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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_SimpleInterpolateLsf.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/simple_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_enc.h"
/*----------------------------------------------------------------*
* lsf interpolator (subrutine to LPCencode)
*---------------------------------------------------------------*/
void WebRtcIlbcfix_SimpleInterpolateLsf(
int16_t *syntdenum, /* (o) the synthesis filter denominator
resulting from the quantized
interpolated lsf Q12 */
int16_t *weightdenum, /* (o) the weighting filter denominator
resulting from the unquantized
interpolated lsf Q12 */
int16_t *lsf, /* (i) the unquantized lsf coefficients Q13 */
int16_t *lsfdeq, /* (i) the dequantized lsf coefficients Q13 */
int16_t *lsfold, /* (i) the unquantized lsf coefficients of
the previous signal frame Q13 */
int16_t *lsfdeqold, /* (i) the dequantized lsf coefficients of the
previous signal frame Q13 */
int16_t length, /* (i) should equate FILTERORDER */
IlbcEncoder *iLBCenc_inst
/* (i/o) the encoder state structure */
) {
size_t i;
int pos, lp_length;
int16_t *lsf2, *lsfdeq2;
/* Stack based */
int16_t lp[LPC_FILTERORDER + 1];
lsf2 = lsf + length;
lsfdeq2 = lsfdeq + length;
lp_length = length + 1;
if (iLBCenc_inst->mode==30) {
/* subframe 1: Interpolation between old and first set of
lsf coefficients */
/* Calculate Analysis/Syntehsis filter from quantized LSF */
WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
WebRtcIlbcfix_kLsfWeight30ms[0],
length);
WEBRTC_SPL_MEMCPY_W16(syntdenum, lp, lp_length);
/* Calculate Weighting filter from quantized LSF */
WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
WebRtcIlbcfix_kLsfWeight30ms[0],
length);
WebRtcIlbcfix_BwExpand(weightdenum, lp,
(int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
(int16_t)lp_length);
/* subframe 2 to 6: Interpolation between first and second
set of lsf coefficients */
pos = lp_length;
for (i = 1; i < iLBCenc_inst->nsub; i++) {
/* Calculate Analysis/Syntehsis filter from quantized LSF */
WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeq, lsfdeq2,
WebRtcIlbcfix_kLsfWeight30ms[i],
length);
WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
/* Calculate Weighting filter from quantized LSF */
WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsf, lsf2,
WebRtcIlbcfix_kLsfWeight30ms[i],
length);
WebRtcIlbcfix_BwExpand(weightdenum + pos, lp,
(int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
(int16_t)lp_length);
pos += lp_length;
}
/* update memory */
WEBRTC_SPL_MEMCPY_W16(lsfold, lsf2, length);
WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq2, length);
} else { /* iLBCenc_inst->mode==20 */
pos = 0;
for (i = 0; i < iLBCenc_inst->nsub; i++) {
/* Calculate Analysis/Syntehsis filter from quantized LSF */
WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfdeqold, lsfdeq,
WebRtcIlbcfix_kLsfWeight20ms[i],
length);
WEBRTC_SPL_MEMCPY_W16(syntdenum + pos, lp, lp_length);
/* Calculate Weighting filter from quantized LSF */
WebRtcIlbcfix_LsfInterpolate2PloyEnc(lp, lsfold, lsf,
WebRtcIlbcfix_kLsfWeight20ms[i],
length);
WebRtcIlbcfix_BwExpand(weightdenum+pos, lp,
(int16_t*)WebRtcIlbcfix_kLpcChirpWeightDenum,
(int16_t)lp_length);
pos += lp_length;
}
/* update memory */
WEBRTC_SPL_MEMCPY_W16(lsfold, lsf, length);
WEBRTC_SPL_MEMCPY_W16(lsfdeqold, lsfdeq, length);
}
return;
}
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