1a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin/* 2a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * 4a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * Use of this source code is governed by a BSD-style license 5a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * that can be found in the LICENSE file in the root of the source 6a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * tree. An additional intellectual property rights grant can be found 7a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * in the file PATENTS. All contributing project authors may 8a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * be found in the AUTHORS file in the root of the source tree. 9a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin */ 10a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 11a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin/* 12a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * fft.c 13a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * 14a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * Fast Fourier Transform 15a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin * 16a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin */ 17a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 18a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 19a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin#include "fft.h" 20a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 21a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkinconst WebRtc_Word16 kSortTabFft[240] = { 22a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 0, 60, 120, 180, 20, 80, 140, 200, 40, 100, 160, 220, 23a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 4, 64, 124, 184, 24, 84, 144, 204, 44, 104, 164, 224, 24a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 8, 68, 128, 188, 28, 88, 148, 208, 48, 108, 168, 228, 25a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 12, 72, 132, 192, 32, 92, 152, 212, 52, 112, 172, 232, 26a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 16, 76, 136, 196, 36, 96, 156, 216, 56, 116, 176, 236, 27a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 1, 61, 121, 181, 21, 81, 141, 201, 41, 101, 161, 221, 28a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 5, 65, 125, 185, 25, 85, 145, 205, 45, 105, 165, 225, 29a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 9, 69, 129, 189, 29, 89, 149, 209, 49, 109, 169, 229, 30a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 13, 73, 133, 193, 33, 93, 153, 213, 53, 113, 173, 233, 31a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 17, 77, 137, 197, 37, 97, 157, 217, 57, 117, 177, 237, 32a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 2, 62, 122, 182, 22, 82, 142, 202, 42, 102, 162, 222, 33a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 6, 66, 126, 186, 26, 86, 146, 206, 46, 106, 166, 226, 34a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 10, 70, 130, 190, 30, 90, 150, 210, 50, 110, 170, 230, 35a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 14, 74, 134, 194, 34, 94, 154, 214, 54, 114, 174, 234, 36a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 18, 78, 138, 198, 38, 98, 158, 218, 58, 118, 178, 238, 37a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 3, 63, 123, 183, 23, 83, 143, 203, 43, 103, 163, 223, 38a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 7, 67, 127, 187, 27, 87, 147, 207, 47, 107, 167, 227, 39a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 11, 71, 131, 191, 31, 91, 151, 211, 51, 111, 171, 231, 40a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 15, 75, 135, 195, 35, 95, 155, 215, 55, 115, 175, 235, 41a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 19, 79, 139, 199, 39, 99, 159, 219, 59, 119, 179, 239 42a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin}; 43a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 44a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin/* Cosine table in Q14 */ 45a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkinconst WebRtc_Word16 kCosTabFfftQ14[240] = { 46a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 16384, 16378, 16362, 16333, 16294, 16244, 16182, 16110, 16026, 15931, 15826, 15709, 47a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 15582, 15444, 15296, 15137, 14968, 14788, 14598, 14399, 14189, 13970, 13741, 13502, 48a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 13255, 12998, 12733, 12458, 12176, 11885, 11585, 11278, 10963, 10641, 10311, 9974, 49a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 9630, 9280, 8923, 8561, 8192, 7818, 7438, 7053, 6664, 6270, 5872, 5469, 50a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 5063, 4653, 4240, 3825, 3406, 2986, 2563, 2139, 1713, 1285, 857, 429, 51a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 0, -429, -857, -1285, -1713, -2139, -2563, -2986, -3406, -3825, -4240, -4653, 52a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -5063, -5469, -5872, -6270, -6664, -7053, -7438, -7818, -8192, -8561, -8923, -9280, 53a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -9630, -9974, -10311, -10641, -10963, -11278, -11585, -11885, -12176, -12458, -12733, -12998, 54a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -13255, -13502, -13741, -13970, -14189, -14399, -14598, -14788, -14968, -15137, -15296, -15444, 55a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -15582, -15709, -15826, -15931, -16026, -16110, -16182, -16244, -16294, -16333, -16362, -16378, 56a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -16384, -16378, -16362, -16333, -16294, -16244, -16182, -16110, -16026, -15931, -15826, -15709, 57a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -15582, -15444, -15296, -15137, -14968, -14788, -14598, -14399, -14189, -13970, -13741, -13502, 58a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -13255, -12998, -12733, -12458, -12176, -11885, -11585, -11278, -10963, -10641, -10311, -9974, 59a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -9630, -9280, -8923, -8561, -8192, -7818, -7438, -7053, -6664, -6270, -5872, -5469, 60a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin -5063, -4653, -4240, -3825, -3406, -2986, -2563, -2139, -1713, -1285, -857, -429, 61a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 0, 429, 857, 1285, 1713, 2139, 2563, 2986, 3406, 3825, 4240, 4653, 62a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 5063, 5469, 5872, 6270, 6664, 7053, 7438, 7818, 8192, 8561, 8923, 9280, 63a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 9630, 9974, 10311, 10641, 10963, 11278, 11585, 11885, 12176, 12458, 12733, 12998, 64a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 13255, 13502, 13741, 13970, 14189, 14399, 14598, 14788, 14968, 15137, 15296, 15444, 65a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 15582, 15709, 15826, 15931, 16026, 16110, 16182, 16244, 16294, 16333, 16362, 16378 66a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin}; 67a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 