ref: cc3405045567b70e816e91e9f130b8d8fff36d19
dir: /silk/decode_parameters.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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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "main.h"
/* Decode parameters from payload */
void silk_decode_parameters(
silk_decoder_state *psDec, /* I/O State */
silk_decoder_control *psDecCtrl /* I/O Decoder control */
)
{
opus_int i, k, Ix;
opus_int16 pNLSF_Q15[ MAX_LPC_ORDER ], pNLSF0_Q15[ MAX_LPC_ORDER ];
const opus_int8 *cbk_ptr_Q7;
/* Dequant Gains */
silk_gains_dequant( psDecCtrl->Gains_Q16, psDec->indices.GainsIndices,
&psDec->LastGainIndex, psDec->nFramesDecoded, psDec->nb_subfr );
/****************/
/* Decode NLSFs */
/****************/
silk_NLSF_decode( pNLSF_Q15, psDec->indices.NLSFIndices, psDec->psNLSF_CB );
/* Convert NLSF parameters to AR prediction filter coefficients */
silk_NLSF2A( psDecCtrl->PredCoef_Q12[ 1 ], pNLSF_Q15, psDec->LPC_order );
/* If just reset, e.g., because internal Fs changed, do not allow interpolation */
/* improves the case of packet loss in the first frame after a switch */
if( psDec->first_frame_after_reset == 1 ) {
psDec->indices.NLSFInterpCoef_Q2 = 4;
}
if( psDec->indices.NLSFInterpCoef_Q2 < 4 ) {
/* Calculation of the interpolated NLSF0 vector from the interpolation factor, */
/* the previous NLSF1, and the current NLSF1 */
for( i = 0; i < psDec->LPC_order; i++ ) {
pNLSF0_Q15[ i ] = psDec->prevNLSF_Q15[ i ] + silk_RSHIFT( silk_MUL( psDec->indices.NLSFInterpCoef_Q2,
pNLSF_Q15[ i ] - psDec->prevNLSF_Q15[ i ] ), 2 );
}
/* Convert NLSF parameters to AR prediction filter coefficients */
silk_NLSF2A( psDecCtrl->PredCoef_Q12[ 0 ], pNLSF0_Q15, psDec->LPC_order );
} else {
/* Copy LPC coefficients for first half from second half */
silk_memcpy( psDecCtrl->PredCoef_Q12[ 0 ], psDecCtrl->PredCoef_Q12[ 1 ],
psDec->LPC_order * sizeof( opus_int16 ) );
}
silk_memcpy( psDec->prevNLSF_Q15, pNLSF_Q15, psDec->LPC_order * sizeof( opus_int16 ) );
/* After a packet loss do BWE of LPC coefs */
if( psDec->lossCnt ) {
silk_bwexpander( psDecCtrl->PredCoef_Q12[ 0 ], psDec->LPC_order, BWE_AFTER_LOSS_Q16 );
silk_bwexpander( psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order, BWE_AFTER_LOSS_Q16 );
}
if( psDec->indices.signalType == TYPE_VOICED ) {
/*********************/
/* Decode pitch lags */
/*********************/
/* Decode pitch values */
silk_decode_pitch( psDec->indices.lagIndex, psDec->indices.contourIndex, psDecCtrl->pitchL, psDec->fs_kHz, psDec->nb_subfr );
/* Decode Codebook Index */
cbk_ptr_Q7 = silk_LTP_vq_ptrs_Q7[ psDec->indices.PERIndex ]; /* set pointer to start of codebook */
for( k = 0; k < psDec->nb_subfr; k++ ) {
Ix = psDec->indices.LTPIndex[ k ];
for( i = 0; i < LTP_ORDER; i++ ) {
psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER + i ] = silk_LSHIFT( cbk_ptr_Q7[ Ix * LTP_ORDER + i ], 7 );
}
}
/**********************/
/* Decode LTP scaling */
/**********************/
Ix = psDec->indices.LTP_scaleIndex;
psDecCtrl->LTP_scale_Q14 = silk_LTPScales_table_Q14[ Ix ];
} else {
silk_memset( psDecCtrl->pitchL, 0, psDec->nb_subfr * sizeof( opus_int ) );
silk_memset( psDecCtrl->LTPCoef_Q14, 0, LTP_ORDER * psDec->nb_subfr * sizeof( opus_int16 ) );
psDec->indices.PERIndex = 0;
psDecCtrl->LTP_scale_Q14 = 0;
}
}