ref: 8cb54e11ca0663206fec0f9e36c07260f83fdf95
dir: /silk/silk_decode_indices.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:
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this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
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documentation and/or other materials provided with the distribution.
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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
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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 "silk_main.h"
/* Decode side-information parameters from payload */
void silk_decode_indices(
silk_decoder_state *psDec, /* I/O State */
ec_dec *psRangeDec, /* I/O Compressor data structure */
SKP_int FrameIndex, /* I Frame number */
SKP_int decode_LBRR /* I Flag indicating LBRR data is being decoded */
)
{
SKP_int i, k, Ix, condCoding;
SKP_int decode_absolute_lagIndex, delta_lagIndex;
SKP_int16 ec_ix[ MAX_LPC_ORDER ];
SKP_uint8 pred_Q8[ MAX_LPC_ORDER ];
/* Use conditional coding if previous frame available */
if( FrameIndex > 0 && ( decode_LBRR == 0 || psDec->LBRR_flags[ FrameIndex - 1 ] == 1 ) ) {
condCoding = 1;
} else {
condCoding = 0;
}
/*******************************************/
/* Decode signal type and quantizer offset */
/*******************************************/
if( decode_LBRR || psDec->VAD_flags[ FrameIndex ] ) {
Ix = ec_dec_icdf( psRangeDec, silk_type_offset_VAD_iCDF, 8 ) + 2;
} else {
Ix = ec_dec_icdf( psRangeDec, silk_type_offset_no_VAD_iCDF, 8 );
}
psDec->indices.signalType = (SKP_int8)SKP_RSHIFT( Ix, 1 );
psDec->indices.quantOffsetType = (SKP_int8)( Ix & 1 );
/****************/
/* Decode gains */
/****************/
/* First subframe */
if( condCoding ) {
/* Conditional coding */
psDec->indices.GainsIndices[ 0 ] = (SKP_int8)ec_dec_icdf( psRangeDec, silk_delta_gain_iCDF, 8 );
} else {
/* Independent coding, in two stages: MSB bits followed by 3 LSBs */
psDec->indices.GainsIndices[ 0 ] = (SKP_int8)SKP_LSHIFT( ec_dec_icdf( psRangeDec, silk_gain_iCDF[ psDec->indices.signalType ], 8 ), 3 );
psDec->indices.GainsIndices[ 0 ] += (SKP_int8)ec_dec_icdf( psRangeDec, silk_uniform8_iCDF, 8 );
}
/* Remaining subframes */
for( i = 1; i < psDec->nb_subfr; i++ ) {
psDec->indices.GainsIndices[ i ] = (SKP_int8)ec_dec_icdf( psRangeDec, silk_delta_gain_iCDF, 8 );
}
/**********************/
/* Decode LSF Indices */
/**********************/
psDec->indices.NLSFIndices[ 0 ] = (SKP_int8)ec_dec_icdf( psRangeDec, &psDec->psNLSF_CB->CB1_iCDF[ ( psDec->indices.signalType >> 1 ) * psDec->psNLSF_CB->nVectors ], 8 );
silk_NLSF_unpack( ec_ix, pred_Q8, psDec->psNLSF_CB, psDec->indices.NLSFIndices[ 0 ] );
SKP_assert( psDec->psNLSF_CB->order == psDec->LPC_order );
for( i = 0; i < psDec->psNLSF_CB->order; i++ ) {
Ix = ec_dec_icdf( psRangeDec, &psDec->psNLSF_CB->ec_iCDF[ ec_ix[ i ] ], 8 );
if( Ix == 0 ) {
Ix -= ec_dec_icdf( psRangeDec, silk_NLSF_EXT_iCDF, 8 );
} else if( Ix == 2 * NLSF_QUANT_MAX_AMPLITUDE ) {
Ix += ec_dec_icdf( psRangeDec, silk_NLSF_EXT_iCDF, 8 );
}
psDec->indices.NLSFIndices[ i+1 ] = (SKP_int8)( Ix - NLSF_QUANT_MAX_AMPLITUDE );
}
/* Decode LSF interpolation factor */
if( psDec->nb_subfr == MAX_NB_SUBFR ) {
psDec->indices.NLSFInterpCoef_Q2 = (SKP_int8)ec_dec_icdf( psRangeDec, silk_NLSF_interpolation_factor_iCDF, 8 );
} else {
psDec->indices.NLSFInterpCoef_Q2 = 4;
}
if( psDec->indices.signalType == TYPE_VOICED )
{
/*********************/
/* Decode pitch lags */
/*********************/
/* Get lag index */
decode_absolute_lagIndex = 1;
if( condCoding && psDec->ec_prevSignalType == TYPE_VOICED ) {
/* Decode Delta index */
delta_lagIndex = (SKP_int16)ec_dec_icdf( psRangeDec, silk_pitch_delta_iCDF, 8 );
if( delta_lagIndex > 0 ) {
delta_lagIndex = delta_lagIndex - 9;
psDec->indices.lagIndex = (SKP_int16)( psDec->ec_prevLagIndex + delta_lagIndex );
decode_absolute_lagIndex = 0;
}
}
if( decode_absolute_lagIndex ) {
/* Absolute decoding */
psDec->indices.lagIndex = (SKP_int16)ec_dec_icdf( psRangeDec, silk_pitch_lag_iCDF, 8 ) * SKP_RSHIFT( psDec->fs_kHz, 1 );
psDec->indices.lagIndex += (SKP_int16)ec_dec_icdf( psRangeDec, psDec->pitch_lag_low_bits_iCDF, 8 );
}
psDec->ec_prevLagIndex = psDec->indices.lagIndex;
/* Get countour index */
psDec->indices.contourIndex = (SKP_int8)ec_dec_icdf( psRangeDec, psDec->pitch_contour_iCDF, 8 );
/********************/
/* Decode LTP gains */
/********************/
/* Decode PERIndex value */
psDec->indices.PERIndex = (SKP_int8)ec_dec_icdf( psRangeDec, silk_LTP_per_index_iCDF, 8 );
for( k = 0; k < psDec->nb_subfr; k++ ) {
psDec->indices.LTPIndex[ k ] = (SKP_int8)ec_dec_icdf( psRangeDec, silk_LTP_gain_iCDF_ptrs[ psDec->indices.PERIndex ], 8 );
}
/**********************/
/* Decode LTP scaling */
/**********************/
if( !condCoding ) {
psDec->indices.LTP_scaleIndex = (SKP_int8)ec_dec_icdf( psRangeDec, silk_LTPscale_iCDF, 8 );
} else {
psDec->indices.LTP_scaleIndex = 0;
}
}
psDec->ec_prevSignalType = psDec->indices.signalType;
/***************/
/* Decode seed */
/***************/
psDec->indices.Seed = (SKP_int8)ec_dec_icdf( psRangeDec, silk_uniform4_iCDF, 8 );
}