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61 lines
2.2 KiB
C
61 lines
2.2 KiB
C
/*
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* Copyright (c) 2011 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_LpcEncode.c
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******************************************************************/
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#include "defines.h"
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#include "simple_lpc_analysis.h"
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#include "simple_interpolate_lsf.h"
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#include "simple_lsf_quant.h"
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#include "lsf_check.h"
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#include "constants.h"
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/*----------------------------------------------------------------*
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* lpc encoder
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*---------------------------------------------------------------*/
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void WebRtcIlbcfix_LpcEncode(
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int16_t *syntdenum, /* (i/o) synthesis filter coefficients
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before/after encoding */
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int16_t *weightdenum, /* (i/o) weighting denumerator coefficients
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before/after encoding */
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int16_t *lsf_index, /* (o) lsf quantization index */
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int16_t *data, /* (i) Speech to do LPC analysis on */
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iLBC_Enc_Inst_t *iLBCenc_inst
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/* (i/o) the encoder state structure */
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) {
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/* Stack based */
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int16_t lsf[LPC_FILTERORDER * LPC_N_MAX];
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int16_t lsfdeq[LPC_FILTERORDER * LPC_N_MAX];
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/* Calculate LSF's from the input speech */
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WebRtcIlbcfix_SimpleLpcAnalysis(lsf, data, iLBCenc_inst);
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/* Quantize the LSF's */
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WebRtcIlbcfix_SimpleLsfQ(lsfdeq, lsf_index, lsf, iLBCenc_inst->lpc_n);
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/* Stableize the LSF's if needed */
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WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCenc_inst->lpc_n);
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/* Calculate the synthesis and weighting filter coefficients from
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the optimal LSF and the dequantized LSF */
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WebRtcIlbcfix_SimpleInterpolateLsf(syntdenum, weightdenum,
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lsf, lsfdeq, iLBCenc_inst->lsfold,
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iLBCenc_inst->lsfdeqold, LPC_FILTERORDER, iLBCenc_inst);
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return;
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}
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