = in;
|
||||
|
||||
/* pState pointer is incremented twice as the real values are located alternatively in the array */
|
||||
pS1++;
|
||||
|
||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
||||
** a second loop below computes the remaining 1 to 3 samples. */
|
||||
do
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
|
||||
** No loop unrolling is used. */
|
||||
i = (S->N - 1u) % 0x4u;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
}
|
||||
|
||||
|
||||
/*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
|
||||
|
||||
/* Initializing the loop counter to N/4 instead of N for loop unrolling */
|
||||
i = S->N >> 2u;
|
||||
|
||||
/* pbuff initialized to the pInlineBuffer(now contains the output values) */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* Processing with loop unrolling 4 times as N is always multiple of 4. Compute 4 outputs at a time */
|
||||
do
|
||||
{
|
||||
/* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q31_t) (((q63_t) in * S->normalize) >> 31));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q31_t) (((q63_t) in * S->normalize) >> 31));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q31_t) (((q63_t) in * S->normalize) >> 31));
|
||||
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q31_t) (((q63_t) in * S->normalize) >> 31));
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
#else
|
||||
|
||||
/* Run the below code for Cortex-M0 */
|
||||
|
||||
/* Initializing the loop counter to N/2 */
|
||||
i = S->Nby2;
|
||||
|
||||
do
|
||||
{
|
||||
/* Re-ordering of even and odd elements */
|
||||
/* pState[i] = pInlineBuffer[2*i] */
|
||||
*pS1++ = *pbuff++;
|
||||
/* pState[N-i-1] = pInlineBuffer[2*i+1] */
|
||||
*pS2-- = *pbuff++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
/* pbuff initialized to input buffer */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = S->N;
|
||||
|
||||
do
|
||||
{
|
||||
/* Writing the re-ordered output back to inplace input buffer */
|
||||
*pbuff++ = *pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
|
||||
/* ---------------------------------------------------------
|
||||
* Step2: Calculate RFFT for N-point input
|
||||
* ---------------------------------------------------------- */
|
||||
/* pInlineBuffer is real input of length N , pState is the complex output of length 2N */
|
||||
arm_rfft_q31(S->pRfft, pInlineBuffer, pState);
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
* Step3: Multiply the FFT output with the weights.
|
||||
*----------------------------------------------------------------------*/
|
||||
arm_cmplx_mult_cmplx_q31(pState, weights, pState, S->N);
|
||||
|
||||
/* The output of complex multiplication is in 3.29 format.
|
||||
* Hence changing the format of N (i.e. 2*N elements) complex numbers to 1.31 format by shifting left by 2 bits. */
|
||||
arm_shift_q31(pState, 2, pState, S->N * 2);
|
||||
|
||||
/* ----------- Post-processing ---------- */
|
||||
/* DCT-IV can be obtained from DCT-II by the equation,
|
||||
* Y4(k) = Y2(k) - Y4(k-1) and Y4(-1) = Y4(0)
|
||||
* Hence, Y4(0) = Y2(0)/2 */
|
||||
/* Getting only real part from the output and Converting to DCT-IV */
|
||||
|
||||
/* pbuff initialized to input buffer. */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
/* pS1 initialized to pState */
|
||||
pS1 = pState;
|
||||
|
||||
/* Calculating Y4(0) from Y2(0) using Y4(0) = Y2(0)/2 */
|
||||
in = *pS1++ >> 1u;
|
||||
/* input buffer acts as inplace, so output values are stored in the input itself. */
|
||||
*pbuff++ = in;
|
||||
|
||||
/* pState pointer is incremented twice as the real values are located alternatively in the array */
|
||||
pS1++;
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = (S->N - 1u);
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
/* Calculating Y4(1) to Y4(N-1) from Y2 using equation Y4(k) = Y2(k) - Y4(k-1) */
|
||||
/* pState pointer (pS1) is incremented twice as the real values are located alternatively in the array */
|
||||
in = *pS1++ - in;
|
||||
*pbuff++ = in;
|
||||
/* points to the next real value */
|
||||
pS1++;
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
}
|
||||
|
||||
|
||||
/*------------ Normalizing the output by multiplying with the normalizing factor ----------*/
|
||||
|
||||
/* Initializing the loop counter */
|
||||
i = S->N;
|
||||
|
||||
/* pbuff initialized to the pInlineBuffer(now contains the output values) */
|
||||
pbuff = pInlineBuffer;
|
||||
|
||||
do
|
||||
{
|
||||
/* Multiplying pInlineBuffer with the normalizing factor sqrt(2/N) */
|
||||
in = *pbuff;
|
||||
*pbuff++ = ((q31_t) (((q63_t) in * S->normalize) >> 31));
|
||||
|
||||
/* Decrement the loop counter */
|
||||
i--;
|
||||
} while(i > 0u);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of DCT4_IDCT4 group
|
||||
*/
|
@ -0,0 +1,329 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_rfft_f32.c
|
||||
*
|
||||
* Description: RFFT & RIFFT Floating point process function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
extern void arm_radix4_butterfly_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftLen,
|
||||
float32_t * pCoef,
|
||||
uint16_t twidCoefModifier);
|
||||
|
||||
extern void arm_radix4_butterfly_inverse_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftLen,
|
||||
float32_t * pCoef,
|
||||
uint16_t twidCoefModifier,
|
||||
float32_t onebyfftLen);
|
||||
|
||||
extern void arm_bitreversal_f32(
|
||||
float32_t * pSrc,
|
||||
uint16_t fftSize,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/*--------------------------------------------------------------------
|
||||
* Internal functions prototypes
|
||||
*--------------------------------------------------------------------*/
|
||||
|
||||
void arm_split_rfft_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pATable,
|
||||
float32_t * pBTable,
|
||||
float32_t * pDst,
|
||||
uint32_t modifier);
|
||||
void arm_split_rifft_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pATable,
|
||||
float32_t * pBTable,
|
||||
float32_t * pDst,
|
||||
uint32_t modifier);
|
||||
|
||||
/**
|
||||
* @addtogroup RealFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the floating-point RFFT/RIFFT.
|
||||
* @deprecated Do not use this function. It has been superceded by \ref arm_rfft_fast_f32 and will be removed
|
||||
* in the future.
|
||||
* @param[in] *S points to an instance of the floating-point RFFT/RIFFT structure.
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_rfft_f32(
|
||||
const arm_rfft_instance_f32 * S,
|
||||
float32_t * pSrc,
|
||||
float32_t * pDst)
|
||||
{
|
||||
const arm_cfft_radix4_instance_f32 *S_CFFT = S->pCfft;
|
||||
|
||||
|
||||
/* Calculation of Real IFFT of input */
|
||||
if(S->ifftFlagR == 1u)
|
||||
{
|
||||
/* Real IFFT core process */
|
||||
arm_split_rifft_f32(pSrc, S->fftLenBy2, S->pTwiddleAReal,
|
||||
S->pTwiddleBReal, pDst, S->twidCoefRModifier);
|
||||
|
||||
|
||||
/* Complex radix-4 IFFT process */
|
||||
arm_radix4_butterfly_inverse_f32(pDst, S_CFFT->fftLen,
|
||||
S_CFFT->pTwiddle,
|
||||
S_CFFT->twidCoefModifier,
|
||||
S_CFFT->onebyfftLen);
|
||||
|
||||
/* Bit reversal process */
|
||||
if(S->bitReverseFlagR == 1u)
|
||||
{
|
||||
arm_bitreversal_f32(pDst, S_CFFT->fftLen,
|
||||
S_CFFT->bitRevFactor, S_CFFT->pBitRevTable);
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
|
||||
/* Calculation of RFFT of input */
|
||||
|
||||
/* Complex radix-4 FFT process */
|
||||
arm_radix4_butterfly_f32(pSrc, S_CFFT->fftLen,
|
||||
S_CFFT->pTwiddle, S_CFFT->twidCoefModifier);
|
||||
|
||||
/* Bit reversal process */
|
||||
if(S->bitReverseFlagR == 1u)
|
||||
{
|
||||
arm_bitreversal_f32(pSrc, S_CFFT->fftLen,
|
||||
S_CFFT->bitRevFactor, S_CFFT->pBitRevTable);
|
||||
}
|
||||
|
||||
|
||||
/* Real FFT core process */
|
||||
arm_split_rfft_f32(pSrc, S->fftLenBy2, S->pTwiddleAReal,
|
||||
S->pTwiddleBReal, pDst, S->twidCoefRModifier);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of RealFFT group
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Core Real FFT process
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[in] fftLen length of FFT.
