mirror of
https://github.com/mollyim/webrtc.git
synced 2025-05-13 22:00:47 +01:00
3111783aa1
Prior to this commit, most .c files in modules/audio_coding/codecs/ilbc don't include their corresponding headers, nor do they order #includes as per the Google Style Guide [1]. The former is especially harmful, since in C it can silently allow the function signature to diverge from its prototype, thus causing disaster at runtime. This CL fixes both issues. In effect, this allows the common_audio and modules/audio_coding:ilbc targets to be compiled with Clang's -Wmissing-prototypes, though this CL does not add that change. [1]: https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes Bug: webrtc:12314 Change-Id: I8299968ed3cc86ff35d9de045072b846298043af Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/198362 Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org> Commit-Queue: Timothy Gu <timothygu@chromium.org> Cr-Commit-Position: refs/heads/master@{#32896}
96 lines
3.4 KiB
C
96 lines
3.4 KiB
C
/*
|
|
* 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_SimpleLpcAnalysis.c
|
|
|
|
******************************************************************/
|
|
|
|
#include "modules/audio_coding/codecs/ilbc/simple_lpc_analysis.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/poly_to_lsf.h"
|
|
#include "modules/audio_coding/codecs/ilbc/window32_w32.h"
|
|
|
|
/*----------------------------------------------------------------*
|
|
* lpc analysis (subrutine to LPCencode)
|
|
*---------------------------------------------------------------*/
|
|
|
|
void WebRtcIlbcfix_SimpleLpcAnalysis(
|
|
int16_t *lsf, /* (o) lsf coefficients */
|
|
int16_t *data, /* (i) new block of speech */
|
|
IlbcEncoder *iLBCenc_inst
|
|
/* (i/o) the encoder state structure */
|
|
) {
|
|
int k;
|
|
int scale;
|
|
size_t is;
|
|
int16_t stability;
|
|
/* Stack based */
|
|
int16_t A[LPC_FILTERORDER + 1];
|
|
int32_t R[LPC_FILTERORDER + 1];
|
|
int16_t windowedData[BLOCKL_MAX];
|
|
int16_t rc[LPC_FILTERORDER];
|
|
|
|
is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
|
|
WEBRTC_SPL_MEMCPY_W16(iLBCenc_inst->lpc_buffer+is,data,iLBCenc_inst->blockl);
|
|
|
|
/* No lookahead, last window is asymmetric */
|
|
|
|
for (k = 0; k < iLBCenc_inst->lpc_n; k++) {
|
|
|
|
is = LPC_LOOKBACK;
|
|
|
|
if (k < (iLBCenc_inst->lpc_n - 1)) {
|
|
|
|
/* Hanning table WebRtcIlbcfix_kLpcWin[] is in Q15-domain so the output is right-shifted 15 */
|
|
WebRtcSpl_ElementwiseVectorMult(windowedData, iLBCenc_inst->lpc_buffer, WebRtcIlbcfix_kLpcWin, BLOCKL_MAX, 15);
|
|
} else {
|
|
|
|
/* Hanning table WebRtcIlbcfix_kLpcAsymWin[] is in Q15-domain so the output is right-shifted 15 */
|
|
WebRtcSpl_ElementwiseVectorMult(windowedData, iLBCenc_inst->lpc_buffer+is, WebRtcIlbcfix_kLpcAsymWin, BLOCKL_MAX, 15);
|
|
}
|
|
|
|
/* Compute autocorrelation */
|
|
WebRtcSpl_AutoCorrelation(windowedData, BLOCKL_MAX, LPC_FILTERORDER, R, &scale);
|
|
|
|
/* Window autocorrelation vector */
|
|
WebRtcIlbcfix_Window32W32(R, R, WebRtcIlbcfix_kLpcLagWin, LPC_FILTERORDER + 1 );
|
|
|
|
/* Calculate the A coefficients from the Autocorrelation using Levinson Durbin algorithm */
|
|
stability=WebRtcSpl_LevinsonDurbin(R, A, rc, LPC_FILTERORDER);
|
|
|
|
/*
|
|
Set the filter to {1.0, 0.0, 0.0,...} if filter from Levinson Durbin algorithm is unstable
|
|
This should basically never happen...
|
|
*/
|
|
if (stability!=1) {
|
|
A[0]=4096;
|
|
WebRtcSpl_MemSetW16(&A[1], 0, LPC_FILTERORDER);
|
|
}
|
|
|
|
/* Bandwidth expand the filter coefficients */
|
|
WebRtcIlbcfix_BwExpand(A, A, (int16_t*)WebRtcIlbcfix_kLpcChirpSyntDenum, LPC_FILTERORDER+1);
|
|
|
|
/* Convert from A to LSF representation */
|
|
WebRtcIlbcfix_Poly2Lsf(lsf + k*LPC_FILTERORDER, A);
|
|
}
|
|
|
|
is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
|
|
WEBRTC_SPL_MEMCPY_W16(iLBCenc_inst->lpc_buffer,
|
|
iLBCenc_inst->lpc_buffer+LPC_LOOKBACK+BLOCKL_MAX-is, is);
|
|
|
|
return;
|
|
}
|