261 lines
8.9 KiB
C
261 lines
8.9 KiB
C
/*
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* Copyright (c) 2012 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_Decode.c
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******************************************************************/
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// Defines WEBRTC_ARCH_BIG_ENDIAN, used below.
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#include "rtc_base/system/arch.h"
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#include "modules/audio_coding/codecs/ilbc/defines.h"
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#include "modules/audio_coding/codecs/ilbc/simple_lsf_dequant.h"
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#include "modules/audio_coding/codecs/ilbc/decoder_interpolate_lsf.h"
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#include "modules/audio_coding/codecs/ilbc/index_conv_dec.h"
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#include "modules/audio_coding/codecs/ilbc/do_plc.h"
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#include "modules/audio_coding/codecs/ilbc/constants.h"
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#include "modules/audio_coding/codecs/ilbc/enhancer_interface.h"
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#include "modules/audio_coding/codecs/ilbc/xcorr_coef.h"
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#include "modules/audio_coding/codecs/ilbc/lsf_check.h"
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#include "modules/audio_coding/codecs/ilbc/decode_residual.h"
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#include "modules/audio_coding/codecs/ilbc/unpack_bits.h"
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#include "modules/audio_coding/codecs/ilbc/hp_output.h"
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#include "modules/audio_coding/codecs/ilbc/init_decode.h"
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#ifndef WEBRTC_ARCH_BIG_ENDIAN
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#include "modules/audio_coding/codecs/ilbc/swap_bytes.h"
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#endif
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/*----------------------------------------------------------------*
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* main decoder function
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*---------------------------------------------------------------*/
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int WebRtcIlbcfix_DecodeImpl(
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int16_t *decblock, /* (o) decoded signal block */
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const uint16_t *bytes, /* (i) encoded signal bits */
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IlbcDecoder *iLBCdec_inst, /* (i/o) the decoder state
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structure */
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int16_t mode /* (i) 0: bad packet, PLC,
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1: normal */
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) {
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const int old_mode = iLBCdec_inst->mode;
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const int old_use_enhancer = iLBCdec_inst->use_enhancer;
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size_t i;
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int16_t order_plus_one;
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int16_t last_bit;
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int16_t *data;
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/* Stack based */
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int16_t decresidual[BLOCKL_MAX];
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int16_t PLCresidual[BLOCKL_MAX + LPC_FILTERORDER];
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int16_t syntdenum[NSUB_MAX*(LPC_FILTERORDER+1)];
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int16_t PLClpc[LPC_FILTERORDER + 1];
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#ifndef WEBRTC_ARCH_BIG_ENDIAN
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uint16_t swapped[NO_OF_WORDS_30MS];
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#endif
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iLBC_bits *iLBCbits_inst = (iLBC_bits*)PLCresidual;
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/* Reuse some buffers that are non overlapping in order to save stack memory */
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data = &PLCresidual[LPC_FILTERORDER];
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if (mode) { /* the data are good */
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/* decode data */
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/* Unpacketize bits into parameters */
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#ifndef WEBRTC_ARCH_BIG_ENDIAN
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WebRtcIlbcfix_SwapBytes(bytes, iLBCdec_inst->no_of_words, swapped);
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last_bit = WebRtcIlbcfix_UnpackBits(swapped, iLBCbits_inst, iLBCdec_inst->mode);
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#else
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last_bit = WebRtcIlbcfix_UnpackBits(bytes, iLBCbits_inst, iLBCdec_inst->mode);
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#endif
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/* Check for bit errors */
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if (iLBCbits_inst->startIdx<1)
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mode = 0;
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if ((iLBCdec_inst->mode==20) && (iLBCbits_inst->startIdx>3))
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mode = 0;
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if ((iLBCdec_inst->mode==30) && (iLBCbits_inst->startIdx>5))
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mode = 0;
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if (last_bit==1)
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mode = 0;
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if (mode) { /* No bit errors was detected, continue decoding */
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/* Stack based */
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int16_t lsfdeq[LPC_FILTERORDER*LPC_N_MAX];
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int16_t weightdenum[(LPC_FILTERORDER + 1)*NSUB_MAX];
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/* adjust index */
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WebRtcIlbcfix_IndexConvDec(iLBCbits_inst->cb_index);
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/* decode the lsf */
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WebRtcIlbcfix_SimpleLsfDeQ(lsfdeq, (int16_t*)(iLBCbits_inst->lsf), iLBCdec_inst->lpc_n);
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WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCdec_inst->lpc_n);
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WebRtcIlbcfix_DecoderInterpolateLsp(syntdenum, weightdenum,
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lsfdeq, LPC_FILTERORDER, iLBCdec_inst);
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/* Decode the residual using the cb and gain indexes */
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if (!WebRtcIlbcfix_DecodeResidual(iLBCdec_inst, iLBCbits_inst,
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decresidual, syntdenum))
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goto error;
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/* preparing the plc for a future loss! */
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WebRtcIlbcfix_DoThePlc(
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PLCresidual, PLClpc, 0, decresidual,
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syntdenum + (LPC_FILTERORDER + 1) * (iLBCdec_inst->nsub - 1),
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iLBCdec_inst->last_lag, iLBCdec_inst);
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/* Use the output from doThePLC */
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WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl);
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}
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}
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if (mode == 0) {
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/* the data is bad (either a PLC call
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* was made or a bit error was detected)
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*/
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/* packet loss conceal */
