mbed-os 6.10 versione
cmsis_dsp/TransformFunctions/arm_cfft_radix2_q31.c@3:7a284390b0ce, 2013-11-08 (annotated)
- Committer:
- mbed_official
- Date:
- Fri Nov 08 13:45:10 2013 +0000
- Revision:
- 3:7a284390b0ce
- Parent:
- 2:da51fb522205
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
emilmont | 1:fdd22bb7aa52 | 1 | /* ---------------------------------------------------------------------- |
mbed_official | 3:7a284390b0ce | 2 | * Copyright (C) 2010-2013 ARM Limited. All rights reserved. |
emilmont | 1:fdd22bb7aa52 | 3 | * |
mbed_official | 3:7a284390b0ce | 4 | * $Date: 17. January 2013 |
mbed_official | 3:7a284390b0ce | 5 | * $Revision: V1.4.1 |
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 | * |
mbed_official | 3:7a284390b0ce | 15 | * Redistribution and use in source and binary forms, with or without |
mbed_official | 3:7a284390b0ce | 16 | * modification, are permitted provided that the following conditions |
mbed_official | 3:7a284390b0ce | 17 | * are met: |
mbed_official | 3:7a284390b0ce | 18 | * - Redistributions of source code must retain the above copyright |
mbed_official | 3:7a284390b0ce | 19 | * notice, this list of conditions and the following disclaimer. |
mbed_official | 3:7a284390b0ce | 20 | * - Redistributions in binary form must reproduce the above copyright |
mbed_official | 3:7a284390b0ce | 21 | * notice, this list of conditions and the following disclaimer in |
mbed_official | 3:7a284390b0ce | 22 | * the documentation and/or other materials provided with the |
mbed_official | 3:7a284390b0ce | 23 | * distribution. |
mbed_official | 3:7a284390b0ce | 24 | * - Neither the name of ARM LIMITED nor the names of its contributors |
mbed_official | 3:7a284390b0ce | 25 | * may be used to endorse or promote products derived from this |
mbed_official | 3:7a284390b0ce | 26 | * software without specific prior written permission. |
mbed_official | 3:7a284390b0ce | 27 | * |
mbed_official | 3:7a284390b0ce | 28 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
mbed_official | 3:7a284390b0ce | 29 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
mbed_official | 3:7a284390b0ce | 30 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
mbed_official | 3:7a284390b0ce | 31 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
mbed_official | 3:7a284390b0ce | 32 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
mbed_official | 3:7a284390b0ce | 33 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
mbed_official | 3:7a284390b0ce | 34 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
mbed_official | 3:7a284390b0ce | 35 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
mbed_official | 3:7a284390b0ce | 36 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
mbed_official | 3:7a284390b0ce | 37 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
mbed_official | 3:7a284390b0ce | 38 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
mbed_official | 3:7a284390b0ce | 39 | * POSSIBILITY OF SUCH DAMAGE. |
emilmont | 1:fdd22bb7aa52 | 40 | * -------------------------------------------------------------------- */ |
emilmont | 1:fdd22bb7aa52 | 41 | |
emilmont | 1:fdd22bb7aa52 | 42 | #include "arm_math.h" |
emilmont | 1:fdd22bb7aa52 | 43 | |
emilmont | 1:fdd22bb7aa52 | 44 | void arm_radix2_butterfly_q31( |
emilmont | 1:fdd22bb7aa52 | 45 | q31_t * pSrc, |
emilmont | 1:fdd22bb7aa52 | 46 | uint32_t fftLen, |
emilmont | 1:fdd22bb7aa52 | 47 | q31_t * pCoef, |
mbed_official | 3:7a284390b0ce | 48 | uint16_t twidCoefModifier); |