68a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 69a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 70a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin/* Uses 16x16 mul, without rounding, which is faster. Uses WEBRTC_SPL_MUL_16_16_RSFT */ 71a6451827d543eb00824bc95097e47d0aac51ae93Alexander GutkinWebRtc_Word16 WebRtcIsacfix_FftRadix16Fastest(WebRtc_Word16 RexQx[], WebRtc_Word16 ImxQx[], WebRtc_Word16 iSign) { 72a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 73a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 dd, ee, ff, gg, hh, ii; 74a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 k0, k1, k2, k3, k4, kk; 75a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 tmp116, tmp216; 76a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 77a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 ccc1Q14, ccc2Q14, ccc3Q14, sss1Q14, sss2Q14, sss3Q14; 78a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 sss60Q14, ccc72Q14, sss72Q14; 79a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 aaQx, ajQx, akQx, ajmQx, ajpQx, akmQx, akpQx; 80a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 bbQx, bjQx, bkQx, bjmQx, bjpQx, bkmQx, bkpQx; 81a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 82a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin WebRtc_Word16 ReDATAQx[240], ImDATAQx[240]; 83a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 84a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss60Q14 = kCosTabFfftQ14[20]; 85a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc72Q14 = kCosTabFfftQ14[48]; 86a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss72Q14 = kCosTabFfftQ14[12]; 87a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 88a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign < 0) { 89a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss72Q14 = -sss72Q14; 90a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss60Q14 = -sss60Q14; 91a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 92a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* Complexity is: 10 cycles */ 93a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 94a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* compute fourier transform */ 95a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 96a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // transform for factor of 4 97a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (kk=0; kk<60; kk++) { 98a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k0 = kk; 99a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k1 = k0 + 60; 100a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k2 = k1 + 60; 101a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k3 = k2 + 60; 102a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 103a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = RexQx[k0] + RexQx[k2]; 104a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx = RexQx[k0] - RexQx[k2]; 105a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajpQx = RexQx[k1] + RexQx[k3]; 106a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajmQx = RexQx[k1] - RexQx[k3]; 107a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = ImxQx[k0] + ImxQx[k2]; 108a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx = ImxQx[k0] - ImxQx[k2]; 109a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjpQx = ImxQx[k1] + ImxQx[k3]; 110a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjmQx = ImxQx[k1] - ImxQx[k3]; 111a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 112a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k0] = akpQx + ajpQx; 113a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k0] = bkpQx + bjpQx; 114a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajpQx = akpQx - ajpQx; 115a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjpQx = bkpQx - bjpQx; 116a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign < 0) { 117a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = akmQx + bjmQx; 118a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = bkmQx - ajmQx; 119a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx -= bjmQx; 120a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx += ajmQx; 121a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } else { 122a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = akmQx - bjmQx; 123a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = bkmQx + ajmQx; 124a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx += bjmQx; 125a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx -= ajmQx; 126a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 127a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 128a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc1Q14 = kCosTabFfftQ14[kk]; 129a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc2Q14 = kCosTabFfftQ14[WEBRTC_SPL_MUL_16_16(2, kk)]; 130a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc3Q14 = kCosTabFfftQ14[WEBRTC_SPL_MUL_16_16(3, kk)]; 131a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss1Q14 = kCosTabFfftQ14[kk+60]; 132a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = kCosTabFfftQ14[WEBRTC_SPL_MUL_16_16(2, kk)+60]; 133a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss3Q14 = kCosTabFfftQ14[WEBRTC_SPL_MUL_16_16(3, kk)+60]; 134a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign==1) { 135a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss1Q14 = -sss1Q14; 136a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = -sss2Q14; 137a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss3Q14 = -sss3Q14; 138a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 139a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 140a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin //Do several multiplications like Q14*Q16>>14 = Q16 141a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // RexQ16[k1] = akpQ16 * ccc1Q14 - bkpQ16 * sss1Q14; 142a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // RexQ16[k2] = ajpQ16 * ccc2Q14 - bjpQ16 * sss2Q14; 143a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // RexQ16[k3] = akmQ16 * ccc3Q14 - bkmQ16 * sss3Q14; 144a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // ImxQ16[k1] = akpQ16 * sss1Q14 + bkpQ16 * ccc1Q14; 145a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // ImxQ16[k2] = ajpQ16 * sss2Q14 + bjpQ16 * ccc2Q14; 146a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // ImxQ16[k3] = akmQ16 * sss3Q14 + bkmQ16 * ccc3Q14; 147a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 148a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k1] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc1Q14, akpQx, 14) - 149a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss1Q14, bkpQx, 14); // 6 non-mul + 2 mul cycles, i.e. 8 cycles (6+2*7=20 cycles if 16x32mul) 150a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k2] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, ajpQx, 14) - 151a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, bjpQx, 