ref: f7479653be7649267fd9e2096adf47862cea1a95
dir: /src_common/SKP_Silk_decode_frame.c/
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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modification, (subject to the limitations in the disclaimer below)
are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of Skype Limited, nor the names of specific
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this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/
#include "SKP_Silk_main.h"
#include "SKP_Silk_PLC.h"
#define DECODE_NORMAL 0
#define PACKET_LOST 1
#define DECODE_LBRR 2
/****************/
/* Decode frame */
/****************/
SKP_int SKP_Silk_decode_frame(
SKP_Silk_decoder_state *psDec, /* I/O Pointer to Silk decoder state */
ec_dec *psRangeDec, /* I/O Compressor data structure */
SKP_int16 pOut[], /* O Pointer to output speech frame */
SKP_int32 *pN, /* O Pointer to size of output frame */
const SKP_int nBytes, /* I Payload length */
SKP_int lostFlag /* I 0: no loss, 1 loss, 2 decode fec */
)
{
SKP_Silk_decoder_control sDecCtrl;
SKP_int i, L, mv_len, ret = 0;
SKP_int8 flags;
SKP_int32 LBRR_symbol;
SKP_int pulses[ MAX_FRAME_LENGTH ];
TIC(DECODE_FRAME)
L = psDec->frame_length;
sDecCtrl.LTP_scale_Q14 = 0;
/* Safety checks */
SKP_assert( L > 0 && L <= MAX_FRAME_LENGTH );
/********************************************/
/* Decode Frame if packet is not lost */
/********************************************/
if( lostFlag != PACKET_LOST && psDec->nFramesDecoded == 0 ) {
/* First decoder call for this payload */
/* Decode VAD flags and LBRR flag */
flags = SKP_RSHIFT( psRangeDec->buf[ 0 ], 7 - psDec->nFramesPerPacket ) &
( SKP_LSHIFT( 1, psDec->nFramesPerPacket + 1 ) - 1 );
psDec->LBRR_flag = flags & 1;
for( i = psDec->nFramesPerPacket - 1; i >= 0 ; i-- ) {
flags = SKP_RSHIFT( flags, 1 );
psDec->VAD_flags[ i ] = flags & 1;
}
for( i = 0; i < psDec->nFramesPerPacket + 1; i++ ) {
ec_dec_icdf( psRangeDec, SKP_Silk_uniform2_iCDF, 8 );
}
/* Decode LBRR flags */
SKP_memset( psDec->LBRR_flags, 0, sizeof( psDec->LBRR_flags ) );
if( psDec->LBRR_flag ) {
if( psDec->nFramesPerPacket == 1 ) {
psDec->LBRR_flags[ 0 ] = 1;
} else {
LBRR_symbol = ec_dec_icdf( psRangeDec, SKP_Silk_LBRR_flags_iCDF_ptr[ psDec->nFramesPerPacket - 2 ], 8 ) + 1;
for( i = 0; i < psDec->nFramesPerPacket; i++ ) {
psDec->LBRR_flags[ i ] = SKP_RSHIFT( LBRR_symbol, i ) & 1;
}
}
}
if( lostFlag == DECODE_NORMAL ) {
/* Regular decoding: skip all LBRR data */
for( i = 0; i < psDec->nFramesPerPacket; i++ ) {
if( psDec->LBRR_flags[ i ] ) {
SKP_Silk_decode_indices( psDec, psRangeDec, i, 1 );
SKP_Silk_decode_pulses( psRangeDec, pulses, psDec->indices.signalType,
psDec->indices.quantOffsetType, psDec->frame_length );
}
}
}
}
if( lostFlag == DECODE_LBRR && psDec->LBRR_flags[ psDec->nFramesDecoded ] == 0 ) {
/* Treat absent LBRR data as lost frame */
lostFlag = PACKET_LOST;
psDec->nFramesDecoded++;
}
if( lostFlag != PACKET_LOST ) {
/*********************************************/
/* Decode quantization indices of side info */
/*********************************************/
TIC(decode_indices)
SKP_Silk_decode_indices( psDec, psRangeDec, psDec->nFramesDecoded, lostFlag );
TOC(decode_indices)
/*********************************************/
/* Decode quantization indices of excitation */
/*********************************************/
TIC(decode_pulses)
SKP_Silk_decode_pulses( psRangeDec, pulses, psDec->indices.signalType,
psDec->indices.quantOffsetType, psDec->frame_length );
TOC(decode_pulses)
/********************************************/
/* Decode parameters and pulse signal */
/********************************************/
TIC(decode_params)
SKP_Silk_decode_parameters( psDec, &sDecCtrl );
TOC(decode_params)
/* Update length. Sampling frequency may have changed */
L = psDec->frame_length;
/********************************************************/
/* Run inverse NSQ */
/********************************************************/
TIC(decode_core)
SKP_Silk_decode_core( psDec, &sDecCtrl, pOut, pulses );
TOC(decode_core)
/********************************************************/
/* Update PLC state */
/********************************************************/
SKP_Silk_PLC( psDec, &sDecCtrl, pOut, L, 0 );
psDec->lossCnt = 0;
psDec->prevSignalType = psDec->indices.signalType;
SKP_assert( psDec->prevSignalType >= 0 && psDec->prevSignalType <= 2 );
/* A frame has been decoded without errors */
psDec->first_frame_after_reset = 0;
psDec->nFramesDecoded++;
} else {
/* Handle packet loss by extrapolation */
SKP_Silk_PLC( psDec, &sDecCtrl, pOut, L, 1 );
}
/*************************/
/* Update output buffer. */
/*************************/
SKP_assert( psDec->ltp_mem_length >= psDec->frame_length );
mv_len = psDec->ltp_mem_length - psDec->frame_length;
SKP_memmove( psDec->outBuf, &psDec->outBuf[ psDec->frame_length ], mv_len * sizeof(SKP_int16) );
SKP_memcpy( &psDec->outBuf[ mv_len ], pOut, psDec->frame_length * sizeof( SKP_int16 ) );
/****************************************************************/
/* Ensure smooth connection of extrapolated and good frames */
/****************************************************************/
SKP_Silk_PLC_glue_frames( psDec, &sDecCtrl, pOut, L );
/************************************************/
/* Comfort noise generation / estimation */
/************************************************/
SKP_Silk_CNG( psDec, &sDecCtrl, pOut, L );
/********************************************/
/* HP filter output */
/********************************************/
TIC(HP_out)
SKP_Silk_biquad_alt( pOut, psDec->HP_B, psDec->HP_A, psDec->HPState, pOut, L );
TOC(HP_out)
/* Update some decoder state variables */
psDec->lagPrev = sDecCtrl.pitchL[ psDec->nb_subfr - 1 ];
/********************************************/
/* set output frame length */
/********************************************/
*pN = ( SKP_int16 )L;
TOC(DECODE_FRAME)
return ret;
}