| /* |
| * 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( |
| WebRtc_Word16 *syntdenum, /* (i/o) synthesis filter coefficients |
| before/after encoding */ |
| WebRtc_Word16 *weightdenum, /* (i/o) weighting denumerator coefficients |
| before/after encoding */ |
| WebRtc_Word16 *lsf_index, /* (o) lsf quantization index */ |
| WebRtc_Word16 *data, /* (i) Speech to do LPC analysis on */ |
| iLBC_Enc_Inst_t *iLBCenc_inst |
| /* (i/o) the encoder state structure */ |
| ) { |
| /* Stack based */ |
| WebRtc_Word16 lsf[LPC_FILTERORDER * LPC_N_MAX]; |
| WebRtc_Word16 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; |
| } |