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Diffstat (limited to 'Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c')
-rw-r--r--Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c309
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diff --git a/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c
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+++ b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_f32.c
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+/* ----------------------------------------------------------------------
+ * 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--;
+ }
+
+}
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