mbed_official | 3:7a284390b0ce | 49 | |
mbed_official | 3:7a284390b0ce | 50 | void arm_radix2_butterfly_inverse_q31( |
mbed_official | 3:7a284390b0ce | 51 | q31_t * pSrc, |
mbed_official | 3:7a284390b0ce | 52 | uint32_t fftLen, |
mbed_official | 3:7a284390b0ce | 53 | q31_t * pCoef, |
mbed_official | 3:7a284390b0ce | 54 | uint16_t twidCoefModifier); |
mbed_official | 3:7a284390b0ce | 55 | |
mbed_official | 3:7a284390b0ce | 56 | void arm_bitreversal_q31( |
mbed_official | 3:7a284390b0ce | 57 | q31_t * pSrc, |
mbed_official | 3:7a284390b0ce | 58 | uint32_t fftLen, |
mbed_official | 3:7a284390b0ce | 59 | uint16_t bitRevFactor, |
mbed_official | 3:7a284390b0ce | 60 | uint16_t * pBitRevTab); |
mbed_official | 3:7a284390b0ce | 61 | |
mbed_official | 3:7a284390b0ce | 62 | /** |
mbed_official | 3:7a284390b0ce | 63 | * @ingroup groupTransforms |
mbed_official | 3:7a284390b0ce | 64 | */ |
mbed_official | 3:7a284390b0ce | 65 | |
mbed_official | 3:7a284390b0ce | 66 | /** |
mbed_official | 3:7a284390b0ce | 67 | * @addtogroup ComplexFFT |
mbed_official | 3:7a284390b0ce | 68 | * @{ |
mbed_official | 3:7a284390b0ce | 69 | */ |
mbed_official | 3:7a284390b0ce | 70 | |
mbed_official | 3:7a284390b0ce | 71 | /** |
mbed_official | 3:7a284390b0ce | 72 | * @details |
mbed_official | 3:7a284390b0ce | 73 | * @brief Processing function for the fixed-point CFFT/CIFFT. |
mbed_official | 3:7a284390b0ce | 74 | * @param[in] *S points to an instance of the fixed-point CFFT/CIFFT structure. |
mbed_official | 3:7a284390b0ce | 75 | * @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place. |
mbed_official | 3:7a284390b0ce | 76 | * @return none. |
mbed_official | 3:7a284390b0ce | 77 | */ |
mbed_official | 3:7a284390b0ce | 78 | |
mbed_official | 3:7a284390b0ce | 79 | void arm_cfft_radix2_q31( |
mbed_official | 3:7a284390b0ce | 80 | const arm_cfft_radix2_instance_q31 * S, |
mbed_official | 3:7a284390b0ce | 81 | q31_t * pSrc) |
emilmont | 1:fdd22bb7aa52 | 82 | { |
emilmont | 1:fdd22bb7aa52 | 83 | |
mbed_official | 3:7a284390b0ce | 84 | if(S->ifftFlag == 1u) |
mbed_official | 3:7a284390b0ce | 85 | { |
mbed_official | 3:7a284390b0ce | 86 | arm_radix2_butterfly_inverse_q31(pSrc, S->fftLen, |
mbed_official | 3:7a284390b0ce | 87 | S->pTwiddle, S->twidCoefModifier); |
mbed_official | 3:7a284390b0ce | 88 | } |
mbed_official | 3:7a284390b0ce | 89 | else |
mbed_official | 3:7a284390b0ce | 90 | { |
mbed_official | 3:7a284390b0ce | 91 | arm_radix2_butterfly_q31(pSrc, S->fftLen, |
mbed_official | 3:7a284390b0ce | 92 | S->pTwiddle, S->twidCoefModifier); |
mbed_official | 3:7a284390b0ce | 93 | } |
emilmont | 1:fdd22bb7aa52 | 94 | |
mbed_official | 3:7a284390b0ce | 95 | arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable); |
mbed_official | 3:7a284390b0ce | 96 | } |
emilmont | 1:fdd22bb7aa52 | 97 | |
mbed_official | 3:7a284390b0ce | 98 | /** |
mbed_official | 3:7a284390b0ce | 99 | * @} end of ComplexFFT group |
mbed_official | 3:7a284390b0ce | 100 | */ |
emilmont | 1:fdd22bb7aa52 | 101 | |
mbed_official | 3:7a284390b0ce | 102 | void arm_radix2_butterfly_q31( |
mbed_official | 3:7a284390b0ce | 103 | q31_t * pSrc, |
mbed_official | 3:7a284390b0ce | 104 | uint32_t fftLen, |
mbed_official | 3:7a284390b0ce | 105 | q31_t * pCoef, |
mbed_official | 3:7a284390b0ce | 106 | uint16_t twidCoefModifier) |
mbed_official | 3:7a284390b0ce | 107 | { |
emilmont | 1:fdd22bb7aa52 | 108 | |
mbed_official | 3:7a284390b0ce | 109 | unsigned i, j, k, l, m; |
mbed_official | 3:7a284390b0ce | 110 | unsigned n1, n2, ia; |