14); 152a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k3] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc3Q14, akmQx, 14) - 153a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss3Q14, bkmQx, 14); 154a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k1] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss1Q14, akpQx, 14) + 155a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc1Q14, bkpQx, 14); 156a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k2] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, ajpQx, 14) + 157a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, bjpQx, 14); 158a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k3] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss3Q14, akmQx, 14) + 159a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc3Q14, bkmQx, 14); 160a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin //This mul segment needs 6*8 = 48 cycles for 16x16 muls, but 6*20 = 120 cycles for 16x32 muls 161a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 162a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 163a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 164a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* Complexity is: 51+48 = 99 cycles for 16x16 muls, but 51+120 = 171 cycles for 16x32 muls*/ 165a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 166a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // transform for factor of 3 167a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk=0; 168a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k1=20; 169a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k2=40; 170a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 171a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (hh=0; hh<4; hh++) { 172a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (ii=0; ii<20; ii++) { 173a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akQx = RexQx[kk]; 174a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkQx = ImxQx[kk]; 175a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajQx = RexQx[k1] + RexQx[k2]; 176a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjQx = ImxQx[k1] + ImxQx[k2]; 177a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[kk] = akQx + ajQx; 178a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[kk] = bkQx + bjQx; 179a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin tmp116 = WEBRTC_SPL_RSHIFT_W16(ajQx, 1); 180a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin tmp216 = WEBRTC_SPL_RSHIFT_W16(bjQx, 1); 181a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akQx = akQx - tmp116; 182a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkQx = bkQx - tmp216; 183a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin tmp116 = RexQx[k1] - RexQx[k2]; 184a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin tmp216 = ImxQx[k1] - ImxQx[k2]; 185a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 186a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss60Q14, tmp116, 14); // Q14*Qx>>14 = Qx 187a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss60Q14, tmp216, 14); // Q14*Qx>>14 = Qx 188a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k1] = akQx - bjQx; 189a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k2] = akQx + bjQx; 190a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k1] = bkQx + ajQx; 191a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k2] = bkQx - ajQx; 192a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 193a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk++; 194a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k1++; 195a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k2++; 196a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 197a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* Complexity : (31+6)*20 = 740 cycles for 16x16 muls, but (31+18)*20 = 980 cycles for 16x32 muls*/ 198a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk=kk+40; 199a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k1=k1+40; 200a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k2=k2+40; 201a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 202a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* Complexity : 4*(740+3) = 2972 cycles for 16x16 muls, but 4*(980+3) = 3932 cycles for 16x32 muls*/ 203a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 204a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* multiply by rotation factor for odd factor 3 or 5 (not for 4) 205a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin Same code (duplicated) for both ii=2 and ii=3 */ 206a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = 1; 207a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ee = 0; 208a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ff = 0; 209a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 210a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (gg=0; gg<19; gg++) { 211a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk += 20; 212a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ff = ff+4; 213a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (hh=0; hh<2; hh++) { 214a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ee = ff + (WebRtc_Word16)WEBRTC_SPL_MUL_16_16(hh, ff); 215a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin dd = ee + 60; 216a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc2Q14 = kCosTabFfftQ14[ee]; 217a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = kCosTabFfftQ14[dd]; 218a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign==1) { 219a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = -sss2Q14; 220a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 221a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (ii=0; ii<4; ii++) { 222a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akQx = RexQx[kk]; 223a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkQx = ImxQx[kk]; 224a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[kk] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, akQx, 14) - // Q14*Qx>>14 = Qx 225a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, bkQx, 14); 226a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[kk] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, akQx, 14) + // Q14*Qx>>14 = Qx 227a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, bkQx, 14); 228a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 229a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 230a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk += 60; 231a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 232a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = kk - 220; 233a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 234a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 2*(13+5+4*13+2) = 144 for 16x16 muls, but 2*(13+5+4*33+2) = 304 cycles for 16x32 muls 235a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = kk - 59; 236a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 