mbed-os 6.10 versione
cmsis_dsp/TransformFunctions/arm_cfft_radix2_q31.c@2:da51fb522205, 2013-05-30 (annotated)
- Committer:
- emilmont
- Date:
- Thu May 30 17:10:11 2013 +0100
- Revision:
- 2:da51fb522205
- Parent:
- 1:fdd22bb7aa52
- Child:
- 3:7a284390b0ce
Keep "cmsis-dsp" module in synch with its source
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
emilmont | 1:fdd22bb7aa52 | 1 | /* ---------------------------------------------------------------------- |
emilmont | 1:fdd22bb7aa52 | 2 | * Copyright (C) 2010 ARM Limited. All rights reserved. |
emilmont | 1:fdd22bb7aa52 | 3 | * |
emilmont | 1:fdd22bb7aa52 | 4 | * $Date: 15. February 2012 |
emilmont | 2:da51fb522205 | 5 | * $Revision: V1.1.0 |
emilmont | 1:fdd22bb7aa52 | 6 | * |
emilmont | 2:da51fb522205 | 7 | * Project: CMSIS DSP Library |
emilmont | 2:da51fb522205 | 8 | * Title: arm_cfft_radix2_q31.c |
emilmont | 1:fdd22bb7aa52 | 9 | * |
emilmont | 2:da51fb522205 | 10 | * Description: Radix-2 Decimation in Frequency CFFT & CIFFT Fixed point processing function |
emilmont | 1:fdd22bb7aa52 | 11 | * |
emilmont | 1:fdd22bb7aa52 | 12 | * |
emilmont | 1:fdd22bb7aa52 | 13 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
emilmont | 1:fdd22bb7aa52 | 14 | * |
emilmont | 1:fdd22bb7aa52 | 15 | * Version 1.1.0 2012/02/15 |
emilmont | 1:fdd22bb7aa52 | 16 | * Updated with more optimizations, bug fixes and minor API changes. |
emilmont | 1:fdd22bb7aa52 | 17 | * |
emilmont | 1:fdd22bb7aa52 | 18 | * Version 0.0.3 2010/03/10 |
emilmont | 1:fdd22bb7aa52 | 19 | * Initial version |
emilmont | 1:fdd22bb7aa52 | 20 | * -------------------------------------------------------------------- */ |
emilmont | 1:fdd22bb7aa52 | 21 | |
emilmont | 1:fdd22bb7aa52 | 22 | #include "arm_math.h" |
emilmont | 1:fdd22bb7aa52 | 23 | |
emilmont | 1:fdd22bb7aa52 | 24 | /** |
emilmont | 1:fdd22bb7aa52 | 25 | * @ingroup groupTransforms |
emilmont | 1:fdd22bb7aa52 | 26 | */ |
emilmont | 1:fdd22bb7aa52 | 27 | |
emilmont | 1:fdd22bb7aa52 | 28 | /** |
emilmont | 1:fdd22bb7aa52 | 29 | * @defgroup Radix2_CFFT_CIFFT Radix-2 Complex FFT Functions |
emilmont | 1:fdd22bb7aa52 | 30 | * |
emilmont | 1:fdd22bb7aa52 | 31 | * \par |
emilmont | 1:fdd22bb7aa52 | 32 | * 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). |
emilmont | 1:fdd22bb7aa52 | 33 | * Computational complexity of CFFT reduces drastically when compared to DFT. |
emilmont | 1:fdd22bb7aa52 | 34 | */ |
emilmont | 1:fdd22bb7aa52 | 35 | |
emilmont | 1:fdd22bb7aa52 | 36 | |
emilmont | 1:fdd22bb7aa52 | 37 | /** |
emilmont | 1:fdd22bb7aa52 | 38 | * @addtogroup Radix2_CFFT_CIFFT |
emilmont | 1:fdd22bb7aa52 | 39 | * @{ |
emilmont | 1:fdd22bb7aa52 | 40 | */ |
emilmont | 1:fdd22bb7aa52 | 41 | |
emilmont | 1:fdd22bb7aa52 | 42 | /** |
emilmont | 1:fdd22bb7aa52 | 43 | * @details |
emilmont | 1:fdd22bb7aa52 | 44 | * @brief Processing function for the fixed-point CFFT/CIFFT. |
emilmont | 1:fdd22bb7aa52 | 45 | * @param[in] *S points to an instance of the fixed-point CFFT/CIFFT structure. |
emilmont | 1:fdd22bb7aa52 | 46 | * @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place. |
emilmont | 1:fdd22bb7aa52 | 47 | * @return none. |
emilmont | 1:fdd22bb7aa52 | 48 | */ |
emilmont | 1:fdd22bb7aa52 | 49 | |
emilmont | 1:fdd22bb7aa52 | 50 | void arm_cfft_radix2_q31( |
emilmont | 1:fdd22bb7aa52 | 51 | const arm_cfft_radix2_instance_q31 * S, |
emilmont | 1:fdd22bb7aa52 | 52 | q31_t * pSrc) |
emilmont | 1:fdd22bb7aa52 | 53 | { |
emilmont | 1:fdd22bb7aa52 | 54 | |