mbed_official | 3:7a284390b0ce | 111 | q31_t xt, yt, cosVal, sinVal; |
mbed_official | 3:7a284390b0ce | 112 | q31_t p0, p1; |
mbed_official | 3:7a284390b0ce | 113 | |
mbed_official | 3:7a284390b0ce | 114 | //N = fftLen; |
mbed_official | 3:7a284390b0ce | 115 | n2 = fftLen; |
emilmont | 1:fdd22bb7aa52 | 116 | |
mbed_official | 3:7a284390b0ce | 117 | n1 = n2; |
mbed_official | 3:7a284390b0ce | 118 | n2 = n2 >> 1; |
mbed_official | 3:7a284390b0ce | 119 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 120 | |
mbed_official | 3:7a284390b0ce | 121 | // loop for groups |
mbed_official | 3:7a284390b0ce | 122 | for (i = 0; i < n2; i++) |
mbed_official | 3:7a284390b0ce | 123 | { |
emilmont | 1:fdd22bb7aa52 | 124 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 125 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 126 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 127 | |
mbed_official | 3:7a284390b0ce | 128 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 129 | xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u); |
mbed_official | 3:7a284390b0ce | 130 | pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u; |
mbed_official | 3:7a284390b0ce | 131 | |
mbed_official | 3:7a284390b0ce | 132 | yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u); |
mbed_official | 3:7a284390b0ce | 133 | pSrc[2 * i + 1] = |
mbed_official | 3:7a284390b0ce | 134 | ((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 135 | |
mbed_official | 3:7a284390b0ce | 136 | mult_32x32_keep32_R(p0, xt, cosVal); |
mbed_official | 3:7a284390b0ce | 137 | mult_32x32_keep32_R(p1, yt, cosVal); |
mbed_official | 3:7a284390b0ce | 138 | multAcc_32x32_keep32_R(p0, yt, sinVal); |
mbed_official | 3:7a284390b0ce | 139 | multSub_32x32_keep32_R(p1, xt, sinVal); |
mbed_official | 3:7a284390b0ce | 140 | |
mbed_official | 3:7a284390b0ce | 141 | pSrc[2u * l] = p0; |
mbed_official | 3:7a284390b0ce | 142 | pSrc[2u * l + 1u] = p1; |
emilmont | 1:fdd22bb7aa52 | 143 | |
mbed_official | 3:7a284390b0ce | 144 | } // groups loop end |
mbed_official | 3:7a284390b0ce | 145 | |
mbed_official | 3:7a284390b0ce | 146 | twidCoefModifier <<= 1u; |
emilmont | 1:fdd22bb7aa52 | 147 | |
mbed_official | 3:7a284390b0ce | 148 | // loop for stage |
mbed_official | 3:7a284390b0ce | 149 | for (k = fftLen / 2; k > 2; k = k >> 1) |
mbed_official | 3:7a284390b0ce | 150 | { |
mbed_official | 3:7a284390b0ce | 151 | n1 = n2; |
mbed_official | 3:7a284390b0ce | 152 | n2 = n2 >> 1; |
mbed_official | 3:7a284390b0ce | 153 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 154 | |
mbed_official | 3:7a284390b0ce | 155 | // loop for groups |
mbed_official | 3:7a284390b0ce | 156 | for (j = 0; j < n2; j++) |
mbed_official | 3:7a284390b0ce | 157 | { |
mbed_official | 3:7a284390b0ce | 158 | cosVal = pCoef[ia * 2]; |
mbed_official | 3:7a284390b0ce | 159 | sinVal = pCoef[(ia * 2) + 1]; |
mbed_official | 3:7a284390b0ce | 160 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 161 | |
mbed_official | 3:7a284390b0ce | 162 | // loop for butterfly |
mbed_official | 3:7a284390b0ce | 163 | i = j; |
mbed_official | 3:7a284390b0ce | 164 | m = fftLen / n1; |
mbed_official | 3:7a284390b0ce | 165 | do |
mbed_official | 3:7a284390b0ce | 166 | { |
mbed_official | 3:7a284390b0ce | 167 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 168 | xt = pSrc[2 * i] - pSrc[2 * l]; |
mbed_official | 3:7a284390b0ce | 169 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u; |
mbed_official | 3:7a284390b0ce | 170 | |
