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06c2aa9f7b
WebRTC internal code should always use include paths that start from the root of the project and that clearly identify the header file. This allows 'gn check' to actually keep dependencies under control because 'gn check' cannot enforce anything if the include path is not fully qualified (starting from the root of the project). Bug: webrtc:8815 Change-Id: I36f01784fa5f5b77eefc02db479b1f7f6ee1a8c3 Reviewed-on: https://webrtc-review.googlesource.com/46263 Reviewed-by: Karl Wiberg <kwiberg@webrtc.org> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21871}
94 lines
3.4 KiB
C
94 lines
3.4 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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iLBC Speech Coder ANSI-C Source Code
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WebRtcIlbcfix_SimpleLpcAnalysis.c
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******************************************************************/
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#include "modules/audio_coding/codecs/ilbc/defines.h"
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#include "modules/audio_coding/codecs/ilbc/window32_w32.h"
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#include "modules/audio_coding/codecs/ilbc/bw_expand.h"
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#include "modules/audio_coding/codecs/ilbc/poly_to_lsf.h"
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#include "modules/audio_coding/codecs/ilbc/constants.h"
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/*----------------------------------------------------------------*
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* lpc analysis (subrutine to LPCencode)
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*---------------------------------------------------------------*/
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void WebRtcIlbcfix_SimpleLpcAnalysis(
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int16_t *lsf, /* (o) lsf coefficients */
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int16_t *data, /* (i) new block of speech */
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IlbcEncoder *iLBCenc_inst
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/* (i/o) the encoder state structure */
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) {
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int k;
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int scale;
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size_t is;
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int16_t stability;
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/* Stack based */
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int16_t A[LPC_FILTERORDER + 1];
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int32_t R[LPC_FILTERORDER + 1];
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int16_t windowedData[BLOCKL_MAX];
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int16_t rc[LPC_FILTERORDER];
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is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
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WEBRTC_SPL_MEMCPY_W16(iLBCenc_inst->lpc_buffer+is,data,iLBCenc_inst->blockl);
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/* No lookahead, last window is asymmetric */
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for (k = 0; k < iLBCenc_inst->lpc_n; k++) {
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is = LPC_LOOKBACK;
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if (k < (iLBCenc_inst->lpc_n - 1)) {
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/* Hanning table WebRtcIlbcfix_kLpcWin[] is in Q15-domain so the output is right-shifted 15 */
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WebRtcSpl_ElementwiseVectorMult(windowedData, iLBCenc_inst->lpc_buffer, WebRtcIlbcfix_kLpcWin, BLOCKL_MAX, 15);
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} else {
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/* Hanning table WebRtcIlbcfix_kLpcAsymWin[] is in Q15-domain so the output is right-shifted 15 */
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WebRtcSpl_ElementwiseVectorMult(windowedData, iLBCenc_inst->lpc_buffer+is, WebRtcIlbcfix_kLpcAsymWin, BLOCKL_MAX, 15);
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}
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/* Compute autocorrelation */
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WebRtcSpl_AutoCorrelation(windowedData, BLOCKL_MAX, LPC_FILTERORDER, R, &scale);
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/* Window autocorrelation vector */
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WebRtcIlbcfix_Window32W32(R, R, WebRtcIlbcfix_kLpcLagWin, LPC_FILTERORDER + 1 );
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/* Calculate the A coefficients from the Autocorrelation using Levinson Durbin algorithm */
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stability=WebRtcSpl_LevinsonDurbin(R, A, rc, LPC_FILTERORDER);
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/*
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Set the filter to {1.0, 0.0, 0.0,...} if filter from Levinson Durbin algorithm is unstable
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This should basically never happen...
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*/
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if (stability!=1) {
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A[0]=4096;
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WebRtcSpl_MemSetW16(&A[1], 0, LPC_FILTERORDER);
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}
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/* Bandwidth expand the filter coefficients */
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WebRtcIlbcfix_BwExpand(A, A, (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, LPC_FILTERORDER+1);
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/* Convert from A to LSF representation */
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WebRtcIlbcfix_Poly2Lsf(lsf + k*LPC_FILTERORDER, A);
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}
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is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
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WEBRTC_SPL_MEMCPY_W16(iLBCenc_inst->lpc_buffer,
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iLBCenc_inst->lpc_buffer+LPC_LOOKBACK+BLOCKL_MAX-is, is);
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return;
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}
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