237a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 19*144 = 2736 for 16x16 muls, but 19*304 = 5776 cycles for 16x32 muls 238a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 239a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // transform for factor of 5 240a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = 0; 241a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc2Q14 = kCosTabFfftQ14[96]; 242a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = kCosTabFfftQ14[84]; 243a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign==1) { 244a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = -sss2Q14; 245a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 246a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 247a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (hh=0; hh<4; hh++) { 248a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (ii=0; ii<12; ii++) { 249a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k1 = kk + 4; 250a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k2 = k1 + 4; 251a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k3 = k2 + 4; 252a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k4 = k3 + 4; 253a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 254a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = RexQx[k1] + RexQx[k4]; 255a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx = RexQx[k1] - RexQx[k4]; 256a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = ImxQx[k1] + ImxQx[k4]; 257a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx = ImxQx[k1] - ImxQx[k4]; 258a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajpQx = RexQx[k2] + RexQx[k3]; 259a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajmQx = RexQx[k2] - RexQx[k3]; 260a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjpQx = ImxQx[k2] + ImxQx[k3]; 261a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjmQx = ImxQx[k2] - ImxQx[k3]; 262a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin aaQx = RexQx[kk]; 263a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bbQx = ImxQx[kk]; 264a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[kk] = aaQx + akpQx + ajpQx; 265a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[kk] = bbQx + bkpQx + bjpQx; 266a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 267a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc72Q14, akpQx, 14) + 268a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, ajpQx, 14) + aaQx; 269a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc72Q14, bkpQx, 14) + 270a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, bjpQx, 14) + bbQx; 271a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss72Q14, akmQx, 14) + 272a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, ajmQx, 14); 273a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss72Q14, bkmQx, 14) + 274a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, bjmQx, 14); 275a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // 32+4*8=64 or 32+4*20=112 276a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 277a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k1] = akQx - bjQx; 278a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k4] = akQx + bjQx; 279a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k1] = bkQx + ajQx; 280a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k4] = bkQx - ajQx; 281a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 282a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, akpQx, 14) + 283a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc72Q14, ajpQx, 14) + aaQx; 284a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, bkpQx, 14) + 285a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc72Q14, bjpQx, 14) + bbQx; 286a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, akmQx, 14) - 287a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss72Q14, ajmQx, 14); 288a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjQx = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, bkmQx, 14) - 289a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss72Q14, bjmQx, 14); 290a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // 8+4*8=40 or 8+4*20=88 291a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 292a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k2] = akQx - bjQx; 293a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k3] = akQx + bjQx; 294a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k2] = bkQx + ajQx; 295a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k3] = bkQx - ajQx; 296a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 297a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = k4 + 4; 298a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 299a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 12*(64+40+10) = 1368 for 16x16 muls, but 12*(112+88+10) = 2520 cycles for 16x32 muls 300a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk -= 239; 301a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 302a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 4*1368 = 5472 for 16x16 muls, but 4*2520 = 10080 cycles for 16x32 muls 303a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 304a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* multiply by rotation factor for odd factor 3 or 5 (not for 4) 305a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin Same code (duplicated) for both ii=2 and ii=3 */ 306a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = 1; 307a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ee=0; 308a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 309a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (gg=0; gg<3; gg++) { 310a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk += 4; 311a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin dd = 12 + (WebRtc_Word16)WEBRTC_SPL_MUL_16_16(12, gg); 312a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ff = 0; 313a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (hh=0; hh<4; hh++) { 314a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ff = ff+dd; 315a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ee = ff+60; 316a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (ii=0; ii<12; ii++) { 317a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akQx = RexQx[kk]; 318a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkQx = ImxQx[kk]; 319a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 320a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ccc2Q14 = kCosTabFfftQ14[ff]; 321a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = kCosTabFfftQ14[ee]; 322a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 323a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign==1) { 324a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin sss2Q14 = -sss2Q14; 325a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 326a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 327a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[kk] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, akQx, 