|
||||
* @param[in] *pATable points to the twiddle Coef A buffer.
|
||||
* @param[in] *pBTable points to the twiddle Coef B buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_split_rfft_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pATable,
|
||||
float32_t * pBTable,
|
||||
float32_t * pDst,
|
||||
uint32_t modifier)
|
||||
{
|
||||
uint32_t i; /* Loop Counter */
|
||||
float32_t outR, outI; /* Temporary variables for output */
|
||||
float32_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */
|
||||
float32_t CoefA1, CoefA2, CoefB1; /* Temporary variables for twiddle coefficients */
|
||||
float32_t *pDst1 = &pDst[2], *pDst2 = &pDst[(4u * fftLen) - 1u]; /* temp pointers for output buffer */
|
||||
float32_t *pSrc1 = &pSrc[2], *pSrc2 = &pSrc[(2u * fftLen) - 1u]; /* temp pointers for input buffer */
|
||||
|
||||
/* Init coefficient pointers */
|
||||
pCoefA = &pATable[modifier * 2u];
|
||||
pCoefB = &pBTable[modifier * 2u];
|
||||
|
||||
i = fftLen - 1u;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
/*
|
||||
outR = (pSrc[2 * i] * pATable[2 * i] - pSrc[2 * i + 1] * pATable[2 * i + 1]
|
||||
+ pSrc[2 * n - 2 * i] * pBTable[2 * i] +
|
||||
pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
*/
|
||||
|
||||
/* outI = (pIn[2 * i + 1] * pATable[2 * i] + pIn[2 * i] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]); */
|
||||
|
||||
/* read pATable[2 * i] */
|
||||
CoefA1 = *pCoefA++;
|
||||
/* pATable[2 * i + 1] */
|
||||
CoefA2 = *pCoefA;
|
||||
|
||||
/* pSrc[2 * i] * pATable[2 * i] */
|
||||
outR = *pSrc1 * CoefA1;
|
||||
/* pSrc[2 * i] * CoefA2 */
|
||||
outI = *pSrc1++ * CoefA2;
|
||||
|
||||
/* (pSrc[2 * i + 1] + pSrc[2 * fftLen - 2 * i + 1]) * CoefA2 */
|
||||
outR -= (*pSrc1 + *pSrc2) * CoefA2;
|
||||
/* pSrc[2 * i + 1] * CoefA1 */
|
||||
outI += *pSrc1++ * CoefA1;
|
||||
|
||||
CoefB1 = *pCoefB;
|
||||
|
||||
/* pSrc[2 * fftLen - 2 * i + 1] * CoefB1 */
|
||||
outI -= *pSrc2-- * CoefB1;
|
||||
/* pSrc[2 * fftLen - 2 * i] * CoefA2 */
|
||||
outI -= *pSrc2 * CoefA2;
|
||||
|
||||
/* pSrc[2 * fftLen - 2 * i] * CoefB1 */
|
||||
outR += *pSrc2-- * CoefB1;
|
||||
|
||||
/* write output */
|
||||
*pDst1++ = outR;
|
||||
*pDst1++ = outI;
|
||||
|
||||
/* write complex conjugate output */
|
||||
*pDst2-- = -outI;
|
||||
*pDst2-- = outR;
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (modifier * 2u);
|
||||
pCoefA = pCoefA + ((modifier * 2u) - 1u);
|
||||
|
||||
i--;
|
||||
|
||||
}
|
||||
|
||||
pDst[2u * fftLen] = pSrc[0] - pSrc[1];
|
||||
pDst[(2u * fftLen) + 1u] = 0.0f;
|
||||
|
||||
pDst[0] = pSrc[0] + pSrc[1];
|
||||
pDst[1] = 0.0f;
|
||||
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* @brief Core Real IFFT process
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[in] fftLen length of FFT.
|
||||
* @param[in] *pATable points to the twiddle Coef A buffer.
|
||||
* @param[in] *pBTable points to the twiddle Coef B buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_split_rifft_f32(
|
||||
float32_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
float32_t * pATable,
|
||||
float32_t * pBTable,
|
||||
float32_t * pDst,
|
||||
uint32_t modifier)
|
||||
{
|
||||
float32_t outR, outI; /* Temporary variables for output */
|
||||
float32_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */
|
||||
float32_t CoefA1, CoefA2, CoefB1; /* Temporary variables for twiddle coefficients */
|
||||
float32_t *pSrc1 = &pSrc[0], *pSrc2 = &pSrc[(2u * fftLen) + 1u];
|
||||
|
||||
pCoefA = &pATable[0];
|
||||
pCoefB = &pBTable[0];
|
||||
|
||||
while(fftLen > 0u)
|
||||
{
|
||||
/*
|
||||
outR = (pIn[2 * i] * pATable[2 * i] + pIn[2 * i + 1] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
|
||||
outI = (pIn[2 * i + 1] * pATable[2 * i] - pIn[2 * i] * pATable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]);
|
||||
|
||||
*/
|
||||
|
||||
CoefA1 = *pCoefA++;
|
||||
CoefA2 = *pCoefA;
|
||||
|
||||
/* outR = (pSrc[2 * i] * CoefA1 */
|
||||
outR = *pSrc1 * CoefA1;
|
||||
|
||||
/* - pSrc[2 * i] * CoefA2 */
|
||||
outI = -(*pSrc1++) * CoefA2;
|
||||
|
||||
/* (pSrc[2 * i + 1] + pSrc[2 * fftLen - 2 * i + 1]) * CoefA2 */
|
||||
outR += (*pSrc1 + *pSrc2) * CoefA2;
|
||||
|
||||
/* pSrc[2 * i + 1] * CoefA1 */
|
||||
outI += (*pSrc1++) * CoefA1;
|
||||
|
||||
CoefB1 = *pCoefB;
|
||||
|
||||
/* - pSrc[2 * fftLen - 2 * i + 1] * CoefB1 */
|
||||
outI -= *pSrc2-- * CoefB1;
|
||||
|
||||
/* pSrc[2 * fftLen - 2 * i] * CoefB1 */
|
||||
outR += *pSrc2 * CoefB1;
|
||||
|
||||
/* pSrc[2 * fftLen - 2 * i] * CoefA2 */
|
||||
outI += *pSrc2-- * CoefA2;
|
||||
|
||||
/* write output */
|
||||
*pDst++ = outR;
|
||||
*pDst++ = outI;
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (modifier * 2u);
|
||||
pCoefA = pCoefA + ((modifier * 2u) - 1u);
|
||||
|
||||
/* Decrement loop count */
|
||||
fftLen--;
|
||||
}
|
||||
|
||||
}
|
@ -0,0 +1,354 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_rfft_f32.c
|
||||
*
|
||||
* Description: RFFT & RIFFT Floating point process function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void stage_rfft_f32(