emilmont | 1:fdd22bb7aa52 | 55 | if(S->ifftFlag == 1u) |
emilmont | 1:fdd22bb7aa52 | 56 | { |
emilmont | 1:fdd22bb7aa52 | 57 | arm_radix2_butterfly_inverse_q31(pSrc, S->fftLen, |
emilmont | 1:fdd22bb7aa52 | 58 | S->pTwiddle, S->twidCoefModifier); |
emilmont | 1:fdd22bb7aa52 | 59 | } |
emilmont | 1:fdd22bb7aa52 | 60 | else |
emilmont | 1:fdd22bb7aa52 | 61 | { |
emilmont | 1:fdd22bb7aa52 | 62 | arm_radix2_butterfly_q31(pSrc, S->fftLen, |
emilmont | 1:fdd22bb7aa52 | 63 | S->pTwiddle, S->twidCoefModifier); |
emilmont | 1:fdd22bb7aa52 | 64 | } |
emilmont | 1:fdd22bb7aa52 | 65 | |
emilmont | 1:fdd22bb7aa52 | 66 | arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable); |
emilmont | 1:fdd22bb7aa52 | 67 | } |
emilmont | 1:fdd22bb7aa52 | 68 | |
emilmont | 1:fdd22bb7aa52 | 69 | /** |
emilmont | 1:fdd22bb7aa52 | 70 | * @} end of Radix2_CFFT_CIFFT group |
emilmont | 1:fdd22bb7aa52 | 71 | */ |
emilmont | 1:fdd22bb7aa52 | 72 | |
emilmont | 1:fdd22bb7aa52 | 73 | void arm_radix2_butterfly_q31( |
emilmont | 1:fdd22bb7aa52 | 74 | q31_t * pSrc, |
emilmont | 1:fdd22bb7aa52 | 75 | uint32_t fftLen, |
emilmont | 1:fdd22bb7aa52 | 76 | q31_t * pCoef, |
emilmont | 1:fdd22bb7aa52 | 77 | uint16_t twidCoefModifier) |
emilmont | 1:fdd22bb7aa52 | 78 | { |
emilmont | 1:fdd22bb7aa52 | 79 | |
emilmont | 1:fdd22bb7aa52 | 80 | int i, j, k, l; |
emilmont | 1:fdd22bb7aa52 | 81 | int n1, n2, ia; |
emilmont | 1:fdd22bb7aa52 | 82 | q31_t xt, yt, cosVal, sinVal; |
emilmont | 1:fdd22bb7aa52 | 83 | |
emilmont | 1:fdd22bb7aa52 | 84 | //N = fftLen; |
emilmont | 1:fdd22bb7aa52 | 85 | n2 = fftLen; |
emilmont | 1:fdd22bb7aa52 | 86 | |
emilmont | 1:fdd22bb7aa52 | 87 | n1 = n2; |
emilmont | 1:fdd22bb7aa52 | 88 | n2 = n2 >> 1; |
emilmont | 1:fdd22bb7aa52 | 89 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 90 | |
emilmont | 1:fdd22bb7aa52 | 91 | // loop for groups |
emilmont | 1:fdd22bb7aa52 | 92 | for (i = 0; i < n2; i++) |
emilmont | 1:fdd22bb7aa52 | 93 | { |
emilmont | 1:fdd22bb7aa52 | 94 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 95 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 96 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 97 | |
emilmont | 1:fdd22bb7aa52 | 98 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 99 | xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u); |
emilmont | 1:fdd22bb7aa52 | 100 | pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 101 | |
emilmont | 1:fdd22bb7aa52 | 102 | yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u); |
emilmont | 1:fdd22bb7aa52 | 103 | pSrc[2 * i + 1] = |
emilmont | 1:fdd22bb7aa52 | 104 | ((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 105 | |
emilmont | 1:fdd22bb7aa52 | 106 | pSrc[2u * l] = (((int32_t) (((q63_t) xt * cosVal) >> 32)) + |
emilmont | 1:fdd22bb7aa52 | 107 | ((int32_t) (((q63_t) yt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 108 | |
emilmont | 1:fdd22bb7aa52 | 109 | pSrc[2u * l + 1u] = (((int32_t) (((q63_t) yt * cosVal) >> 32)) - |
emilmont | 1:fdd22bb7aa52 | 110 | ((int32_t) (((q63_t) xt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 111 | |
emilmont | 1:fdd22bb7aa52 | 112 | } // groups loop end |
emilmont | 1:fdd22bb7aa52 | 113 | |
emilmont | 1:fdd22bb7aa52 | 114 | twidCoefModifier = twidCoefModifier << 1u; |
emilmont | 1:fdd22bb7aa52 | 115 | |
emilmont | 1:fdd22bb7aa52 | 116 | // loop for stage |
emilmont | 1:fdd22bb7aa52 | 117 | for (k = fftLen / 2; k > 2; k = k >> 1) |
emilmont | 1:fdd22bb7aa52 | 118 | { |
