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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_LpcEncode.c
******************************************************************/
#include "defines.h"
#include "simple_lpc_analysis.h"
#include "simple_interpolate_lsf.h"
#include "simple_lsf_quant.h"
#include "lsf_check.h"
#include "constants.h"
/*----------------------------------------------------------------*
* lpc encoder
*---------------------------------------------------------------*/
void WebRtcIlbcfix_LpcEncode(
int16_t *syntdenum, /* (i/o) synthesis filter coefficients
before/after encoding */
int16_t *weightdenum, /* (i/o) weighting denumerator coefficients
before/after encoding */
int16_t *lsf_index, /* (o) lsf quantization index */
int16_t *data, /* (i) Speech to do LPC analysis on */
IlbcEncoder *iLBCenc_inst
/* (i/o) the encoder state structure */
) {
/* Stack based */
int16_t lsf[LPC_FILTERORDER * LPC_N_MAX];
int16_t lsfdeq[LPC_FILTERORDER * LPC_N_MAX];
/* Calculate LSF's from the input speech */
WebRtcIlbcfix_SimpleLpcAnalysis(lsf, data, iLBCenc_inst);
/* Quantize the LSF's */
WebRtcIlbcfix_SimpleLsfQ(lsfdeq, lsf_index, lsf, iLBCenc_inst->lpc_n);
/* Stableize the LSF's if needed */
WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCenc_inst->lpc_n);
/* Calculate the synthesis and weighting filter coefficients from
the optimal LSF and the dequantized LSF */
WebRtcIlbcfix_SimpleInterpolateLsf(syntdenum, weightdenum,
lsf, lsfdeq, iLBCenc_inst->lsfold,
iLBCenc_inst->lsfdeqold, LPC_FILTERORDER, iLBCenc_inst);
return;
}
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