ref: 103302b3752609e28cb6ba4f706a6f6e49ffef68
dir: /silk/silk_decode_indices.c/
/***********************************************************************
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are permitted provided that the following conditions are met:
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- Redistributions in binary form must reproduce the above copyright
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BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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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 );
}