mbed_official | 3:7a284390b0ce | 171 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
mbed_official | 3:7a284390b0ce | 172 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 173 | |
mbed_official | 3:7a284390b0ce | 174 | mult_32x32_keep32_R(p0, xt, cosVal); |
mbed_official | 3:7a284390b0ce | 175 | mult_32x32_keep32_R(p1, yt, cosVal); |
mbed_official | 3:7a284390b0ce | 176 | multAcc_32x32_keep32_R(p0, yt, sinVal); |
mbed_official | 3:7a284390b0ce | 177 | multSub_32x32_keep32_R(p1, xt, sinVal); |
mbed_official | 3:7a284390b0ce | 178 | |
mbed_official | 3:7a284390b0ce | 179 | pSrc[2u * l] = p0; |
mbed_official | 3:7a284390b0ce | 180 | pSrc[2u * l + 1u] = p1; |
mbed_official | 3:7a284390b0ce | 181 | i += n1; |
mbed_official | 3:7a284390b0ce | 182 | m--; |
mbed_official | 3:7a284390b0ce | 183 | } while( m > 0); // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 184 | |
mbed_official | 3:7a284390b0ce | 185 | } // groups loop end |
mbed_official | 3:7a284390b0ce | 186 | |
mbed_official | 3:7a284390b0ce | 187 | twidCoefModifier <<= 1u; |
mbed_official | 3:7a284390b0ce | 188 | } // stages loop end |
emilmont | 1:fdd22bb7aa52 | 189 | |
mbed_official | 3:7a284390b0ce | 190 | n1 = n2; |
mbed_official | 3:7a284390b0ce | 191 | n2 = n2 >> 1; |
mbed_official | 3:7a284390b0ce | 192 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 193 | |
mbed_official | 3:7a284390b0ce | 194 | cosVal = pCoef[ia * 2]; |
mbed_official | 3:7a284390b0ce | 195 | sinVal = pCoef[(ia * 2) + 1]; |
mbed_official | 3:7a284390b0ce | 196 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 197 | |
mbed_official | 3:7a284390b0ce | 198 | // loop for butterfly |
mbed_official | 3:7a284390b0ce | 199 | for (i = 0; i < fftLen; i += n1) |
mbed_official | 3:7a284390b0ce | 200 | { |
mbed_official | 3:7a284390b0ce | 201 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 202 | xt = pSrc[2 * i] - pSrc[2 * l]; |
mbed_official | 3:7a284390b0ce | 203 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 204 | |
mbed_official | 3:7a284390b0ce | 205 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
mbed_official | 3:7a284390b0ce | 206 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 207 | |
mbed_official | 3:7a284390b0ce | 208 | pSrc[2u * l] = xt; |
mbed_official | 3:7a284390b0ce | 209 | |
mbed_official | 3:7a284390b0ce | 210 | pSrc[2u * l + 1u] = yt; |
emilmont | 1:fdd22bb7aa52 | 211 | |
mbed_official | 3:7a284390b0ce | 212 | i += n1; |
mbed_official | 3:7a284390b0ce | 213 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 214 | |
mbed_official | 3:7a284390b0ce | 215 | xt = pSrc[2 * i] - pSrc[2 * l]; |
mbed_official | 3:7a284390b0ce | 216 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 217 | |
mbed_official | 3:7a284390b0ce | 218 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
mbed_official | 3:7a284390b0ce | 219 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 220 | |
mbed_official | 3:7a284390b0ce | 221 | pSrc[2u * l] = xt; |
emilmont | 1:fdd22bb7aa52 | 222 | |
mbed_official | 3:7a284390b0ce | 223 | pSrc[2u * l + 1u] = yt; |
mbed_official | 3:7a284390b0ce | 224 | |
mbed_official | 3:7a284390b0ce | 225 | } // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 226 | |
emilmont | 1:fdd22bb7aa52 | 227 | } |
emilmont | 1:fdd22bb7aa52 | 228 | |
emilmont | 1:fdd22bb7aa52 | 229 | |
emilmont | 1:fdd22bb7aa52 | 230 | void arm_radix2_butterfly_inverse_q31( |
mbed_official | 3:7a284390b0ce | 231 | q31_t * pSrc, |
mbed_official | 3:7a284390b0ce | 232 | uint32_t fftLen, |
