From 86608c6770cf08c138a2bdab5855072f64be09ef Mon Sep 17 00:00:00 2001 From: joshua Date: Sat, 30 Dec 2023 23:54:31 -0500 Subject: initial commit --- .../DSP/Source/TransformFunctions/arm_rfft_f32.c | 309 +++++++++++++++++++++ 1 file changed, 309 insertions(+) create mode 100644 Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c (limited to 'Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c') diff --git a/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c new file mode 100644 index 0000000..2ad336d --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c @@ -0,0 +1,309 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_rfft_f32.c + * Description: RFFT & RIFFT Floating point process function + * + * $Date: 18. March 2019 + * $Revision: V1.6.0 + * + * Target Processor: Cortex-M cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "arm_math.h" + +/* ---------------------------------------------------------------------- + * Internal functions prototypes + * -------------------------------------------------------------------- */ + +extern void arm_radix4_butterfly_f32( + float32_t * pSrc, + uint16_t fftLen, + const float32_t * pCoef, + uint16_t twidCoefModifier); + +extern void arm_radix4_butterfly_inverse_f32( + float32_t * pSrc, + uint16_t fftLen, + const float32_t * pCoef, + uint16_t twidCoefModifier, + float32_t onebyfftLen); + +extern void arm_bitreversal_f32( + float32_t * pSrc, + uint16_t fftSize, + uint16_t bitRevFactor, + const uint16_t * pBitRevTab); + +void arm_split_rfft_f32( + float32_t * pSrc, + uint32_t fftLen, + const float32_t * pATable, + const float32_t * pBTable, + float32_t * pDst, + uint32_t modifier); + +void arm_split_rifft_f32( + float32_t * pSrc, + uint32_t fftLen, + const float32_t * pATable, + const float32_t * pBTable, + float32_t * pDst, + uint32_t modifier); + +/** + @ingroup groupTransforms + */ + +/** + @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 input buffer + @param[in] fftLen length of FFT + @param[in] pATable points to twiddle Coef A buffer + @param[in] pBTable points to twiddle Coef B buffer + @param[out] pDst points to 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, + const float32_t * pATable, + const float32_t * pBTable, + float32_t * pDst, + uint32_t modifier) +{ + uint32_t i; /* Loop Counter */ + float32_t outR, outI; /* Temporary variables for output */ + const 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 * 2]; + pCoefB = &pBTable[modifier * 2]; + + 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 input buffer + @param[in] fftLen length of FFT + @param[in] pATable points to twiddle Coef A buffer + @param[in] pBTable points to twiddle Coef B buffer + @param[out] pDst points to 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, + const float32_t * pATable, + const float32_t * pBTable, + float32_t * pDst, + uint32_t modifier) +{ + float32_t outR, outI; /* Temporary variables for output */ + const 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 * 2); + pCoefA = pCoefA + (modifier * 2 - 1); + + /* Decrement loop count */ + fftLen--; + } + +} -- cgit v1.2.3