|
||||
arm_rfft_fast_instance_f32 * S,
|
||||
float32_t * p, float32_t * pOut)
|
||||
{
|
||||
uint32_t k; /* Loop Counter */
|
||||
float32_t twR, twI; /* RFFT Twiddle coefficients */
|
||||
float32_t * pCoeff = S->pTwiddleRFFT; /* Points to RFFT Twiddle factors */
|
||||
float32_t *pA = p; /* increasing pointer */
|
||||
float32_t *pB = p; /* decreasing pointer */
|
||||
float32_t xAR, xAI, xBR, xBI; /* temporary variables */
|
||||
float32_t t1a, t1b; /* temporary variables */
|
||||
float32_t p0, p1, p2, p3; /* temporary variables */
|
||||
|
||||
|
||||
k = (S->Sint).fftLen - 1;
|
||||
|
||||
/* Pack first and last sample of the frequency domain together */
|
||||
|
||||
xBR = pB[0];
|
||||
xBI = pB[1];
|
||||
xAR = pA[0];
|
||||
xAI = pA[1];
|
||||
|
||||
twR = *pCoeff++ ;
|
||||
twI = *pCoeff++ ;
|
||||
|
||||
// U1 = XA(1) + XB(1); % It is real
|
||||
t1a = xBR + xAR ;
|
||||
|
||||
// U2 = XB(1) - XA(1); % It is imaginary
|
||||
t1b = xBI + xAI ;
|
||||
|
||||
// real(tw * (xB - xA)) = twR * (xBR - xAR) - twI * (xBI - xAI);
|
||||
// imag(tw * (xB - xA)) = twI * (xBR - xAR) + twR * (xBI - xAI);
|
||||
*pOut++ = 0.5f * ( t1a + t1b );
|
||||
*pOut++ = 0.5f * ( t1a - t1b );
|
||||
|
||||
// XA(1) = 1/2*( U1 - imag(U2) + i*( U1 +imag(U2) ));
|
||||
pB = p + 2*k;
|
||||
pA += 2;
|
||||
|
||||
do
|
||||
{
|
||||
/*
|
||||
function X = my_split_rfft(X, ifftFlag)
|
||||
% X is a series of real numbers
|
||||
L = length(X);
|
||||
XC = X(1:2:end) +i*X(2:2:end);
|
||||
XA = fft(XC);
|
||||
XB = conj(XA([1 end:-1:2]));
|
||||
TW = i*exp(-2*pi*i*[0:L/2-1]/L).';
|
||||
for l = 2:L/2
|
||||
XA(l) = 1/2 * (XA(l) + XB(l) + TW(l) * (XB(l) - XA(l)));
|
||||
end
|
||||
XA(1) = 1/2* (XA(1) + XB(1) + TW(1) * (XB(1) - XA(1))) + i*( 1/2*( XA(1) + XB(1) + i*( XA(1) - XB(1))));
|
||||
X = XA;
|
||||
*/
|
||||
|
||||
xBI = pB[1];
|
||||
xBR = pB[0];
|
||||
xAR = pA[0];
|
||||
xAI = pA[1];
|
||||
|
||||
twR = *pCoeff++;
|
||||
twI = *pCoeff++;
|
||||
|
||||
t1a = xBR - xAR ;
|
||||
t1b = xBI + xAI ;
|
||||
|
||||
// real(tw * (xB - xA)) = twR * (xBR - xAR) - twI * (xBI - xAI);
|
||||
// imag(tw * (xB - xA)) = twI * (xBR - xAR) + twR * (xBI - xAI);
|
||||
p0 = twR * t1a;
|
||||
p1 = twI * t1a;
|
||||
p2 = twR * t1b;
|
||||
p3 = twI * t1b;
|
||||
|
||||
*pOut++ = 0.5f * (xAR + xBR + p0 + p3 ); //xAR
|
||||
*pOut++ = 0.5f * (xAI - xBI + p1 - p2 ); //xAI
|
||||
|
||||
pA += 2;
|
||||
pB -= 2;
|
||||
k--;
|
||||
} while(k > 0u);
|
||||
}
|
||||
|
||||
/* Prepares data for inverse cfft */
|
||||
void merge_rfft_f32(
|
||||
arm_rfft_fast_instance_f32 * S,
|
||||
float32_t * p, float32_t * pOut)
|
||||
{
|
||||
uint32_t k; /* Loop Counter */
|
||||
float32_t twR, twI; /* RFFT Twiddle coefficients */
|
||||
float32_t *pCoeff = S->pTwiddleRFFT; /* Points to RFFT Twiddle factors */
|
||||
float32_t *pA = p; /* increasing pointer */
|
||||
float32_t *pB = p; /* decreasing pointer */
|
||||
float32_t xAR, xAI, xBR, xBI; /* temporary variables */
|
||||
float32_t t1a, t1b, r, s, t, u; /* temporary variables */
|
||||
|
||||
k = (S->Sint).fftLen - 1;
|
||||
|
||||
xAR = pA[0];
|
||||
xAI = pA[1];
|
||||
|
||||
pCoeff += 2 ;
|
||||
|
||||
*pOut++ = 0.5f * ( xAR + xAI );
|
||||
*pOut++ = 0.5f * ( xAR - xAI );
|
||||
|
||||
pB = p + 2*k ;
|
||||
pA += 2 ;
|
||||
|
||||
while(k > 0u)
|
||||
{
|
||||
/* G is half of the frequency complex spectrum */
|
||||
//for k = 2:N
|
||||
// Xk(k) = 1/2 * (G(k) + conj(G(N-k+2)) + Tw(k)*( G(k) - conj(G(N-k+2))));
|
||||
xBI = pB[1] ;
|
||||
xBR = pB[0] ;
|
||||
xAR = pA[0];
|
||||
xAI = pA[1];
|
||||
|
||||
twR = *pCoeff++;
|
||||
twI = *pCoeff++;
|
||||
|
||||
t1a = xAR - xBR ;
|
||||
t1b = xAI + xBI ;
|
||||
|
||||
r = twR * t1a;
|
||||
s = twI * t1b;
|
||||
t = twI * t1a;
|
||||
u = twR * t1b;
|
||||
|
||||
// real(tw * (xA - xB)) = twR * (xAR - xBR) - twI * (xAI - xBI);
|
||||
// imag(tw * (xA - xB)) = twI * (xAR - xBR) + twR * (xAI - xBI);
|
||||
*pOut++ = 0.5f * (xAR + xBR - r - s ); //xAR
|
||||
*pOut++ = 0.5f * (xAI - xBI + t - u ); //xAI
|
||||
|
||||
pA += 2;
|
||||
pB -= 2;
|
||||
k--;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @defgroup Fast Real FFT Functions
|
||||
*
|
||||
* \par
|
||||
* The CMSIS DSP library includes specialized algorithms for computing the
|
||||
* FFT of real data sequences. The FFT is defined over complex data but
|
||||
* in many applications the input is real. Real FFT algorithms take advantage
|
||||
* of the symmetry properties of the FFT and have a speed advantage over complex
|
||||
* algorithms of the same length.
|
||||
* \par
|
||||
* The Fast RFFT algorith relays on the mixed radix CFFT that save processor usage.
|
||||
* \par
|
||||
* The real length N forward FFT of a sequence is computed using the steps shown below.
|
||||
* \par
|
||||
* \image html RFFT.gif "Real Fast Fourier Transform"
|
||||
* \par
|
||||
* The real sequence is initially treated as if it were complex to perform a CFFT.
