diff options
Diffstat (limited to 'DSP/Source/TransformFunctions/arm_rfft_f32.c')
| -rw-r--r-- | DSP/Source/TransformFunctions/arm_rfft_f32.c | 281 |
1 files changed, 136 insertions, 145 deletions
diff --git a/DSP/Source/TransformFunctions/arm_rfft_f32.c b/DSP/Source/TransformFunctions/arm_rfft_f32.c index a1bd81b..b5d0a66 100644 --- a/DSP/Source/TransformFunctions/arm_rfft_f32.c +++ b/DSP/Source/TransformFunctions/arm_rfft_f32.c @@ -3,13 +3,13 @@ * Title: arm_rfft_f32.c * Description: RFFT & RIFFT Floating point process function * - * $Date: 27. January 2017 - * $Revision: V.1.5.1 + * $Date: 18. March 2019 + * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* - * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * @@ -33,159 +33,149 @@ * -------------------------------------------------------------------- */ extern void arm_radix4_butterfly_f32( - float32_t * pSrc, - uint16_t fftLen, - float32_t * pCoef, - uint16_t twidCoefModifier); + 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, - float32_t * pCoef, - uint16_t twidCoefModifier, - float32_t onebyfftLen); + 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, - uint16_t * pBitRevTab); + float32_t * pSrc, + uint16_t fftSize, + uint16_t bitRevFactor, + const uint16_t * pBitRevTab); void arm_split_rfft_f32( - float32_t * pSrc, - uint32_t fftLen, - float32_t * pATable, - float32_t * pBTable, - float32_t * pDst, - uint32_t modifier); + 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, - float32_t * pATable, - float32_t * pBTable, - float32_t * pDst, - uint32_t modifier); + float32_t * pSrc, + uint32_t fftLen, + const float32_t * pATable, + const float32_t * pBTable, + float32_t * pDst, + uint32_t modifier); /** -* @ingroup groupTransforms -*/ + @ingroup groupTransforms + */ /** - * @addtogroup RealFFT - * @{ + @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. + @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) + 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); + /* 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); + /* 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); + 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); + 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); + 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); + arm_split_rfft_f32 (pSrc, S->fftLenBy2, S->pTwiddleAReal, S->pTwiddleBReal, pDst, S->twidCoefRModifier); } } /** - * @} end of RealFFT group - */ + @} 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. + @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, - float32_t * pATable, - float32_t * pBTable, - float32_t * pDst, - uint32_t modifier) + 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 */ - 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 */ + 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 * 2U]; - pCoefB = &pBTable[modifier * 2U]; + 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]); */ + /* + 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++; @@ -238,81 +228,82 @@ void arm_split_rfft_f32( /** - * @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. + @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, - float32_t * pATable, - float32_t * pBTable, - float32_t * pDst, - uint32_t modifier) + 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 */ - 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]; + 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]); + /* + 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]); + 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; - CoefA1 = *pCoefA++; - CoefA2 = *pCoefA; - - /* outR = (pSrc[2 * i] * CoefA1 */ - outR = *pSrc1 * CoefA1; + /* outR = (pSrc[2 * i] * CoefA1 */ + outR = *pSrc1 * CoefA1; - /* - pSrc[2 * i] * CoefA2 */ - outI = -(*pSrc1++) * CoefA2; + /* - 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] + pSrc[2 * fftLen - 2 * i + 1]) * CoefA2 */ + outR += (*pSrc1 + *pSrc2) * CoefA2; - /* pSrc[2 * i + 1] * CoefA1 */ - outI += (*pSrc1++) * CoefA1; + /* pSrc[2 * i + 1] * CoefA1 */ + outI += (*pSrc1++) * CoefA1; - CoefB1 = *pCoefB; + CoefB1 = *pCoefB; - /* - pSrc[2 * fftLen - 2 * i + 1] * CoefB1 */ - outI -= *pSrc2-- * CoefB1; + /* - pSrc[2 * fftLen - 2 * i + 1] * CoefB1 */ + outI -= *pSrc2-- * CoefB1; - /* pSrc[2 * fftLen - 2 * i] * CoefB1 */ - outR += *pSrc2 * CoefB1; + /* pSrc[2 * fftLen - 2 * i] * CoefB1 */ + outR += *pSrc2 * CoefB1; - /* pSrc[2 * fftLen - 2 * i] * CoefA2 */ - outI += *pSrc2-- * CoefA2; + /* pSrc[2 * fftLen - 2 * i] * CoefA2 */ + outI += *pSrc2-- * CoefA2; - /* write output */ - *pDst++ = outR; - *pDst++ = outI; + /* write output */ + *pDst++ = outR; + *pDst++ = outI; - /* update coefficient pointer */ - pCoefB = pCoefB + (modifier * 2U); - pCoefA = pCoefA + ((modifier * 2U) - 1U); + /* update coefficient pointer */ + pCoefB = pCoefB + (modifier * 2); + pCoefA = pCoefA + (modifier * 2 - 1); - /* Decrement loop count */ - fftLen--; + /* Decrement loop count */ + fftLen--; } } |