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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_DecoderInterpolateLsp.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/decoder_interpolate_lsf.h"
#include "modules/audio_coding/codecs/ilbc/bw_expand.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
#include "modules/audio_coding/codecs/ilbc/lsf_interpolate_to_poly_dec.h"
/*----------------------------------------------------------------*
* obtain synthesis and weighting filters form lsf coefficients
*---------------------------------------------------------------*/
void WebRtcIlbcfix_DecoderInterpolateLsp(
int16_t *syntdenum, /* (o) synthesis filter coefficients */
int16_t *weightdenum, /* (o) weighting denumerator
coefficients */
int16_t *lsfdeq, /* (i) dequantized lsf coefficients */
int16_t length, /* (i) length of lsf coefficient vector */
IlbcDecoder *iLBCdec_inst
/* (i) the decoder state structure */
){
size_t i;
int pos, lp_length;
int16_t lp[LPC_FILTERORDER + 1], *lsfdeq2;
lsfdeq2 = lsfdeq + length;
lp_length = length + 1;
if (iLBCdec_inst->mode==30) {
/* subframe 1: Interpolation between old and first LSF */
WebRtcIlbcfix_LspInterpolate2PolyDec(lp, (*iLBCdec_inst).lsfdeqold, lsfdeq,
WebRtcIlbcfix_kLsfWeight30ms[0], length);
WEBRTC_SPL_MEMCPY_W16(syntdenum,lp,lp_length);
WebRtcIlbcfix_BwExpand(weightdenum, lp, (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)lp_length);
/* subframes 2 to 6: interpolation between first and last LSF */
pos = lp_length;
for (i = 1; i < 6; i++) {
WebRtcIlbcfix_LspInterpolate2PolyDec(lp, lsfdeq, lsfdeq2,
WebRtcIlbcfix_kLsfWeight30ms[i], length);
WEBRTC_SPL_MEMCPY_W16(syntdenum + pos,lp,lp_length);
WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
(int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)lp_length);
pos += lp_length;
}
} else { /* iLBCdec_inst->mode=20 */
/* subframes 1 to 4: interpolation between old and new LSF */
pos = 0;
for (i = 0; i < iLBCdec_inst->nsub; i++) {
WebRtcIlbcfix_LspInterpolate2PolyDec(lp, iLBCdec_inst->lsfdeqold, lsfdeq,
WebRtcIlbcfix_kLsfWeight20ms[i], length);
WEBRTC_SPL_MEMCPY_W16(syntdenum+pos,lp,lp_length);
WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
(int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, (int16_t)lp_length);
pos += lp_length;
}
}
/* update memory */
if (iLBCdec_inst->mode==30) {
WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq2, length);
} else {
WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->lsfdeqold, lsfdeq, length);
}
}
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