|
||||
* Later, a processing stage reshapes the data to obtain half of the frequency spectrum
|
||||
* in complex format. Except the first complex number that contains the two real numbers
|
||||
* X[0] and X[N/2] all the data is complex. In other words, the first complex sample
|
||||
* contains two real values packed.
|
||||
* \par
|
||||
* The input for the inverse RFFT should keep the same format as the output of the
|
||||
* forward RFFT. A first processing stage pre-process the data to later perform an
|
||||
* inverse CFFT.
|
||||
* \par
|
||||
* \image html RIFFT.gif "Real Inverse Fast Fourier Transform"
|
||||
* \par
|
||||
* The algorithms for floating-point, Q15, and Q31 data are slightly different
|
||||
* and we describe each algorithm in turn.
|
||||
* \par Floating-point
|
||||
* The main functions are <code>arm_rfft_fast_f32()</code>
|
||||
* and <code>arm_rfft_fast_init_f32()</code>. The older functions
|
||||
* <code>arm_rfft_f32()</code> and <code>arm_rfft_init_f32()</code> have been
|
||||
* deprecated but are still documented.
|
||||
* \par
|
||||
* The FFT of a real N-point sequence has even symmetry in the frequency
|
||||
* domain. The second half of the data equals the conjugate of the first half
|
||||
* flipped in frequency:
|
||||
* <pre>
|
||||
*X[0] - real data
|
||||
*X[1] - complex data
|
||||
*X[2] - complex data
|
||||
*...
|
||||
*X[fftLen/2-1] - complex data
|
||||
*X[fftLen/2] - real data
|
||||
*X[fftLen/2+1] - conjugate of X[fftLen/2-1]
|
||||
*X[fftLen/2+2] - conjugate of X[fftLen/2-2]
|
||||
*...
|
||||
*X[fftLen-1] - conjugate of X[1]
|
||||
* </pre>
|
||||
* Looking at the data, we see that we can uniquely represent the FFT using only
|
||||
* <pre>
|
||||
*N/2+1 samples:
|
||||
*X[0] - real data
|
||||
*X[1] - complex data
|
||||
*X[2] - complex data
|
||||
*...
|
||||
*X[fftLen/2-1] - complex data
|
||||
*X[fftLen/2] - real data
|
||||
* </pre>
|
||||
* Looking more closely we see that the first and last samples are real valued.
|
||||
* They can be packed together and we can thus represent the FFT of an N-point
|
||||
* real sequence by N/2 complex values:
|
||||
* <pre>
|
||||
*X[0],X[N/2] - packed real data: X[0] + jX[N/2]
|
||||
*X[1] - complex data
|
||||
*X[2] - complex data
|
||||
*...
|
||||
*X[fftLen/2-1] - complex data
|
||||
* </pre>
|
||||
* The real FFT functions pack the frequency domain data in this fashion. The
|
||||
* forward transform outputs the data in this form and the inverse transform
|
||||
* expects input data in this form. The function always performs the needed
|
||||
* bitreversal so that the input and output data is always in normal order. The
|
||||
* functions support lengths of [32, 64, 128, ..., 4096] samples.
|
||||
* \par
|
||||
* The forward and inverse real FFT functions apply the standard FFT scaling; no
|
||||
* scaling on the forward transform and 1/fftLen scaling on the inverse
|
||||
* transform.
|
||||
* \par Q15 and Q31
|
||||
* The real algorithms are defined in a similar manner and utilize N/2 complex
|
||||
* transforms behind the scenes. In the case of fixed-point data, a radix-4
|
||||
* complex transform is performed and this limits the allows sequence lengths to
|
||||
* 128, 512, and 2048 samples.
|
||||
* \par
|
||||
* TBD. We need to document input and output order of data.
|
||||
* \par
|
||||
* The complex transforms used internally include scaling to prevent fixed-point
|
||||
* overflows. The overall scaling equals 1/(fftLen/2).
|
||||
* \par
|
||||
* A separate instance structure must be defined for each transform used but
|
||||
* twiddle factor and bit reversal tables can be reused.
|
||||
* \par
|
||||
* There is also an associated initialization function for each data type.
|
||||
* The initialization function performs the following operations:
|
||||
* - Sets the values of the internal structure fields.
|
||||
* - Initializes twiddle factor table and bit reversal table pointers.
|
||||
* - Initializes the internal complex FFT data structure.
|
||||
* \par
|
||||
* Use of the initialization function is optional.
|
||||
* However, if the initialization function is used, then the instance structure
|
||||
* cannot be placed into a const data section. To place an instance structure
|
||||
* into a const data section, the instance structure should be manually
|
||||
* initialized as follows:
|
||||
* <pre>
|
||||
*arm_rfft_instance_q31 S = {fftLenReal, fftLenBy2, ifftFlagR, bitReverseFlagR, twidCoefRModifier, pTwiddleAReal, pTwiddleBReal, pCfft};
|
||||
*arm_rfft_instance_q15 S = {fftLenReal, fftLenBy2, ifftFlagR, bitReverseFlagR, twidCoefRModifier, pTwiddleAReal, pTwiddleBReal, pCfft};
|
||||
* </pre>
|
||||
* where <code>fftLenReal</code> is the length of the real transform;
|
||||
* <code>fftLenBy2</code> length of the internal complex transform.
|
||||
* <code>ifftFlagR</code> Selects forward (=0) or inverse (=1) transform.
|
||||
* <code>bitReverseFlagR</code> Selects bit reversed output (=0) or normal order
|
||||
* output (=1).
|
||||
* <code>twidCoefRModifier</code> stride modifier for the twiddle factor table.
|
||||
* The value is based on the FFT length;
|
||||
* <code>pTwiddleAReal</code>points to the A array of twiddle coefficients;
|
||||
* <code>pTwiddleBReal</code>points to the B array of twiddle coefficients;
|
||||
* <code>pCfft</code> points to the CFFT Instance structure. The CFFT structure
|
||||
* must also be initialized. Refer to arm_cfft_radix4_f32() for details regarding
|
||||
* static initialization of the complex FFT instance structure.
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup RealFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the floating-point real FFT.
|
||||
* @param[in] *S points to an arm_rfft_fast_instance_f32 structure.
|
||||
* @param[in] *p points to the input buffer.
|
||||
* @param[in] *pOut points to an arm_rfft_fast_instance_f32 structure.
|
||||
* @param[in] ifftFlag RFFT if flag is 0, RIFFT if flag is 1
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_rfft_fast_f32(
|
||||
arm_rfft_fast_instance_f32 * S,
|
||||
float32_t * p, float32_t * pOut,
|
||||
uint8_t ifftFlag)
|
||||
{
|
||||
arm_cfft_instance_f32 * Sint = &(S->Sint);
|
||||
Sint->fftLen = S->fftLenRFFT / 2;
|
||||
|
||||
/* Calculation of Real FFT */
|
||||
if(ifftFlag)
|
||||
{
|
||||
/* Real FFT comression */
|
||||
merge_rfft_f32(S, p, pOut);
|
||||
|
||||
/* Complex radix-4 IFFT process */
|
||||
arm_cfft_f32( Sint, pOut, ifftFlag, 1);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Calculation of RFFT of input */
|
||||
arm_cfft_f32( Sint, p, ifftFlag, 1);
|
||||
|
||||
/* Real FFT extraction */
|
||||
stage_rfft_f32(S, p, pOut);
|
||||
}
|
||||
}
|
||||
|
@ -0,0 +1,139 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_cfft_init_f32.c
|
||||
*
|
||||
* Description: Split Radix Decimation in Frequency CFFT Floating point processing function
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
#include "arm_common_tables.h"
|
||||
|
||||
/**
|
||||
* @ingroup groupTransforms
|
||||
*/
|
||||
|
||||
/**
|
||||
* @addtogroup RealFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Initialization function for the floating-point real FFT.