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WebRtcIlbcfix_DoThePlc(PLCresidual, PLClpc, 1, decresidual, syntdenum,
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iLBCdec_inst->last_lag, iLBCdec_inst);
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WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl);
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order_plus_one = LPC_FILTERORDER + 1;
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for (i = 0; i < iLBCdec_inst->nsub; i++) {
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WEBRTC_SPL_MEMCPY_W16(syntdenum+(i*order_plus_one),
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PLClpc, order_plus_one);
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}
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}
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if ((*iLBCdec_inst).use_enhancer == 1) { /* Enhancer activated */
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/* Update the filter and filter coefficients if there was a packet loss */
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if (iLBCdec_inst->prev_enh_pl==2) {
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for (i=0;i<iLBCdec_inst->nsub;i++) {
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WEBRTC_SPL_MEMCPY_W16(&(iLBCdec_inst->old_syntdenum[i*(LPC_FILTERORDER+1)]),
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syntdenum, (LPC_FILTERORDER+1));
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}
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}
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/* post filtering */
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(*iLBCdec_inst).last_lag =
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WebRtcIlbcfix_EnhancerInterface(data, decresidual, iLBCdec_inst);
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/* synthesis filtering */
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/* Set up the filter state */
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WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER);
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if (iLBCdec_inst->mode==20) {
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/* Enhancer has 40 samples delay */
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i=0;
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WebRtcSpl_FilterARFastQ12(
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data, data,
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iLBCdec_inst->old_syntdenum + (i+iLBCdec_inst->nsub-1)*(LPC_FILTERORDER+1),
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LPC_FILTERORDER+1, SUBL);
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for (i=1; i < iLBCdec_inst->nsub; i++) {
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WebRtcSpl_FilterARFastQ12(
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data+i*SUBL, data+i*SUBL,
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syntdenum+(i-1)*(LPC_FILTERORDER+1),
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LPC_FILTERORDER+1, SUBL);
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}
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} else if (iLBCdec_inst->mode==30) {
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/* Enhancer has 80 samples delay */
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for (i=0; i < 2; i++) {
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WebRtcSpl_FilterARFastQ12(
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data+i*SUBL, data+i*SUBL,
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iLBCdec_inst->old_syntdenum + (i+4)*(LPC_FILTERORDER+1),
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LPC_FILTERORDER+1, SUBL);
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}
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for (i=2; i < iLBCdec_inst->nsub; i++) {
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WebRtcSpl_FilterARFastQ12(
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data+i*SUBL, data+i*SUBL,
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syntdenum+(i-2)*(LPC_FILTERORDER+1),
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LPC_FILTERORDER+1, SUBL);
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}
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}
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/* Save the filter state */
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WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER);
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} else { /* Enhancer not activated */
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size_t lag;
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/* Find last lag (since the enhancer is not called to give this info) */
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lag = 20;
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if (iLBCdec_inst->mode==20) {
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lag = WebRtcIlbcfix_XcorrCoef(
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&decresidual[iLBCdec_inst->blockl-60],
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&decresidual[iLBCdec_inst->blockl-60-lag],
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60,
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80, lag, -1);
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} else {
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lag = WebRtcIlbcfix_XcorrCoef(
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&decresidual[iLBCdec_inst->blockl-ENH_BLOCKL],
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&decresidual[iLBCdec_inst->blockl-ENH_BLOCKL-lag],
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ENH_BLOCKL,
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100, lag, -1);
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}
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/* Store lag (it is needed if next packet is lost) */
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(*iLBCdec_inst).last_lag = lag;
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/* copy data and run synthesis filter */
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WEBRTC_SPL_MEMCPY_W16(data, decresidual, iLBCdec_inst->blockl);
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/* Set up the filter state */
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WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER);
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for (i=0; i < iLBCdec_inst->nsub; i++) {
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WebRtcSpl_FilterARFastQ12(
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data+i*SUBL, data+i*SUBL,
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syntdenum + i*(LPC_FILTERORDER+1),
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LPC_FILTERORDER+1, SUBL);
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}
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/* Save the filter state */
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WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER);
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}
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WEBRTC_SPL_MEMCPY_W16(decblock,data,iLBCdec_inst->blockl);
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/* High pass filter the signal (with upscaling a factor 2 and saturation) */
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WebRtcIlbcfix_HpOutput(decblock, (int16_t*)WebRtcIlbcfix_kHpOutCoefs,
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iLBCdec_inst->hpimemy, iLBCdec_inst->hpimemx,
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iLBCdec_inst->blockl);
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WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->old_syntdenum,
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syntdenum, iLBCdec_inst->nsub*(LPC_FILTERORDER+1));
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iLBCdec_inst->prev_enh_pl=0;
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if (mode==0) { /* PLC was used */
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iLBCdec_inst->prev_enh_pl=1;
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}
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return 0; // Success.
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error:
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// The decoder got sick from eating that data. Reset it and return.
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WebRtcIlbcfix_InitDecode(iLBCdec_inst, old_mode, old_use_enhancer);
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return -1; // Error
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}
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