14) - 328a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, bkQx, 14); 329a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[kk] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(sss2Q14, akQx, 14) + 330a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(ccc2Q14, bkQx, 14); 331a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 332a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk += 20; 333a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 334a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = kk - 236; 335a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 12*(12+12) = 288 for 16x16 muls, but 12*(12+32) = 528 cycles for 16x32 muls 336a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 337a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin kk = kk - 19; 338a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 4*288+6 for 16x16 muls, but 4*528+6 cycles for 16x32 muls 339a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 340a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 3*4*288+6 = 3462 for 16x16 muls, but 3*4*528+6 = 6342 cycles for 16x32 muls 341a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 342a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 343a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // last transform for factor of 4 */ 344a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (kk=0; kk<240; kk=kk+4) { 345a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k1 = kk + 1; 346a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k2 = k1 + 1; 347a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin k3 = k2 + 1; 348a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 349a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = RexQx[kk] + RexQx[k2]; 350a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx = RexQx[kk] - RexQx[k2]; 351a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajpQx = RexQx[k1] + RexQx[k3]; 352a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajmQx = RexQx[k1] - RexQx[k3]; 353a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = ImxQx[kk] + ImxQx[k2]; 354a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx = ImxQx[kk] - ImxQx[k2]; 355a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjpQx = ImxQx[k1] + ImxQx[k3]; 356a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjmQx = ImxQx[k1] - ImxQx[k3]; 357a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[kk] = akpQx + ajpQx; 358a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[kk] = bkpQx + bjpQx; 359a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ajpQx = akpQx - ajpQx; 360a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bjpQx = bkpQx - bjpQx; 361a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin if (iSign < 0) { 362a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = akmQx + bjmQx; 363a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = bkmQx - ajmQx; 364a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx -= bjmQx; 365a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx += ajmQx; 366a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } else { 367a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akpQx = akmQx - bjmQx; 368a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkpQx = bkmQx + ajmQx; 369a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin akmQx += bjmQx; 370a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin bkmQx -= ajmQx; 371a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 372a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k1] = akpQx; 373a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k2] = ajpQx; 374a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[k3] = akmQx; 375a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k1] = bkpQx; 376a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k2] = bjpQx; 377a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[k3] = bkmQx; 378a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 379a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 60*45 = 2700 for 16x16 muls, but 60*45 = 2700 cycles for 16x32 muls 380a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 381a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin /* permute the results to normal order */ 382a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (ii=0; ii<240; ii++) { 383a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ReDATAQx[ii]=RexQx[ii]; 384a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImDATAQx[ii]=ImxQx[ii]; 385a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 386a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 240*2=480 cycles 387a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 388a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin for (ii=0; ii<240; ii++) { 389a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin RexQx[ii]=ReDATAQx[kSortTabFft[ii]]; 390a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin ImxQx[ii]=ImDATAQx[kSortTabFft[ii]]; 391a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin } 392a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 240*2*2=960 cycles 393a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 394a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Total complexity: 395a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // 16x16 16x32 396a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 10 10 397a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 99 171 398a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 2972 3932 399a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 2736 5776 400a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 5472 10080 401a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 3462 6342 402a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 2700 2700 403a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 480 480 404a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // Complexity: 960 960 405a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // ======================= 406a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // 18891 30451 407a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // 408a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // If this FFT is called 2 time each frame, i.e. 67 times per second, it will correspond to 409a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // a C54 complexity of 67*18891/1000000 = 1.27 MIPS with 16x16-muls, and 67*30451/1000000 = 410a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // = 2.04 MIPS with 16x32-muls. Note that this routine somtimes is called 6 times during the 411a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin // encoding of a frame, i.e. the max complexity would be 7/2*1.27 = 4.4 MIPS for the 16x16 mul case. 412a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 413a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin 414a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin return 0; 415a6451827d543eb00824bc95097e47d0aac51ae93Alexander Gutkin} 416