|
||||
* @param[in,out] *S points to an arm_rfft_fast_instance_f32 structure.
|
||||
* @param[in] fftLen length of the Real Sequence.
|
||||
* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
|
||||
*
|
||||
* \par Description:
|
||||
* \par
|
||||
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
|
||||
* Set(=1) ifftFlag for calculation of CIFFT otherwise RFFT is calculated
|
||||
* \par
|
||||
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
|
||||
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
|
||||
* \par
|
||||
* The parameter <code>fftLen</code> Specifies length of RFFT/CIFFT process. Supported FFT Lengths are 16, 32, 64, 128, 256, 512, 1024, 2048, 4096.
|
||||
* \par
|
||||
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
|
||||
*/
|
||||
arm_status arm_rfft_fast_init_f32(
|
||||
arm_rfft_fast_instance_f32 * S,
|
||||
uint16_t fftLen)
|
||||
{
|
||||
arm_cfft_instance_f32 * Sint;
|
||||
/* Initialise the default arm status */
|
||||
arm_status status = ARM_MATH_SUCCESS;
|
||||
/* Initialise the FFT length */
|
||||
Sint = &(S->Sint);
|
||||
Sint->fftLen = fftLen/2;
|
||||
S->fftLenRFFT = fftLen;
|
||||
/* Initialise the Twiddle coefficient pointer */
|
||||
// S->pTwiddle = (float32_t *) twiddleCoef;
|
||||
|
||||
/* Initializations of structure parameters depending on the FFT length */
|
||||
switch (Sint->fftLen)
|
||||
{
|
||||
case 4096u:
|
||||
/* Initializations of structure parameters for 4096 point FFT */
|
||||
/* Initialise the bit reversal table length */
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE4096_TABLE_LENGTH;
|
||||
/* Initialise the bit reversal table pointer */
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable4096;
|
||||
/* Initialise the 1/fftLen Value */
|
||||
break;
|
||||
case 2048u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE2048_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
|
||||
break;
|
||||
case 1024u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE1024_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
|
||||
break;
|
||||
case 512u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
|
||||
break;
|
||||
case 256u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
|
||||
break;
|
||||
case 128u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
|
||||
break;
|
||||
case 64u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE__64_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
|
||||
break;
|
||||
case 32u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE__32_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
|
||||
break;
|
||||
case 16u:
|
||||
Sint->bitRevLength = ARMBITREVINDEXTABLE__16_TABLE_LENGTH;
|
||||
Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
|
||||
break;
|
||||
default:
|
||||
/* Reporting argument error if fftSize is not valid value */
|
||||
status = ARM_MATH_ARGUMENT_ERROR;
|
||||
break;
|
||||
}
|
||||
|
||||
return (status);
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of RealFFT group
|
||||
*/
|
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
@ -0,0 +1,482 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_rfft_q15.c
|
||||
*
|
||||
* Description: RFFT & RIFFT Q15 process function
|
||||
*
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void arm_radix4_butterfly_q15(
|
||||
q15_t * pSrc16,
|
||||
uint32_t fftLen,
|
||||
q15_t * pCoef16,
|
||||
uint32_t twidCoefModifier);
|
||||
|
||||
void arm_radix4_butterfly_inverse_q15(
|
||||
q15_t * pSrc16,
|
||||
uint32_t fftLen,
|
||||
q15_t * pCoef16,
|
||||
uint32_t twidCoefModifier);
|
||||
|
||||
void arm_bitreversal_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/*--------------------------------------------------------------------
|
||||
* Internal functions prototypes
|
||||
--------------------------------------------------------------------*/
|
||||
|
||||
void arm_split_rfft_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pATable,
|
||||
q15_t * pBTable,
|
||||
q15_t * pDst,
|
||||
uint32_t modifier);
|
||||
|
||||
void arm_split_rifft_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pATable,
|
||||
q15_t * pBTable,
|
||||
q15_t * pDst,
|
||||
uint32_t modifier);
|
||||
|
||||
/**
|
||||
* @addtogroup RealFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the Q15 RFFT/RIFFT.
|
||||
* @param[in] *S points to an instance of the Q15 RFFT/RIFFT structure.
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @return none.
|
||||
*
|
||||
* \par Input an output formats:
|
||||
* \par
|
||||
* Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process.
|
||||
* Hence the output format is different for different RFFT sizes.
|
||||
* The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT:
|
||||
* \par
|
||||
* \image html RFFTQ15.gif "Input and Output Formats for Q15 RFFT"
|
||||
* \par
|
||||
* \image html RIFFTQ15.gif "Input and Output Formats for Q15 RIFFT"
|
||||
*/
|
||||
|
||||
void arm_rfft_q15(
|
||||
const arm_rfft_instance_q15 * S,
|
||||
q15_t * pSrc,
|
||||
q15_t * pDst)
|
||||
{
|
||||
const arm_cfft_radix4_instance_q15 *S_CFFT = S->pCfft;
|
||||
|
||||
/* Calculation of RIFFT of input */
|
||||
if(S->ifftFlagR == 1u)
|
||||
{
|
||||
/* Real IFFT core process */
|
||||
arm_split_rifft_q15(pSrc, S->fftLenBy2, S->pTwiddleAReal,
|
||||
S->pTwiddleBReal, pDst, S->twidCoefRModifier);
|
||||
|
||||
/* Complex readix-4 IFFT process */
|
||||
arm_radix4_butterfly_inverse_q15(pDst, S_CFFT->fftLen,
|
||||
S_CFFT->pTwiddle,
|
||||
S_CFFT->twidCoefModifier);
|
||||
|
||||
/* Bit reversal process */
|
||||
if(S->bitReverseFlagR == 1u)
|
||||
{
|
||||
arm_bitreversal_q15(pDst, S_CFFT->fftLen,
|
||||
S_CFFT->bitRevFactor, S_CFFT->pBitRevTable);
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Calculation of RFFT of input */
|
||||
|
||||
/* Complex readix-4 FFT process */
|
||||
arm_radix4_butterfly_q15(pSrc, S_CFFT->fftLen,
|
||||
S_CFFT->pTwiddle, S_CFFT->twidCoefModifier);
|
||||
|
||||
/* Bit reversal process */
|
||||
if(S->bitReverseFlagR == 1u)
|
||||
{
|
||||
arm_bitreversal_q15(pSrc, S_CFFT->fftLen,
|
||||
S_CFFT->bitRevFactor, S_CFFT->pBitRevTable);
|
||||
}
|
||||
|
||||
arm_split_rfft_q15(pSrc, S->fftLenBy2, S->pTwiddleAReal,
|
||||
S->pTwiddleBReal, pDst, S->twidCoefRModifier);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* @} end of RealFFT group
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Core Real FFT process
|
||||
* @param *pSrc points to the input buffer.
|
||||
* @param fftLen length of FFT.
|
||||
* @param *pATable points to the A twiddle Coef buffer.
|
||||
* @param *pBTable points to the B twiddle Coef buffer.
|
||||
* @param *pDst points to the output buffer.
