/*
* Copyright (c) 2012 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_Decode.c
******************************************************************/
#include "defines.h"
#include "simple_lsf_dequant.h"
#include "decoder_interpolate_lsf.h"
#include "index_conv_dec.h"
#include "do_plc.h"
#include "constants.h"
#include "enhancer_interface.h"
#include "xcorr_coef.h"
#include "lsf_check.h"
#include "decode_residual.h"
#include "unpack_bits.h"
#include "hp_output.h"
#ifndef WEBRTC_ARCH_BIG_ENDIAN
#include "swap_bytes.h"
#endif
/*----------------------------------------------------------------*
* main decoder function
*---------------------------------------------------------------*/
void WebRtcIlbcfix_DecodeImpl(
int16_t *decblock, /* (o) decoded signal block */
const uint16_t *bytes, /* (i) encoded signal bits */
iLBC_Dec_Inst_t *iLBCdec_inst, /* (i/o) the decoder state
structure */
int16_t mode /* (i) 0: bad packet, PLC,
1: normal */
) {
int i;
int16_t order_plus_one;
int16_t last_bit;
int16_t *data;
/* Stack based */
int16_t decresidual[BLOCKL_MAX];
int16_t PLCresidual[BLOCKL_MAX + LPC_FILTERORDER];
int16_t syntdenum[NSUB_MAX*(LPC_FILTERORDER+1)];
int16_t PLClpc[LPC_FILTERORDER + 1];
#ifndef WEBRTC_ARCH_BIG_ENDIAN
uint16_t swapped[NO_OF_WORDS_30MS];
#endif
iLBC_bits *iLBCbits_inst = (iLBC_bits*)PLCresidual;
/* Reuse some buffers that are non overlapping in order to save stack memory */
data = &PLCresidual[LPC_FILTERORDER];
if (mode) { /* the data are good */
/* decode data */
/* Unpacketize bits into parameters */
#ifndef WEBRTC_ARCH_BIG_ENDIAN
WebRtcIlbcfix_SwapBytes(bytes, iLBCdec_inst->no_of_words, swapped);
last_bit = WebRtcIlbcfix_UnpackBits(swapped, iLBCbits_inst, iLBCdec_inst->mode);
#else
last_bit = WebRtcIlbcfix_UnpackBits(bytes, iLBCbits_inst, iLBCdec_inst->mode);
#endif
/* Check for bit errors */
if (iLBCbits_inst->startIdx<1)
mode = 0;
if ((iLBCdec_inst->mode==20) && (iLBCbits_inst->startIdx>3))
mode = 0;
if ((iLBCdec_inst->mode==30) && (iLBCbits_inst->startIdx>5))
mode = 0;
if (last_bit==1)
mode = 0;
if (mode) { /* No bit errors was detected, continue decoding */
/* Stack based */
int16_t lsfdeq[LPC_FILTERORDER*LPC_N_MAX];
int16_t weightdenum[(LPC_FILTERORDER + 1)*NSUB_MAX];
/* adjust index */
WebRtcIlbcfix_IndexConvDec(iLBCbits_inst->cb_index);
/* decode the lsf */
WebRtcIlbcfix_SimpleLsfDeQ(lsfdeq, (int16_t*)(iLBCbits_inst->lsf), iLBCdec_inst->lpc_n);
WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCdec_inst->lpc_n);
WebRtcIlbcfix_DecoderInterpolateLsp(syntdenum, weightdenum,
lsfdeq, LPC_FILTERORDER, iLBCdec_inst);
/* Decode the residual using the cb and gain indexes */
WebRtcIlbcfix_DecodeResidual(iLBCdec_inst, iLBCbits_inst, decresidual, syntdenum);
/* preparing the plc for a future loss! */
WebRtcIlbcfix_DoThePlc( PLCresidual, PLClpc, 0,
decresidual, syntdenum + (LPC_FILTERORDER + 1)*(iLBCdec_inst->nsub - 1),
(int16_t)(iLBCdec_inst->last_lag), iLBCdec_inst);
/* Use the output from doThePLC */
WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl);
}
}
if (mode == 0) {
/* the data is bad (either a PLC call
* was made or a bit error was detected)
*/
/* packet loss conceal */
WebRtcIlbcfix_DoThePlc( PLCresidual, PLClpc, 1,