mbed_official | 3:7a284390b0ce | 233 | q31_t * pCoef, |
mbed_official | 3:7a284390b0ce | 234 | uint16_t twidCoefModifier) |
emilmont | 1:fdd22bb7aa52 | 235 | { |
emilmont | 1:fdd22bb7aa52 | 236 | |
mbed_official | 3:7a284390b0ce | 237 | unsigned i, j, k, l; |
mbed_official | 3:7a284390b0ce | 238 | unsigned n1, n2, ia; |
mbed_official | 3:7a284390b0ce | 239 | q31_t xt, yt, cosVal, sinVal; |
mbed_official | 3:7a284390b0ce | 240 | q31_t p0, p1; |
emilmont | 1:fdd22bb7aa52 | 241 | |
mbed_official | 3:7a284390b0ce | 242 | //N = fftLen; |
mbed_official | 3:7a284390b0ce | 243 | n2 = fftLen; |
emilmont | 1:fdd22bb7aa52 | 244 | |
mbed_official | 3:7a284390b0ce | 245 | n1 = n2; |
mbed_official | 3:7a284390b0ce | 246 | n2 = n2 >> 1; |
mbed_official | 3:7a284390b0ce | 247 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 248 | |
mbed_official | 3:7a284390b0ce | 249 | // loop for groups |
mbed_official | 3:7a284390b0ce | 250 | for (i = 0; i < n2; i++) |
mbed_official | 3:7a284390b0ce | 251 | { |
emilmont | 1:fdd22bb7aa52 | 252 | cosVal = pCoef[ia * 2]; |
emilmont | 1:fdd22bb7aa52 | 253 | sinVal = pCoef[(ia * 2) + 1]; |
emilmont | 1:fdd22bb7aa52 | 254 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 255 | |
mbed_official | 3:7a284390b0ce | 256 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 257 | xt = (pSrc[2 * i] >> 2u) - (pSrc[2 * l] >> 2u); |
mbed_official | 3:7a284390b0ce | 258 | pSrc[2 * i] = ((pSrc[2 * i] >> 2u) + (pSrc[2 * l] >> 2u)) >> 1u; |
mbed_official | 3:7a284390b0ce | 259 | |
mbed_official | 3:7a284390b0ce | 260 | yt = (pSrc[2 * i + 1] >> 2u) - (pSrc[2 * l + 1] >> 2u); |
mbed_official | 3:7a284390b0ce | 261 | pSrc[2 * i + 1] = |
mbed_official | 3:7a284390b0ce | 262 | ((pSrc[2 * l + 1] >> 2u) + (pSrc[2 * i + 1] >> 2u)) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 263 | |
mbed_official | 3:7a284390b0ce | 264 | mult_32x32_keep32_R(p0, xt, cosVal); |
mbed_official | 3:7a284390b0ce | 265 | mult_32x32_keep32_R(p1, yt, cosVal); |
mbed_official | 3:7a284390b0ce | 266 | multSub_32x32_keep32_R(p0, yt, sinVal); |
mbed_official | 3:7a284390b0ce | 267 | multAcc_32x32_keep32_R(p1, xt, sinVal); |
mbed_official | 3:7a284390b0ce | 268 | |
mbed_official | 3:7a284390b0ce | 269 | pSrc[2u * l] = p0; |
mbed_official | 3:7a284390b0ce | 270 | pSrc[2u * l + 1u] = p1; |
mbed_official | 3:7a284390b0ce | 271 | } // groups loop end |
emilmont | 1:fdd22bb7aa52 | 272 | |
mbed_official | 3:7a284390b0ce | 273 | twidCoefModifier = twidCoefModifier << 1u; |
emilmont | 1:fdd22bb7aa52 | 274 | |
mbed_official | 3:7a284390b0ce | 275 | // loop for stage |
mbed_official | 3:7a284390b0ce | 276 | for (k = fftLen / 2; k > 2; k = k >> 1) |
mbed_official | 3:7a284390b0ce | 277 | { |
mbed_official | 3:7a284390b0ce | 278 | n1 = n2; |
mbed_official | 3:7a284390b0ce | 279 | n2 = n2 >> 1; |
mbed_official | 3:7a284390b0ce | 280 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 281 | |
mbed_official | 3:7a284390b0ce | 282 | // loop for groups |
mbed_official | 3:7a284390b0ce | 283 | for (j = 0; j < n2; j++) |
mbed_official | 3:7a284390b0ce | 284 | { |
mbed_official | 3:7a284390b0ce | 285 | cosVal = pCoef[ia * 2]; |
mbed_official | 3:7a284390b0ce | 286 | sinVal = pCoef[(ia * 2) + 1]; |
mbed_official | 3:7a284390b0ce | 287 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 288 | |
mbed_official | 3:7a284390b0ce | 289 | // loop for butterfly |
mbed_official | 3:7a284390b0ce | 290 | for (i = j; i < fftLen; i += n1) |
mbed_official | 3:7a284390b0ce | 291 | { |