|
||||
* @param modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
* The function implements a Real FFT
|
||||
*/
|
||||
|
||||
void arm_split_rfft_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pATable,
|
||||
q15_t * pBTable,
|
||||
q15_t * pDst,
|
||||
uint32_t modifier)
|
||||
{
|
||||
uint32_t i; /* Loop Counter */
|
||||
q31_t outR, outI; /* Temporary variables for output */
|
||||
q15_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */
|
||||
q15_t *pSrc1, *pSrc2;
|
||||
|
||||
|
||||
// pSrc[2u * fftLen] = pSrc[0];
|
||||
// pSrc[(2u * fftLen) + 1u] = pSrc[1];
|
||||
|
||||
pCoefA = &pATable[modifier * 2u];
|
||||
pCoefB = &pBTable[modifier * 2u];
|
||||
|
||||
pSrc1 = &pSrc[2];
|
||||
pSrc2 = &pSrc[(2u * fftLen) - 2u];
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
||||
|
||||
i = 1u;
|
||||
|
||||
while(i < fftLen)
|
||||
{
|
||||
/*
|
||||
outR = (pSrc[2 * i] * pATable[2 * i] - pSrc[2 * i + 1] * pATable[2 * i + 1]
|
||||
+ pSrc[2 * n - 2 * i] * pBTable[2 * i] +
|
||||
pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
*/
|
||||
|
||||
/* outI = (pIn[2 * i + 1] * pATable[2 * i] + pIn[2 * i] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]); */
|
||||
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
/* pSrc[2 * i] * pATable[2 * i] - pSrc[2 * i + 1] * pATable[2 * i + 1] */
|
||||
outR = __SMUSD(*__SIMD32(pSrc1), *__SIMD32(pCoefA));
|
||||
|
||||
#else
|
||||
|
||||
/* -(pSrc[2 * i + 1] * pATable[2 * i + 1] - pSrc[2 * i] * pATable[2 * i]) */
|
||||
outR = -(__SMUSD(*__SIMD32(pSrc1), *__SIMD32(pCoefA)));
|
||||
|
||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
|
||||
|
||||
/* pSrc[2 * n - 2 * i] * pBTable[2 * i] +
|
||||
pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1]) */
|
||||
outR = __SMLAD(*__SIMD32(pSrc2), *__SIMD32(pCoefB), outR) >> 15u;
|
||||
|
||||
/* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
outI = __SMUSDX(*__SIMD32(pSrc2)--, *__SIMD32(pCoefB));
|
||||
|
||||
#else
|
||||
|
||||
outI = __SMUSDX(*__SIMD32(pCoefB), *__SIMD32(pSrc2)--);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
|
||||
|
||||
/* (pIn[2 * i + 1] * pATable[2 * i] + pIn[2 * i] * pATable[2 * i + 1] */
|
||||
outI = __SMLADX(*__SIMD32(pSrc1)++, *__SIMD32(pCoefA), outI);
|
||||
|
||||
/* write output */
|
||||
pDst[2u * i] = (q15_t) outR;
|
||||
pDst[(2u * i) + 1u] = outI >> 15u;
|
||||
|
||||
/* write complex conjugate output */
|
||||
pDst[(4u * fftLen) - (2u * i)] = (q15_t) outR;
|
||||
pDst[((4u * fftLen) - (2u * i)) + 1u] = -(outI >> 15u);
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (2u * modifier);
|
||||
pCoefA = pCoefA + (2u * modifier);
|
||||
|
||||
i++;
|
||||
|
||||
}
|
||||
|
||||
pDst[2u * fftLen] = pSrc[0] - pSrc[1];
|
||||
pDst[(2u * fftLen) + 1u] = 0;
|
||||
|
||||
pDst[0] = pSrc[0] + pSrc[1];
|
||||
pDst[1] = 0;
|
||||
|
||||
|
||||
#else
|
||||
|
||||
/* Run the below code for Cortex-M0 */
|
||||
|
||||
i = 1u;
|
||||
|
||||
while(i < fftLen)
|
||||
{
|
||||
/*
|
||||
outR = (pSrc[2 * i] * pATable[2 * i] - pSrc[2 * i + 1] * pATable[2 * i + 1]
|
||||
+ pSrc[2 * n - 2 * i] * pBTable[2 * i] +
|
||||
pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
*/
|
||||
|
||||
outR = *pSrc1 * *pCoefA;
|
||||
outR = outR - (*(pSrc1 + 1) * *(pCoefA + 1));
|
||||
outR = outR + (*pSrc2 * *pCoefB);
|
||||
outR = (outR + (*(pSrc2 + 1) * *(pCoefB + 1))) >> 15;
|
||||
|
||||
|
||||
/* outI = (pIn[2 * i + 1] * pATable[2 * i] + pIn[2 * i] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]);
|
||||
*/
|
||||
|
||||
outI = *pSrc2 * *(pCoefB + 1);
|
||||
outI = outI - (*(pSrc2 + 1) * *pCoefB);
|
||||
outI = outI + (*(pSrc1 + 1) * *pCoefA);
|
||||
outI = outI + (*pSrc1 * *(pCoefA + 1));
|
||||
|
||||
/* update input pointers */
|
||||
pSrc1 += 2u;
|
||||
pSrc2 -= 2u;
|
||||
|
||||
/* write output */
|
||||
pDst[2u * i] = (q15_t) outR;
|
||||
pDst[(2u * i) + 1u] = outI >> 15u;
|
||||
|
||||
/* write complex conjugate output */
|
||||
pDst[(4u * fftLen) - (2u * i)] = (q15_t) outR;
|
||||
pDst[((4u * fftLen) - (2u * i)) + 1u] = -(outI >> 15u);
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (2u * modifier);
|
||||
pCoefA = pCoefA + (2u * modifier);
|
||||
|
||||
i++;
|
||||
|
||||
}
|
||||
|
||||
pDst[2u * fftLen] = pSrc[0] - pSrc[1];
|
||||
pDst[(2u * fftLen) + 1u] = 0;
|
||||
|
||||
pDst[0] = pSrc[0] + pSrc[1];
|
||||
pDst[1] = 0;
|
||||
|
||||
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
||||
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* @brief Core Real IFFT process
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[in] fftLen length of FFT.
|
||||
* @param[in] *pATable points to the twiddle Coef A buffer.