emilmont | 1:fdd22bb7aa52 | 119 | n1 = n2; |
emilmont | 1:fdd22bb7aa52 | 120 | n2 = n2 >> 1; |
emilmont | 1:fdd22bb7aa52 | 121 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 122 | |
emilmont | 1:fdd22bb7aa52 | 123 | // loop for groups |
emilmont | 1:fdd22bb7aa52 | 124 | for (j = 0; j < n2; j++) |
emilmont | 1:fdd22bb7aa52 | 125 | { |
emilmont | 1:fdd22bb7aa52 | 126 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 127 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 128 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 129 | |
emilmont | 1:fdd22bb7aa52 | 130 | // loop for butterfly |
emilmont | 1:fdd22bb7aa52 | 131 | for (i = j; i < fftLen; i += n1) |
emilmont | 1:fdd22bb7aa52 | 132 | { |
emilmont | 1:fdd22bb7aa52 | 133 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 134 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emilmont | 1:fdd22bb7aa52 | 135 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 136 | |
emilmont | 1:fdd22bb7aa52 | 137 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emilmont | 1:fdd22bb7aa52 | 138 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 139 | |
emilmont | 1:fdd22bb7aa52 | 140 | pSrc[2u * l] = (((int32_t) (((q63_t) xt * cosVal) >> 32)) + |
emilmont | 1:fdd22bb7aa52 | 141 | ((int32_t) (((q63_t) yt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 142 | |
emilmont | 1:fdd22bb7aa52 | 143 | pSrc[2u * l + 1u] = (((int32_t) (((q63_t) yt * cosVal) >> 32)) - |
emilmont | 1:fdd22bb7aa52 | 144 | ((int32_t) (((q63_t) xt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 145 | |
emilmont | 1:fdd22bb7aa52 | 146 | } // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 147 | |
emilmont | 1:fdd22bb7aa52 | 148 | } // groups loop end |
emilmont | 1:fdd22bb7aa52 | 149 | |
emilmont | 1:fdd22bb7aa52 | 150 | twidCoefModifier = twidCoefModifier << 1u; |
emilmont | 1:fdd22bb7aa52 | 151 | } // stages loop end |
emilmont | 1:fdd22bb7aa52 | 152 | |
emilmont | 1:fdd22bb7aa52 | 153 | n1 = n2; |
emilmont | 1:fdd22bb7aa52 | 154 | n2 = n2 >> 1; |
emilmont | 1:fdd22bb7aa52 | 155 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 156 | |
emilmont | 1:fdd22bb7aa52 | 157 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 158 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 159 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 160 | |
emilmont | 1:fdd22bb7aa52 | 161 | // loop for butterfly |
emilmont | 1:fdd22bb7aa52 | 162 | for (i = 0; i < fftLen; i += n1) |
emilmont | 1:fdd22bb7aa52 | 163 | { |
emilmont | 1:fdd22bb7aa52 | 164 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 165 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emilmont | 1:fdd22bb7aa52 | 166 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 167 | |
emilmont | 1:fdd22bb7aa52 | 168 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emilmont | 1:fdd22bb7aa52 | 169 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 170 | |
emilmont | 1:fdd22bb7aa52 | 171 | pSrc[2u * l] = xt; |
emilmont | 1:fdd22bb7aa52 | 172 | |
emilmont | 1:fdd22bb7aa52 | 173 | pSrc[2u * l + 1u] = yt; |
emilmont | 1:fdd22bb7aa52 | 174 | |
emilmont | 1:fdd22bb7aa52 | 175 | i += n1; |
emilmont | 1:fdd22bb7aa52 | 176 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 177 | |
emilmont | 1:fdd22bb7aa52 | 178 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emilmont | 1:fdd22bb7aa52 | 179 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 180 | |