mbed_official | 3:7a284390b0ce | 292 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 293 | xt = pSrc[2 * i] - pSrc[2 * l]; |
mbed_official | 3:7a284390b0ce | 294 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u; |
mbed_official | 3:7a284390b0ce | 295 | |
mbed_official | 3:7a284390b0ce | 296 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
mbed_official | 3:7a284390b0ce | 297 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u; |
emilmont | 1:fdd22bb7aa52 | 298 | |
mbed_official | 3:7a284390b0ce | 299 | mult_32x32_keep32_R(p0, xt, cosVal); |
mbed_official | 3:7a284390b0ce | 300 | mult_32x32_keep32_R(p1, yt, cosVal); |
mbed_official | 3:7a284390b0ce | 301 | multSub_32x32_keep32_R(p0, yt, sinVal); |
mbed_official | 3:7a284390b0ce | 302 | multAcc_32x32_keep32_R(p1, xt, sinVal); |
mbed_official | 3:7a284390b0ce | 303 | |
mbed_official | 3:7a284390b0ce | 304 | pSrc[2u * l] = p0; |
mbed_official | 3:7a284390b0ce | 305 | pSrc[2u * l + 1u] = p1; |
mbed_official | 3:7a284390b0ce | 306 | } // butterfly loop end |
mbed_official | 3:7a284390b0ce | 307 | |
mbed_official | 3:7a284390b0ce | 308 | } // groups loop end |
emilmont | 1:fdd22bb7aa52 | 309 | |
mbed_official | 3:7a284390b0ce | 310 | twidCoefModifier = twidCoefModifier << 1u; |
mbed_official | 3:7a284390b0ce | 311 | } // stages loop end |
emilmont | 1:fdd22bb7aa52 | 312 | |
mbed_official | 3:7a284390b0ce | 313 | n1 = n2; |
mbed_official | 3:7a284390b0ce | 314 | n2 = n2 >> 1; |
mbed_official | 3:7a284390b0ce | 315 | ia = 0; |
emilmont | 1:fdd22bb7aa52 | 316 | |
mbed_official | 3:7a284390b0ce | 317 | cosVal = pCoef[ia * 2]; |
mbed_official | 3:7a284390b0ce | 318 | sinVal = pCoef[(ia * 2) + 1]; |
mbed_official | 3:7a284390b0ce | 319 | ia = ia + twidCoefModifier; |
emilmont | 1:fdd22bb7aa52 | 320 | |
mbed_official | 3:7a284390b0ce | 321 | // loop for butterfly |
mbed_official | 3:7a284390b0ce | 322 | for (i = 0; i < fftLen; i += n1) |
mbed_official | 3:7a284390b0ce | 323 | { |
mbed_official | 3:7a284390b0ce | 324 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 325 | xt = pSrc[2 * i] - pSrc[2 * l]; |
mbed_official | 3:7a284390b0ce | 326 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 327 | |
mbed_official | 3:7a284390b0ce | 328 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
mbed_official | 3:7a284390b0ce | 329 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 330 | |
mbed_official | 3:7a284390b0ce | 331 | pSrc[2u * l] = xt; |
mbed_official | 3:7a284390b0ce | 332 | |
mbed_official | 3:7a284390b0ce | 333 | pSrc[2u * l + 1u] = yt; |
emilmont | 1:fdd22bb7aa52 | 334 | |
mbed_official | 3:7a284390b0ce | 335 | i += n1; |
mbed_official | 3:7a284390b0ce | 336 | l = i + n2; |
mbed_official | 3:7a284390b0ce | 337 | |
mbed_official | 3:7a284390b0ce | 338 | xt = pSrc[2 * i] - pSrc[2 * l]; |
mbed_official | 3:7a284390b0ce | 339 | pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
emilmont | 1:fdd22bb7aa52 | 340 | |
mbed_official | 3:7a284390b0ce | 341 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
mbed_official | 3:7a284390b0ce | 342 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
emilmont | 1:fdd22bb7aa52 | 343 | |
mbed_official | 3:7a284390b0ce | 344 | pSrc[2u * l] = xt; |
emilmont | 1:fdd22bb7aa52 | 345 | |
mbed_official | 3:7a284390b0ce | 346 | pSrc[2u * l + 1u] = yt; |
mbed_official | 3:7a284390b0ce | 347 | |
mbed_official | 3:7a284390b0ce | 348 | } // butterfly loop end |
emilmont | 1:fdd22bb7aa52 | 349 | |
emilmont | 1:fdd22bb7aa52 | 350 | } |