|
||||
* @param[in] *pBTable points to the twiddle Coef B buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
* The function implements a Real IFFT
|
||||
*/
|
||||
void arm_split_rifft_q15(
|
||||
q15_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q15_t * pATable,
|
||||
q15_t * pBTable,
|
||||
q15_t * pDst,
|
||||
uint32_t modifier)
|
||||
{
|
||||
uint32_t i; /* Loop Counter */
|
||||
q31_t outR, outI; /* Temporary variables for output */
|
||||
q15_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */
|
||||
q15_t *pSrc1, *pSrc2;
|
||||
q15_t *pDst1 = &pDst[0];
|
||||
|
||||
pCoefA = &pATable[0];
|
||||
pCoefB = &pBTable[0];
|
||||
|
||||
pSrc1 = &pSrc[0];
|
||||
pSrc2 = &pSrc[2u * fftLen];
|
||||
|
||||
#ifndef ARM_MATH_CM0_FAMILY
|
||||
|
||||
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
||||
|
||||
i = fftLen;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
|
||||
/*
|
||||
outR = (pIn[2 * i] * pATable[2 * i] + pIn[2 * i + 1] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
|
||||
outI = (pIn[2 * i + 1] * pATable[2 * i] - pIn[2 * i] * pATable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]);
|
||||
|
||||
*/
|
||||
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
/* pIn[2 * n - 2 * i] * pBTable[2 * i] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1]) */
|
||||
outR = __SMUSD(*__SIMD32(pSrc2), *__SIMD32(pCoefB));
|
||||
|
||||
#else
|
||||
|
||||
/* -(-pIn[2 * n - 2 * i] * pBTable[2 * i] +
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1])) */
|
||||
outR = -(__SMUSD(*__SIMD32(pSrc2), *__SIMD32(pCoefB)));
|
||||
|
||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
|
||||
|
||||
/* pIn[2 * i] * pATable[2 * i] + pIn[2 * i + 1] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i] */
|
||||
outR = __SMLAD(*__SIMD32(pSrc1), *__SIMD32(pCoefA), outR) >> 15u;
|
||||
|
||||
/*
|
||||
-pIn[2 * n - 2 * i] * pBTable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */
|
||||
outI = __SMUADX(*__SIMD32(pSrc2)--, *__SIMD32(pCoefB));
|
||||
|
||||
/* pIn[2 * i + 1] * pATable[2 * i] - pIn[2 * i] * pATable[2 * i + 1] */
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
outI = __SMLSDX(*__SIMD32(pCoefA), *__SIMD32(pSrc1)++, -outI);
|
||||
|
||||
#else
|
||||
|
||||
outI = __SMLSDX(*__SIMD32(pSrc1)++, *__SIMD32(pCoefA), -outI);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
|
||||
/* write output */
|
||||
|
||||
#ifndef ARM_MATH_BIG_ENDIAN
|
||||
|
||||
*__SIMD32(pDst1)++ = __PKHBT(outR, (outI >> 15u), 16);
|
||||
|
||||
#else
|
||||
|
||||
*__SIMD32(pDst1)++ = __PKHBT((outI >> 15u), outR, 16);
|
||||
|
||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (2u * modifier);
|
||||
pCoefA = pCoefA + (2u * modifier);
|
||||
|
||||
i--;
|
||||
|
||||
}
|
||||
|
||||
|
||||
#else
|
||||
|
||||
/* Run the below code for Cortex-M0 */
|
||||
|
||||
i = fftLen;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
|
||||
/*
|
||||
outR = (pIn[2 * i] * pATable[2 * i] + pIn[2 * i + 1] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
*/
|
||||
|
||||
outR = *pSrc2 * *pCoefB;
|
||||
outR = outR - (*(pSrc2 + 1) * *(pCoefB + 1));
|
||||
outR = outR + (*pSrc1 * *pCoefA);
|
||||
outR = (outR + (*(pSrc1 + 1) * *(pCoefA + 1))) >> 15;
|
||||
|
||||
/*
|
||||
outI = (pIn[2 * i + 1] * pATable[2 * i] - pIn[2 * i] * pATable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]);
|
||||
*/
|
||||
|
||||
outI = *(pSrc1 + 1) * *pCoefA;
|
||||
outI = outI - (*pSrc1 * *(pCoefA + 1));
|
||||
outI = outI - (*pSrc2 * *(pCoefB + 1));
|
||||
outI = outI - (*(pSrc2 + 1) * *(pCoefB));
|
||||
|
||||
/* update input pointers */
|
||||
pSrc1 += 2u;
|
||||
pSrc2 -= 2u;
|
||||
|
||||
/* write output */
|
||||
*pDst1++ = (q15_t) outR;
|
||||
*pDst1++ = (q15_t) (outI >> 15);
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (2u * modifier);
|
||||
pCoefA = pCoefA + (2u * modifier);
|
||||
|
||||
i--;
|
||||
|
||||
}
|
||||
|
||||
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
||||
|
||||
}
|
@ -0,0 +1,349 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
|
||||
*
|
||||
* $Date: 17. January 2013
|
||||
* $Revision: V1.4.1
|
||||
*
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_rfft_q31.c
|
||||
*
|
||||
* Description: RFFT & RIFFT Q31 process function
|
||||
*
|
||||
*
|
||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in
|
||||
* the documentation and/or other materials provided with the
|
||||
* distribution.
|
||||
* - Neither the name of ARM LIMITED nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this
|
||||
* software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||||
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||||
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||||
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
* -------------------------------------------------------------------- */
|
||||
|
||||
#include "arm_math.h"
|
||||
|
||||
void arm_radix4_butterfly_inverse_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint32_t twidCoefModifier);
|
||||
|
||||
void arm_radix4_butterfly_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pCoef,
|
||||
uint32_t twidCoefModifier);
|
||||
|
||||
void arm_bitreversal_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
uint16_t bitRevFactor,
|
||||
uint16_t * pBitRevTab);
|
||||
|
||||
/*--------------------------------------------------------------------
|
||||
* Internal functions prototypes
|
||||
--------------------------------------------------------------------*/
|
||||
|
||||
void arm_split_rfft_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pATable,
|
||||
q31_t * pBTable,
|
||||
q31_t * pDst,
|
||||
uint32_t modifier);
|
||||
|
||||
void arm_split_rifft_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pATable,
|
||||
q31_t * pBTable,
|
||||
q31_t * pDst,
|
||||
uint32_t modifier);
|
||||
|
||||
/**
|
||||
* @addtogroup RealFFT
|
||||
* @{
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Processing function for the Q31 RFFT/RIFFT.
|
||||
* @param[in] *S points to an instance of the Q31 RFFT/RIFFT structure.
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @return none.
|
||||
*
|
||||
* \par Input an output formats:
|
||||
* \par
|
||||
* Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process.
|
||||
* Hence the output format is different for different RFFT sizes.
|
||||
* The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT:
|
||||
* \par
|
||||
* \image html RFFTQ31.gif "Input and Output Formats for Q31 RFFT"
|
||||
*
|
||||
* \par
|
||||
* \image html RIFFTQ31.gif "Input and Output Formats for Q31 RIFFT"
|
||||
*/
|
||||
|
||||
void arm_rfft_q31(
|
||||
const arm_rfft_instance_q31 * S,
|
||||
q31_t * pSrc,
|
||||
q31_t * pDst)
|
||||
{
|
||||
const arm_cfft_radix4_instance_q31 *S_CFFT = S->pCfft;
|
||||
|
||||
/* Calculation of RIFFT of input */
|
||||
if(S->ifftFlagR == 1u)
|
||||
{
|
||||
/* Real IFFT core process */
|
||||
arm_split_rifft_q31(pSrc, S->fftLenBy2, S->pTwiddleAReal,
|
||||
S->pTwiddleBReal, pDst, S->twidCoefRModifier);
|
||||
|
||||
/* Complex readix-4 IFFT process */
|
||||
arm_radix4_butterfly_inverse_q31(pDst, S_CFFT->fftLen,
|
||||
S_CFFT->pTwiddle,
|
||||
S_CFFT->twidCoefModifier);
|
||||
/* Bit reversal process */
|
||||
if(S->bitReverseFlagR == 1u)
|
||||
{
|
||||
arm_bitreversal_q31(pDst, S_CFFT->fftLen,
|
||||
S_CFFT->bitRevFactor, S_CFFT->pBitRevTable);
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Calculation of RFFT of input */
|
||||
|
||||
/* Complex readix-4 FFT process */
|
||||
arm_radix4_butterfly_q31(pSrc, S_CFFT->fftLen,
|
||||
S_CFFT->pTwiddle, S_CFFT->twidCoefModifier);
|
||||
|
||||
/* Bit reversal process */
|
||||
if(S->bitReverseFlagR == 1u)
|
||||
{
|
||||
arm_bitreversal_q31(pSrc, S_CFFT->fftLen,
|
||||
S_CFFT->bitRevFactor, S_CFFT->pBitRevTable);
|
||||
}
|
||||
|
||||
/* Real FFT core process */
|
||||
arm_split_rfft_q31(pSrc, S->fftLenBy2, S->pTwiddleAReal,
|
||||
S->pTwiddleBReal, pDst, S->twidCoefRModifier);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* @} end of RealFFT group
|
||||
*/
|
||||
|
||||
/**
|
||||
* @brief Core Real FFT process
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[in] fftLen length of FFT.