emilmont | 1:fdd22bb7aa52 | 181 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emilmont | 1:fdd22bb7aa52 | 182 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 183 | |
emilmont | 1:fdd22bb7aa52 | 184 | pSrc[2u * l] = xt; |
emilmont | 1:fdd22bb7aa52 | 185 | |
emilmont | 1:fdd22bb7aa52 | 186 | pSrc[2u * l + 1u] = yt; |
emilmont | 1:fdd22bb7aa52 | 187 | |
emilmont | 1:fdd22bb7aa52 | 188 | } // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 189 | |
emilmont | 1:fdd22bb7aa52 | 190 | } |
emilmont | 1:fdd22bb7aa52 | 191 | |
emilmont | 1:fdd22bb7aa52 | 192 | |
emilmont | 1:fdd22bb7aa52 | 193 | void arm_radix2_butterfly_inverse_q31( |
emilmont | 1:fdd22bb7aa52 | 194 | q31_t * pSrc, |
emilmont | 1:fdd22bb7aa52 | 195 | uint32_t fftLen, |
emilmont | 1:fdd22bb7aa52 | 196 | q31_t * pCoef, |
emilmont | 1:fdd22bb7aa52 | 197 | uint16_t twidCoefModifier) |
emilmont | 1:fdd22bb7aa52 | 198 | { |
emilmont | 1:fdd22bb7aa52 | 199 | |
emilmont | 1:fdd22bb7aa52 | 200 | int i, j, k, l; |
emilmont | 1:fdd22bb7aa52 | 201 | int n1, n2, ia; |
emilmont | 1:fdd22bb7aa52 | 202 | q31_t xt, yt, cosVal, sinVal; |
emilmont | 1:fdd22bb7aa52 | 203 | |
emilmont | 1:fdd22bb7aa52 | 204 | //N = fftLen; |
emilmont | 1:fdd22bb7aa52 | 205 | n2 = fftLen; |
emilmont | 1:fdd22bb7aa52 | 206 | |
emilmont | 1:fdd22bb7aa52 | 207 | n1 = n2; |
emilmont | 1:fdd22bb7aa52 | 208 | n2 = n2 >> 1; |
emilmont | 1:fdd22bb7aa52 | 209 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 210 | |
emilmont | 1:fdd22bb7aa52 | 211 | // loop for groups |
emilmont | 1:fdd22bb7aa52 | 212 | for (i = 0; i < n2; i++) |
emilmont | 1:fdd22bb7aa52 | 213 | { |
emilmont | 1:fdd22bb7aa52 | 214 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 215 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 216 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 217 | |
emilmont | 1:fdd22bb7aa52 | 218 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 219 | xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u); |
emilmont | 1:fdd22bb7aa52 | 220 | pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 221 | |
emilmont | 1:fdd22bb7aa52 | 222 | yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u); |
emilmont | 1:fdd22bb7aa52 | 223 | pSrc[2 * i + 1] = |
emilmont | 1:fdd22bb7aa52 | 224 | ((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 225 | |
emilmont | 1:fdd22bb7aa52 | 226 | pSrc[2u * l] = (((int32_t) (((q63_t) xt * cosVal) >> 32)) - |
emilmont | 1:fdd22bb7aa52 | 227 | ((int32_t) (((q63_t) yt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 228 | |
emilmont | 1:fdd22bb7aa52 | 229 | pSrc[2u * l + 1u] = (((int32_t) (((q63_t) yt * cosVal) >> 32)) + |
emilmont | 1:fdd22bb7aa52 | 230 | ((int32_t) (((q63_t) xt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 231 | |
emilmont | 1:fdd22bb7aa52 | 232 | } // groups loop end |
emilmont | 1:fdd22bb7aa52 | 233 | |
emilmont | 1:fdd22bb7aa52 | 234 | twidCoefModifier = twidCoefModifier << 1u; |
emilmont | 1:fdd22bb7aa52 | 235 | |
emilmont | 1:fdd22bb7aa52 | 236 | // loop for stage |
emilmont | 1:fdd22bb7aa52 | 237 | for (k = fftLen / 2; k > 2; k = k >> 1) |
emilmont | 1:fdd22bb7aa52 | 238 | { |
emilmont | 1:fdd22bb7aa52 | 239 | n1 = n2; |
emilmont | 1:fdd22bb7aa52 | 240 | n2 = n2 >> 1; |
emilmont | 1:fdd22bb7aa52 | 241 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 242 | |
emilmont | 1:fdd22bb7aa52 | 243 | // loop for groups |
emilmont | 1:fdd22bb7aa52 | 244 | for (j = 0; j < n2; j++) |
emilmont | 1:fdd22bb7aa52 | 245 | { |
