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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_DecodeResidual.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/decode_residual.h"
#include <string.h>
#include "modules/audio_coding/codecs/ilbc/cb_construct.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
#include "modules/audio_coding/codecs/ilbc/do_plc.h"
#include "modules/audio_coding/codecs/ilbc/enhancer_interface.h"
#include "modules/audio_coding/codecs/ilbc/index_conv_dec.h"
#include "modules/audio_coding/codecs/ilbc/lsf_check.h"
#include "modules/audio_coding/codecs/ilbc/state_construct.h"
#include "modules/audio_coding/codecs/ilbc/xcorr_coef.h"
/*----------------------------------------------------------------*
* frame residual decoder function (subrutine to iLBC_decode)
*---------------------------------------------------------------*/
bool WebRtcIlbcfix_DecodeResidual(
IlbcDecoder *iLBCdec_inst,
/* (i/o) the decoder state structure */
iLBC_bits *iLBC_encbits, /* (i/o) Encoded bits, which are used
for the decoding */
int16_t *decresidual, /* (o) decoded residual frame */
int16_t *syntdenum /* (i) the decoded synthesis filter
coefficients */
) {
size_t meml_gotten, diff, start_pos;
size_t subcount, subframe;
int16_t *reverseDecresidual = iLBCdec_inst->enh_buf; /* Reversed decoded data, used for decoding backwards in time (reuse memory in state) */
int16_t *memVec = iLBCdec_inst->prevResidual; /* Memory for codebook and filter state (reuse memory in state) */
int16_t *mem = &memVec[CB_HALFFILTERLEN]; /* Memory for codebook */
diff = STATE_LEN - iLBCdec_inst->state_short_len;
if (iLBC_encbits->state_first == 1) {
start_pos = (iLBC_encbits->startIdx-1)*SUBL;
} else {
start_pos = (iLBC_encbits->startIdx-1)*SUBL + diff;
}
/* decode scalar part of start state */
WebRtcIlbcfix_StateConstruct(iLBC_encbits->idxForMax,
iLBC_encbits->idxVec, &syntdenum[(iLBC_encbits->startIdx-1)*(LPC_FILTERORDER+1)],
&decresidual[start_pos], iLBCdec_inst->state_short_len
);
if (iLBC_encbits->state_first) { /* put adaptive part in the end */
/* setup memory */
WebRtcSpl_MemSetW16(mem, 0, CB_MEML - iLBCdec_inst->state_short_len);
WEBRTC_SPL_MEMCPY_W16(mem+CB_MEML-iLBCdec_inst->state_short_len, decresidual+start_pos,
iLBCdec_inst->state_short_len);
/* construct decoded vector */
if (!WebRtcIlbcfix_CbConstruct(
&decresidual[start_pos + iLBCdec_inst->state_short_len],
iLBC_encbits->cb_index, iLBC_encbits->gain_index,
mem + CB_MEML - ST_MEM_L_TBL, ST_MEM_L_TBL, diff))
return false; // Error.
}
else {/* put adaptive part in the beginning */
/* setup memory */
meml_gotten = iLBCdec_inst->state_short_len;
WebRtcSpl_MemCpyReversedOrder(mem+CB_MEML-1,
decresidual+start_pos, meml_gotten);
WebRtcSpl_MemSetW16(mem, 0, CB_MEML - meml_gotten);
/* construct decoded vector */
if (!WebRtcIlbcfix_CbConstruct(reverseDecresidual, iLBC_encbits->cb_index,
iLBC_encbits->gain_index,
mem + CB_MEML - ST_MEM_L_TBL, ST_MEM_L_TBL,
diff))
return false; // Error.
/* get decoded residual from reversed vector */
WebRtcSpl_MemCpyReversedOrder(&decresidual[start_pos-1],
reverseDecresidual, diff);
}
/* counter for predicted subframes */
subcount=1;
/* forward prediction of subframes */
if (iLBCdec_inst->nsub > iLBC_encbits->startIdx + 1) {
/* setup memory */
WebRtcSpl_MemSetW16(mem, 0, CB_MEML-STATE_LEN);
WEBRTC_SPL_MEMCPY_W16(mem+CB_MEML-STATE_LEN,
decresidual+(iLBC_encbits->startIdx-1)*SUBL, STATE_LEN);
/* loop over subframes to encode */
size_t Nfor = iLBCdec_inst->nsub - iLBC_encbits->startIdx - 1;
for (subframe=0; subframe<Nfor; subframe++) {
/* construct decoded vector */
if (!WebRtcIlbcfix_CbConstruct(
&decresidual[(iLBC_encbits->startIdx + 1 + subframe) * SUBL],
iLBC_encbits->cb_index + subcount * CB_NSTAGES,
iLBC_encbits->gain_index + subcount * CB_NSTAGES, mem, MEM_LF_TBL,
SUBL))
return false; // Error;
/* update memory */
memmove(mem, mem + SUBL, (CB_MEML - SUBL) * sizeof(*mem));
WEBRTC_SPL_MEMCPY_W16(mem+CB_MEML-SUBL,
&decresidual[(iLBC_encbits->startIdx+1+subframe)*SUBL], SUBL);
subcount++;
}
}
/* backward prediction of subframes */
if (iLBC_encbits->startIdx > 1) {
/* setup memory */
meml_gotten = SUBL*(iLBCdec_inst->nsub+1-iLBC_encbits->startIdx);
if( meml_gotten > CB_MEML ) {
meml_gotten=CB_MEML;
}
WebRtcSpl_MemCpyReversedOrder(mem+CB_MEML-1,
decresidual+(iLBC_encbits->startIdx-1)*SUBL, meml_gotten);
WebRtcSpl_MemSetW16(mem, 0, CB_MEML - meml_gotten);
/* loop over subframes to decode */
size_t Nback = iLBC_encbits->startIdx - 1;
for (subframe=0; subframe<Nback; subframe++) {
/* construct decoded vector */
if (!WebRtcIlbcfix_CbConstruct(
&reverseDecresidual[subframe * SUBL],
iLBC_encbits->cb_index + subcount * CB_NSTAGES,
iLBC_encbits->gain_index + subcount * CB_NSTAGES, mem, MEM_LF_TBL,
SUBL))
return false; // Error.
/* update memory */
memmove(mem, mem + SUBL, (CB_MEML - SUBL) * sizeof(*mem));
WEBRTC_SPL_MEMCPY_W16(mem+CB_MEML-SUBL,
&reverseDecresidual[subframe*SUBL], SUBL);
subcount++;
}
/* get decoded residual from reversed vector */
WebRtcSpl_MemCpyReversedOrder(decresidual+SUBL*Nback-1,
reverseDecresidual, SUBL*Nback);
}
return true; // Success.
}