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Diffstat (limited to 'tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_f32.c')
-rw-r--r-- | tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_f32.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_f32.c b/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_f32.c new file mode 100644 index 0000000000..bb3f35dd41 --- /dev/null +++ b/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_f32.c @@ -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--; + } + +} |