emilmont | 1:fdd22bb7aa52 | 246 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 247 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 248 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 249 | |
emilmont | 1:fdd22bb7aa52 | 250 | // loop for butterfly |
emilmont | 1:fdd22bb7aa52 | 251 | for (i = j; i < fftLen; i += n1) |
emilmont | 1:fdd22bb7aa52 | 252 | { |
emilmont | 1:fdd22bb7aa52 | 253 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 254 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emilmont | 1:fdd22bb7aa52 | 255 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 256 | |
emilmont | 1:fdd22bb7aa52 | 257 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emilmont | 1:fdd22bb7aa52 | 258 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 259 | |
emilmont | 1:fdd22bb7aa52 | 260 | pSrc[2u * l] = (((int32_t) (((q63_t) xt * cosVal) >> 32)) - |
emilmont | 1:fdd22bb7aa52 | 261 | ((int32_t) (((q63_t) yt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 262 | |
emilmont | 1:fdd22bb7aa52 | 263 | pSrc[2u * l + 1u] = (((int32_t) (((q63_t) yt * cosVal) >> 32)) + |
emilmont | 1:fdd22bb7aa52 | 264 | ((int32_t) (((q63_t) xt * sinVal) >> 32))); |
emilmont | 1:fdd22bb7aa52 | 265 | |
emilmont | 1:fdd22bb7aa52 | 266 | } // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 267 | |
emilmont | 1:fdd22bb7aa52 | 268 | } // groups loop end |
emilmont | 1:fdd22bb7aa52 | 269 | |
emilmont | 1:fdd22bb7aa52 | 270 | twidCoefModifier = twidCoefModifier << 1u; |
emilmont | 1:fdd22bb7aa52 | 271 | } // stages loop end |
emilmont | 1:fdd22bb7aa52 | 272 | |
emilmont | 1:fdd22bb7aa52 | 273 | n1 = n2; |
emilmont | 1:fdd22bb7aa52 | 274 | n2 = n2 >> 1; |
emilmont | 1:fdd22bb7aa52 | 275 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 276 | |
emilmont | 1:fdd22bb7aa52 | 277 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 278 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 279 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 280 | |
emilmont | 1:fdd22bb7aa52 | 281 | // loop for butterfly |
emilmont | 1:fdd22bb7aa52 | 282 | for (i = 0; i < fftLen; i += n1) |
emilmont | 1:fdd22bb7aa52 | 283 | { |
emilmont | 1:fdd22bb7aa52 | 284 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 285 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emilmont | 1:fdd22bb7aa52 | 286 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 287 | |
emilmont | 1:fdd22bb7aa52 | 288 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emilmont | 1:fdd22bb7aa52 | 289 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 290 | |
emilmont | 1:fdd22bb7aa52 | 291 | pSrc[2u * l] = xt; |
emilmont | 1:fdd22bb7aa52 | 292 | |
emilmont | 1:fdd22bb7aa52 | 293 | pSrc[2u * l + 1u] = yt; |
emilmont | 1:fdd22bb7aa52 | 294 | |
emilmont | 1:fdd22bb7aa52 | 295 | i += n1; |
emilmont | 1:fdd22bb7aa52 | 296 | l = i + n2; |
emilmont | 1:fdd22bb7aa52 | 297 | |
emilmont | 1:fdd22bb7aa52 | 298 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emilmont | 1:fdd22bb7aa52 | 299 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 300 | |
emilmont | 1:fdd22bb7aa52 | 301 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emilmont | 1:fdd22bb7aa52 | 302 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 303 | |
emilmont | 1:fdd22bb7aa52 | 304 | pSrc[2u * l] = xt; |
emilmont | 1:fdd22bb7aa52 | 305 | |
emilmont | 1:fdd22bb7aa52 | 306 | pSrc[2u * l + 1u] = yt; |
emilmont | 1:fdd22bb7aa52 | 307 | |
emilmont | 1:fdd22bb7aa52 | 308 | } // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 309 | |
emilmont | 1:fdd22bb7aa52 | 310 | } |