decresidual, syntdenum, (int16_t)(iLBCdec_inst->last_lag), iLBCdec_inst);
WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl);
order_plus_one = LPC_FILTERORDER + 1;
for (i = 0; i < iLBCdec_inst->nsub; i++) {
WEBRTC_SPL_MEMCPY_W16(syntdenum+(i*order_plus_one),
PLClpc, order_plus_one);
}
}
if ((*iLBCdec_inst).use_enhancer == 1) { /* Enhancer activated */
/* Update the filter and filter coefficients if there was a packet loss */
if (iLBCdec_inst->prev_enh_pl==2) {
for (i=0;i<iLBCdec_inst->nsub;i++) {
WEBRTC_SPL_MEMCPY_W16(&(iLBCdec_inst->old_syntdenum[i*(LPC_FILTERORDER+1)]),
syntdenum, (LPC_FILTERORDER+1));
}
}
/* post filtering */
(*iLBCdec_inst).last_lag =
WebRtcIlbcfix_EnhancerInterface(data, decresidual, iLBCdec_inst);
/* synthesis filtering */
/* Set up the filter state */
WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER);
if (iLBCdec_inst->mode==20) {
/* Enhancer has 40 samples delay */
i=0;
WebRtcSpl_FilterARFastQ12(
data, data,
iLBCdec_inst->old_syntdenum + (i+iLBCdec_inst->nsub-1)*(LPC_FILTERORDER+1),
LPC_FILTERORDER+1, SUBL);
for (i=1; i < iLBCdec_inst->nsub; i++) {
WebRtcSpl_FilterARFastQ12(
data+i*SUBL, data+i*SUBL,
syntdenum+(i-1)*(LPC_FILTERORDER+1),
LPC_FILTERORDER+1, SUBL);
}
} else if (iLBCdec_inst->mode==30) {
/* Enhancer has 80 samples delay */
for (i=0; i < 2; i++) {
WebRtcSpl_FilterARFastQ12(
data+i*SUBL, data+i*SUBL,
iLBCdec_inst->old_syntdenum + (i+4)*(LPC_FILTERORDER+1),
LPC_FILTERORDER+1, SUBL);
}
for (i=2; i < iLBCdec_inst->nsub; i++) {
WebRtcSpl_FilterARFastQ12(
data+i*SUBL, data+i*SUBL,
syntdenum+(i-2)*(LPC_FILTERORDER+1),
LPC_FILTERORDER+1, SUBL);
}
}
/* Save the filter state */
WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER);
} else { /* Enhancer not activated */
int16_t lag;
/* Find last lag (since the enhancer is not called to give this info) */
lag = 20;
if (iLBCdec_inst->mode==20) {
lag = (int16_t)WebRtcIlbcfix_XcorrCoef(
&decresidual[iLBCdec_inst->blockl-60],
&decresidual[iLBCdec_inst->blockl-60-lag],
60,
80, lag, -1);
} else {
lag = (int16_t)WebRtcIlbcfix_XcorrCoef(
&decresidual[iLBCdec_inst->blockl-ENH_BLOCKL],
&decresidual[iLBCdec_inst->blockl-ENH_BLOCKL-lag],
ENH_BLOCKL,
100, lag, -1);
}
/* Store lag (it is needed if next packet is lost) */
(*iLBCdec_inst).last_lag = (int)lag;
/* copy data and run synthesis filter */
WEBRTC_SPL_MEMCPY_W16(data, decresidual, iLBCdec_inst->blockl);
/* Set up the filter state */
WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER);
for (i=0; i < iLBCdec_inst->nsub; i++) {
WebRtcSpl_FilterARFastQ12(
data+i*SUBL, data+i*SUBL,
syntdenum + i*(LPC_FILTERORDER+1),
LPC_FILTERORDER+1, SUBL);
}
/* Save the filter state */
WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER);
}
WEBRTC_SPL_MEMCPY_W16(decblock,data,iLBCdec_inst->blockl);
/* High pass filter the signal (with upscaling a factor 2 and saturation) */
WebRtcIlbcfix_HpOutput(decblock, (int16_t*)WebRtcIlbcfix_kHpOutCoefs,
iLBCdec_inst->hpimemy, iLBCdec_inst->hpimemx,
iLBCdec_inst->blockl);
WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->old_syntdenum,
syntdenum, iLBCdec_inst->nsub*(LPC_FILTERORDER+1));
iLBCdec_inst->prev_enh_pl=0;
if (mode==0) { /* PLC was used */
iLBCdec_inst->prev_enh_pl=1;
}
}