1 /* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 12 /* 13 * This file contains the function WebRtcSpl_ComplexFFT(). 14 * The description header can be found in signal_processing_library.h 15 * 16 */ 17 18 #include "signal_processing_library.h" 19 20 #define CFFTSFT 14 21 #define CFFTRND 1 22 #define CFFTRND2 16384 23 24 #if (defined ARM9E_GCC) || (defined ARM_WINM) || (defined ANDROID_AECOPT) 25 extern "C" int FFT_4OFQ14(void *src, void *dest, int NC, int shift); 26 27 // For detailed description of the fft functions, check the readme files in fft_ARM9E folder. 28 int WebRtcSpl_ComplexFFT2(WebRtc_Word16 frfi[], WebRtc_Word16 frfiOut[], int stages, int mode) 29 { 30 return FFT_4OFQ14(frfi, frfiOut, 1 << stages, 0); 31 } 32 #endif 33 34 int WebRtcSpl_ComplexFFT(WebRtc_Word16 frfi[], int stages, int mode) 35 { 36 int i, j, l, k, istep, n, m; 37 WebRtc_Word16 wr, wi; 38 WebRtc_Word32 tr32, ti32, qr32, qi32; 39 40 /* The 1024-value is a constant given from the size of WebRtcSpl_kSinTable1024[], 41 * and should not be changed depending on the input parameter 'stages' 42 */ 43 n = 1 << stages; 44 if (n > 1024) 45 return -1; 46 47 l = 1; 48 k = 10 - 1; /* Constant for given WebRtcSpl_kSinTable1024[]. Do not change 49 depending on the input parameter 'stages' */ 50 51 if (mode == 0) 52 { 53 // mode==0: Low-complexity and Low-accuracy mode 54 while (l < n) 55 { 56 istep = l << 1; 57 58 for (m = 0; m < l; ++m) 59 { 60 j = m << k; 61 62 /* The 256-value is a constant given as 1/4 of the size of 63 * WebRtcSpl_kSinTable1024[], and should not be changed depending on the input 64 * parameter 'stages'. It will result in 0 <= j < N_SINE_WAVE/2 65 */ 66 wr = WebRtcSpl_kSinTable1024[j + 256]; 67 wi = -WebRtcSpl_kSinTable1024[j]; 68 69 for (i = m; i < n; i += istep) 70 { 71 j = i + l; 72 73 tr32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j]) 74 - WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j + 1])), 15); 75 76 ti32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j + 1]) 77 + WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j])), 15); 78 79 qr32 = (WebRtc_Word32)frfi[2 * i]; 80 qi32 = (WebRtc_Word32)frfi[2 * i + 1]; 81 frfi[2 * j] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qr32 - tr32, 1); 82 frfi[2 * j + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qi32 - ti32, 1); 83 frfi[2 * i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qr32 + tr32, 1); 84 frfi[2 * i + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qi32 + ti32, 1); 85 } 86 } 87 88 --k; 89 l = istep; 90 91 } 92 93 } else 94 { 95 // mode==1: High-complexity and High-accuracy mode 96 while (l < n) 97 { 98 istep = l << 1; 99 100 for (m = 0; m < l; ++m) 101 { 102 j = m << k; 103 104 /* The 256-value is a constant given as 1/4 of the size of 105 * WebRtcSpl_kSinTable1024[], and should not be changed depending on the input 106 * parameter 'stages'. It will result in 0 <= j < N_SINE_WAVE/2 107 */ 108 wr = WebRtcSpl_kSinTable1024[j + 256]; 109 wi = -WebRtcSpl_kSinTable1024[j]; 110 111 for (i = m; i < n; i += istep) 112 { 113 j = i + l; 114 115 tr32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j]) 116 - WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j + 1]) + CFFTRND), 117 15 - CFFTSFT); 118 119 ti32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j + 1]) 120 + WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j]) + CFFTRND), 15 - CFFTSFT); 121 122 qr32 = ((WebRtc_Word32)frfi[2 * i]) << CFFTSFT; 123 qi32 = ((WebRtc_Word32)frfi[2 * i + 1]) << CFFTSFT; 124 frfi[2 * j] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32( 125 (qr32 - tr32 + CFFTRND2), 1 + CFFTSFT); 126 frfi[2 * j + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32( 127 (qi32 - ti32 + CFFTRND2), 1 + CFFTSFT); 128 frfi[2 * i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32( 129 (qr32 + tr32 + CFFTRND2), 1 + CFFTSFT); 130 frfi[2 * i + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32( 131 (qi32 + ti32 + CFFTRND2), 1 + CFFTSFT); 132 } 133 } 134 135 --k; 136 l = istep; 137 } 138 } 139 return 0; 140 } 141
