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/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
WebRtcIlbcfix_AbsQuant.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/abs_quant.h"
#include "modules/audio_coding/codecs/ilbc/abs_quant_loop.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
/*----------------------------------------------------------------*
* predictive noise shaping encoding of scaled start state
* (subrutine for WebRtcIlbcfix_StateSearch)
*---------------------------------------------------------------*/
void WebRtcIlbcfix_AbsQuant(
IlbcEncoder *iLBCenc_inst,
/* (i) Encoder instance */
iLBC_bits *iLBC_encbits, /* (i/o) Encoded bits (outputs idxForMax
and idxVec, uses state_first as
input) */
int16_t *in, /* (i) vector to encode */
int16_t *weightDenum /* (i) denominator of synthesis filter */
) {
int16_t *syntOut;
size_t quantLen[2];
/* Stack based */
int16_t syntOutBuf[LPC_FILTERORDER+STATE_SHORT_LEN_30MS];
int16_t in_weightedVec[STATE_SHORT_LEN_30MS+LPC_FILTERORDER];
int16_t *in_weighted = &in_weightedVec[LPC_FILTERORDER];
/* Initialize the buffers */
WebRtcSpl_MemSetW16(syntOutBuf, 0, LPC_FILTERORDER+STATE_SHORT_LEN_30MS);
syntOut = &syntOutBuf[LPC_FILTERORDER];
/* Start with zero state */
WebRtcSpl_MemSetW16(in_weightedVec, 0, LPC_FILTERORDER);
/* Perform the quantization loop in two sections of length quantLen[i],
where the perceptual weighting filter is updated at the subframe
border */
if (iLBC_encbits->state_first) {
quantLen[0]=SUBL;
quantLen[1]=iLBCenc_inst->state_short_len-SUBL;
} else {
quantLen[0]=iLBCenc_inst->state_short_len-SUBL;
quantLen[1]=SUBL;
}
/* Calculate the weighted residual, switch perceptual weighting
filter at the subframe border */
WebRtcSpl_FilterARFastQ12(
in, in_weighted,
weightDenum, LPC_FILTERORDER+1, quantLen[0]);
WebRtcSpl_FilterARFastQ12(
&in[quantLen[0]], &in_weighted[quantLen[0]],
&weightDenum[LPC_FILTERORDER+1], LPC_FILTERORDER+1, quantLen[1]);
WebRtcIlbcfix_AbsQuantLoop(
syntOut,
in_weighted,
weightDenum,
quantLen,
iLBC_encbits->idxVec);
}
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