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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_GetCbVec.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/get_cd_vec.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/create_augmented_vec.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
/*----------------------------------------------------------------*
* Construct codebook vector for given index.
*---------------------------------------------------------------*/
bool WebRtcIlbcfix_GetCbVec(
int16_t *cbvec, /* (o) Constructed codebook vector */
int16_t *mem, /* (i) Codebook buffer */
size_t index, /* (i) Codebook index */
size_t lMem, /* (i) Length of codebook buffer */
size_t cbveclen /* (i) Codebook vector length */
){
size_t k, base_size;
size_t lag;
/* Stack based */
int16_t tempbuff2[SUBL+5];
/* Determine size of codebook sections */
base_size=lMem-cbveclen+1;
if (cbveclen==SUBL) {
base_size += cbveclen / 2;
}
/* No filter -> First codebook section */
if (index<lMem-cbveclen+1) {
/* first non-interpolated vectors */
k=index+cbveclen;
/* get vector */
WEBRTC_SPL_MEMCPY_W16(cbvec, mem+lMem-k, cbveclen);
} else if (index < base_size) {
/* Calculate lag */
k = (2 * (index - (lMem - cbveclen + 1))) + cbveclen;
lag = k / 2;
WebRtcIlbcfix_CreateAugmentedVec(lag, mem+lMem, cbvec);
}
/* Higher codebbok section based on filtering */
else {
size_t memIndTest;
/* first non-interpolated vectors */
if (index-base_size<lMem-cbveclen+1) {
/* Set up filter memory, stuff zeros outside memory buffer */
memIndTest = lMem-(index-base_size+cbveclen);
WebRtcSpl_MemSetW16(mem-CB_HALFFILTERLEN, 0, CB_HALFFILTERLEN);
WebRtcSpl_MemSetW16(mem+lMem, 0, CB_HALFFILTERLEN);
/* do filtering to get the codebook vector */
WebRtcSpl_FilterMAFastQ12(
&mem[memIndTest+4], cbvec, (int16_t*)WebRtcIlbcfix_kCbFiltersRev,
CB_FILTERLEN, cbveclen);
}
/* interpolated vectors */
else {
if (cbveclen < SUBL) {
// We're going to fill in cbveclen + 5 elements of tempbuff2 in
// WebRtcSpl_FilterMAFastQ12, less than the SUBL + 5 elements we'll be
// using in WebRtcIlbcfix_CreateAugmentedVec. This error is caused by
// bad values in `index` (which come from the encoded stream). Tell the
// caller that things went south, and that the decoder state is now
// corrupt (because it's half-way through an update that we can't
// complete).
return false;
}
/* Stuff zeros outside memory buffer */
memIndTest = lMem-cbveclen-CB_FILTERLEN;
WebRtcSpl_MemSetW16(mem+lMem, 0, CB_HALFFILTERLEN);
/* do filtering */
WebRtcSpl_FilterMAFastQ12(
&mem[memIndTest+7], tempbuff2, (int16_t*)WebRtcIlbcfix_kCbFiltersRev,
CB_FILTERLEN, cbveclen+5);
/* Calculate lag index */
lag = (cbveclen<<1)-20+index-base_size-lMem-1;
WebRtcIlbcfix_CreateAugmentedVec(lag, tempbuff2+SUBL+5, cbvec);
}
}
return true; // Success.
}