|
||||
* @param[in] *pATable points to the twiddle Coef A buffer.
|
||||
* @param[in] *pBTable points to the twiddle Coef B buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_split_rfft_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pATable,
|
||||
q31_t * pBTable,
|
||||
q31_t * pDst,
|
||||
uint32_t modifier)
|
||||
{
|
||||
uint32_t i; /* Loop Counter */
|
||||
q31_t outR, outI; /* Temporary variables for output */
|
||||
q31_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */
|
||||
q31_t CoefA1, CoefA2, CoefB1; /* Temporary variables for twiddle coefficients */
|
||||
q31_t *pOut1 = &pDst[2], *pOut2 = &pDst[(4u * fftLen) - 1u];
|
||||
q31_t *pIn1 = &pSrc[2], *pIn2 = &pSrc[(2u * fftLen) - 1u];
|
||||
|
||||
/* Init coefficient pointers */
|
||||
pCoefA = &pATable[modifier * 2u];
|
||||
pCoefB = &pBTable[modifier * 2u];
|
||||
|
||||
i = fftLen - 1u;
|
||||
|
||||
while(i > 0u)
|
||||
{
|
||||
/*
|
||||
outR = (pSrc[2 * i] * pATable[2 * i] - pSrc[2 * i + 1] * pATable[2 * i + 1]
|
||||
+ pSrc[2 * n - 2 * i] * pBTable[2 * i] +
|
||||
pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
*/
|
||||
|
||||
/* outI = (pIn[2 * i + 1] * pATable[2 * i] + pIn[2 * i] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]); */
|
||||
|
||||
CoefA1 = *pCoefA++;
|
||||
CoefA2 = *pCoefA;
|
||||
|
||||
/* outR = (pSrc[2 * i] * pATable[2 * i] */
|
||||
outR = ((int32_t) (((q63_t) * pIn1 * CoefA1) >> 32));
|
||||
|
||||
/* outI = pIn[2 * i] * pATable[2 * i + 1] */
|
||||
outI = ((int32_t) (((q63_t) * pIn1++ * CoefA2) >> 32));
|
||||
|
||||
/* - pSrc[2 * i + 1] * pATable[2 * i + 1] */
|
||||
outR =
|
||||
(q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn1 * (-CoefA2))) >> 32);
|
||||
|
||||
/* (pIn[2 * i + 1] * pATable[2 * i] */
|
||||
outI =
|
||||
(q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn1++ * (CoefA1))) >> 32);
|
||||
|
||||
/* pSrc[2 * n - 2 * i] * pBTable[2 * i] */
|
||||
outR =
|
||||
(q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (-CoefA2))) >> 32);
|
||||
CoefB1 = *pCoefB;
|
||||
|
||||
/* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] */
|
||||
outI =
|
||||
(q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn2-- * (-CoefB1))) >> 32);
|
||||
|
||||
/* pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1] */
|
||||
outR =
|
||||
(q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (CoefB1))) >> 32);
|
||||
|
||||
/* pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */
|
||||
outI =
|
||||
(q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn2-- * (-CoefA2))) >> 32);
|
||||
|
||||
/* write output */
|
||||
*pOut1++ = (outR << 1u);
|
||||
*pOut1++ = (outI << 1u);
|
||||
|
||||
/* write complex conjugate output */
|
||||
*pOut2-- = -(outI << 1u);
|
||||
*pOut2-- = (outR << 1u);
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (modifier * 2u);
|
||||
pCoefA = pCoefA + ((modifier * 2u) - 1u);
|
||||
|
||||
i--;
|
||||
|
||||
}
|
||||
|
||||
pDst[2u * fftLen] = pSrc[0] - pSrc[1];
|
||||
pDst[(2u * fftLen) + 1u] = 0;
|
||||
|
||||
pDst[0] = pSrc[0] + pSrc[1];
|
||||
pDst[1] = 0;
|
||||
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* @brief Core Real IFFT process
|
||||
* @param[in] *pSrc points to the input buffer.
|
||||
* @param[in] fftLen length of FFT.
|
||||
* @param[in] *pATable points to the twiddle Coef A buffer.
|
||||
* @param[in] *pBTable points to the twiddle Coef B buffer.
|
||||
* @param[out] *pDst points to the output buffer.
|
||||
* @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
void arm_split_rifft_q31(
|
||||
q31_t * pSrc,
|
||||
uint32_t fftLen,
|
||||
q31_t * pATable,
|
||||
q31_t * pBTable,
|
||||
q31_t * pDst,
|
||||
uint32_t modifier)
|
||||
{
|
||||
q31_t outR, outI; /* Temporary variables for output */
|
||||
q31_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */
|
||||
q31_t CoefA1, CoefA2, CoefB1; /* Temporary variables for twiddle coefficients */
|
||||
q31_t *pIn1 = &pSrc[0], *pIn2 = &pSrc[(2u * fftLen) + 1u];
|
||||
|
||||
pCoefA = &pATable[0];
|
||||
pCoefB = &pBTable[0];
|
||||
|
||||
while(fftLen > 0u)
|
||||
{
|
||||
/*
|
||||
outR = (pIn[2 * i] * pATable[2 * i] + pIn[2 * i + 1] * pATable[2 * i + 1] +
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1]);
|
||||
|
||||
outI = (pIn[2 * i + 1] * pATable[2 * i] - pIn[2 * i] * pATable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i] * pBTable[2 * i + 1] -
|
||||
pIn[2 * n - 2 * i + 1] * pBTable[2 * i]);
|
||||
|
||||
*/
|
||||
CoefA1 = *pCoefA++;
|
||||
CoefA2 = *pCoefA;
|
||||
|
||||
/* outR = (pIn[2 * i] * pATable[2 * i] */
|
||||
outR = ((int32_t) (((q63_t) * pIn1 * CoefA1) >> 32));
|
||||
|
||||
/* - pIn[2 * i] * pATable[2 * i + 1] */
|
||||
outI = -((int32_t) (((q63_t) * pIn1++ * CoefA2) >> 32));
|
||||
|
||||
/* pIn[2 * i + 1] * pATable[2 * i + 1] */
|
||||
outR =
|
||||
(q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn1 * (CoefA2))) >> 32);
|
||||
|
||||
/* pIn[2 * i + 1] * pATable[2 * i] */
|
||||
outI =
|
||||
(q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn1++ * (CoefA1))) >> 32);
|
||||
|
||||
/* pIn[2 * n - 2 * i] * pBTable[2 * i] */
|
||||
outR =
|
||||
(q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (CoefA2))) >> 32);
|
||||
|
||||
CoefB1 = *pCoefB;
|
||||
|
||||
/* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] */
|
||||
outI =
|
||||
(q31_t) ((((q63_t) outI << 32) - ((q63_t) * pIn2-- * (CoefB1))) >> 32);
|
||||
|
||||
/* pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1] */
|
||||
outR =
|
||||
(q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (CoefB1))) >> 32);
|
||||
|
||||
/* pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */
|
||||
outI =
|
||||
(q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn2-- * (CoefA2))) >> 32);
|
||||
|
||||
/* write output */
|
||||
*pDst++ = (outR << 1u);
|
||||
*pDst++ = (outI << 1u);
|
||||
|
||||
/* update coefficient pointer */
|
||||
pCoefB = pCoefB + (modifier * 2u);
|
||||
pCoefA = pCoefA + ((modifier * 2u) - 1u);
|
||||
|
||||
/* Decrement loop count */
|
||||
fftLen--;
|
||||
|
||||
}
|
||||
|
||||
|
||||
}
|
Reference in New Issue
Block a user