141 lines
5.0 KiB
C
141 lines
5.0 KiB
C
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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/*
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* This file contains the function WebRtcSpl_ComplexFFT().
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* The description header can be found in signal_processing_library.h
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*
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*/
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#include "signal_processing_library.h"
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#define CFFTSFT 14
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#define CFFTRND 1
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#define CFFTRND2 16384
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#if (defined ARM9E_GCC) || (defined ARM_WINM) || (defined ANDROID_AECOPT)
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extern "C" int FFT_4OFQ14(void *src, void *dest, int NC, int shift);
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// For detailed description of the fft functions, check the readme files in fft_ARM9E folder.
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int WebRtcSpl_ComplexFFT2(WebRtc_Word16 frfi[], WebRtc_Word16 frfiOut[], int stages, int mode)
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{
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return FFT_4OFQ14(frfi, frfiOut, 1 << stages, 0);
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}
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#endif
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int WebRtcSpl_ComplexFFT(WebRtc_Word16 frfi[], int stages, int mode)
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{
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int i, j, l, k, istep, n, m;
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WebRtc_Word16 wr, wi;
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WebRtc_Word32 tr32, ti32, qr32, qi32;
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/* The 1024-value is a constant given from the size of WebRtcSpl_kSinTable1024[],
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* and should not be changed depending on the input parameter 'stages'
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*/
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n = 1 << stages;
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if (n > 1024)
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return -1;
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l = 1;
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k = 10 - 1; /* Constant for given WebRtcSpl_kSinTable1024[]. Do not change
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depending on the input parameter 'stages' */
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if (mode == 0)
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{
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// mode==0: Low-complexity and Low-accuracy mode
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while (l < n)
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{
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istep = l << 1;
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for (m = 0; m < l; ++m)
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{
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j = m << k;
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/* The 256-value is a constant given as 1/4 of the size of
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* WebRtcSpl_kSinTable1024[], and should not be changed depending on the input
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* parameter 'stages'. It will result in 0 <= j < N_SINE_WAVE/2
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*/
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wr = WebRtcSpl_kSinTable1024[j + 256];
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wi = -WebRtcSpl_kSinTable1024[j];
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for (i = m; i < n; i += istep)
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{
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j = i + l;
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tr32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j])
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- WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j + 1])), 15);
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ti32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j + 1])
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+ WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j])), 15);
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qr32 = (WebRtc_Word32)frfi[2 * i];
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qi32 = (WebRtc_Word32)frfi[2 * i + 1];
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frfi[2 * j] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qr32 - tr32, 1);
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frfi[2 * j + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qi32 - ti32, 1);
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frfi[2 * i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qr32 + tr32, 1);
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frfi[2 * i + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(qi32 + ti32, 1);
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}
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}
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--k;
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l = istep;
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}
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} else
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{
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// mode==1: High-complexity and High-accuracy mode
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while (l < n)
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{
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istep = l << 1;
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for (m = 0; m < l; ++m)
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{
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j = m << k;
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/* The 256-value is a constant given as 1/4 of the size of
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* WebRtcSpl_kSinTable1024[], and should not be changed depending on the input
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* parameter 'stages'. It will result in 0 <= j < N_SINE_WAVE/2
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*/
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wr = WebRtcSpl_kSinTable1024[j + 256];
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wi = -WebRtcSpl_kSinTable1024[j];
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for (i = m; i < n; i += istep)
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{
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j = i + l;
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tr32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j])
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- WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j + 1]) + CFFTRND),
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15 - CFFTSFT);
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ti32 = WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL_16_16(wr, frfi[2 * j + 1])
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+ WEBRTC_SPL_MUL_16_16(wi, frfi[2 * j]) + CFFTRND), 15 - CFFTSFT);
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qr32 = ((WebRtc_Word32)frfi[2 * i]) << CFFTSFT;
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qi32 = ((WebRtc_Word32)frfi[2 * i + 1]) << CFFTSFT;
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frfi[2 * j] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
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(qr32 - tr32 + CFFTRND2), 1 + CFFTSFT);
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frfi[2 * j + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
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(qi32 - ti32 + CFFTRND2), 1 + CFFTSFT);
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frfi[2 * i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
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(qr32 + tr32 + CFFTRND2), 1 + CFFTSFT);
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frfi[2 * i + 1] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(
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(qi32 + ti32 + CFFTRND2), 1 + CFFTSFT);
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}
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}
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--k;
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l = istep;
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}
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}
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return 0;
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}
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