ref: 4570db6af307d016d789124ad8b1990f07a8b6c7
dir: /silk/silk_decode_core.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
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
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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.
***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "silk_main.h"
/**********************************************************/
/* Core decoder. Performs inverse NSQ operation LTP + LPC */
/**********************************************************/
void silk_decode_core(
silk_decoder_state *psDec, /* I/O Decoder state */
silk_decoder_control *psDecCtrl, /* I Decoder control */
opus_int16 xq[], /* O Decoded speech */
const opus_int pulses[ MAX_FRAME_LENGTH ] /* I Pulse signal */
)
{
opus_int i, j, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType;
opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ];
opus_int16 sLTP[ MAX_FRAME_LENGTH ];
opus_int32 LTP_pred_Q14, LPC_pred_Q10, Gain_Q16, inv_gain_Q16, inv_gain_Q32, gain_adj_Q16, rand_seed, offset_Q10;
opus_int32 *pred_lag_ptr, *pexc_Q10, *pres_Q10;
opus_int32 res_Q10[ MAX_SUB_FRAME_LENGTH ];
opus_int32 vec_Q10[ MAX_SUB_FRAME_LENGTH ];
SKP_assert( psDec->prev_inv_gain_Q16 != 0 );
offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];
if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) {
NLSF_interpolation_flag = 1;
} else {
NLSF_interpolation_flag = 0;
}
/* Decode excitation */
rand_seed = psDec->indices.Seed;
for( i = 0; i < psDec->frame_length; i++ ) {
rand_seed = SKP_RAND( rand_seed );
psDec->exc_Q10[ i ] = SKP_LSHIFT( ( opus_int32 )pulses[ i ], 10 );
if( psDec->exc_Q10[ i ] > 0 ) {
psDec->exc_Q10[ i ] -= QUANT_LEVEL_ADJUST_Q10;
} else
if( psDec->exc_Q10[ i ] < 0 ) {
psDec->exc_Q10[ i ] += QUANT_LEVEL_ADJUST_Q10;
}
psDec->exc_Q10[ i ] += offset_Q10;
psDec->exc_Q10[ i ] ^= SKP_RSHIFT( rand_seed, 31 );
rand_seed += pulses[ i ];
}
#ifdef SAVE_ALL_INTERNAL_DATA
DEBUG_STORE_DATA( dec_q.dat, pulses, psDec->frame_length * sizeof( opus_int ) );
#endif
pexc_Q10 = psDec->exc_Q10;
pxq = &psDec->outBuf[ psDec->ltp_mem_length ];
sLTP_buf_idx = psDec->ltp_mem_length;
/* Loop over subframes */
for( k = 0; k < psDec->nb_subfr; k++ ) {
pres_Q10 = res_Q10;
A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ];
/* Preload LPC coeficients to array on stack. Gives small performance gain */
SKP_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ];
Gain_Q16 = psDecCtrl->Gains_Q16[ k ];
signalType = psDec->indices.signalType;
inv_gain_Q16 = silk_INVERSE32_varQ( SKP_max( Gain_Q16, 1 ), 32 );
inv_gain_Q16 = SKP_min( inv_gain_Q16, SKP_int16_MAX );
/* Calculate Gain adjustment factor */
gain_adj_Q16 = 1 << 16;
if( inv_gain_Q16 != psDec->prev_inv_gain_Q16 ) {
gain_adj_Q16 = silk_DIV32_varQ( inv_gain_Q16, psDec->prev_inv_gain_Q16, 16 );
/* Scale short term state */
for( i = 0; i < MAX_LPC_ORDER; i++ ) {
psDec->sLPC_Q14[ i ] = SKP_SMULWW( gain_adj_Q16, psDec->sLPC_Q14[ i ] );
}
}
/* Save inv_gain */
SKP_assert( inv_gain_Q16 != 0 );
psDec->prev_inv_gain_Q16 = inv_gain_Q16;
/* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */
if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED &&
psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) {
SKP_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 );
signalType = TYPE_VOICED;
psDecCtrl->pitchL[ k ] = psDec->lagPrev;
}
if( signalType == TYPE_VOICED ) {
/* Voiced */
lag = psDecCtrl->pitchL[ k ];
/* Re-whitening */
if( ( k & ( 3 - SKP_LSHIFT( NLSF_interpolation_flag, 1 ) ) ) == 0 ) {
/* Rewhiten with new A coefs */
start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
SKP_assert( start_idx > 0 );
silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ],
A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order );
/* After rewhitening the LTP state is unscaled */
inv_gain_Q32 = SKP_LSHIFT( inv_gain_Q16, 16 );
if( k == 0 ) {
/* Do LTP downscaling */
inv_gain_Q32 = SKP_LSHIFT( SKP_SMULWB( inv_gain_Q32, psDecCtrl->LTP_scale_Q14 ), 2 );
}
for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
psDec->sLTP_Q16[ sLTP_buf_idx - i - 1 ] = SKP_SMULWB( inv_gain_Q32, sLTP[ psDec->ltp_mem_length - i - 1 ] );
}
} else {
/* Update LTP state when Gain changes */
if( gain_adj_Q16 != 1 << 16 ) {
for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
psDec->sLTP_Q16[ sLTP_buf_idx - i - 1 ] = SKP_SMULWW( gain_adj_Q16, psDec->sLTP_Q16[ sLTP_buf_idx - i - 1 ] );
}
}
}
}
/* Long-term prediction */
if( signalType == TYPE_VOICED ) {
/* Setup pointer */
pred_lag_ptr = &psDec->sLTP_Q16[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
for( i = 0; i < psDec->subfr_length; i++ ) {
/* Unrolled loop */
LTP_pred_Q14 = SKP_SMULWB( pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
pred_lag_ptr++;
/* Generate LPC excitation */
pres_Q10[ i ] = SKP_ADD32( pexc_Q10[ i ], SKP_RSHIFT_ROUND( LTP_pred_Q14, 4 ) );
/* Update states */
psDec->sLTP_Q16[ sLTP_buf_idx ] = SKP_LSHIFT( pres_Q10[ i ], 6 );
sLTP_buf_idx++;
}
} else {
pres_Q10 = pexc_Q10;
}
#ifdef SAVE_ALL_INTERNAL_DATA
DEBUG_STORE_DATA( dec_exc_Q10.dat, pexc_Q10, psDec->subfr_length * sizeof( opus_int32 ) );
DEBUG_STORE_DATA( dec_res_Q10.dat, pres_Q10, psDec->subfr_length * sizeof( opus_int32 ) );
#endif
for( i = 0; i < psDec->subfr_length; i++ ) {
/* Partially unrolled */
LPC_pred_Q10 = SKP_SMULWB( psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
for( j = 10; j < psDec->LPC_order; j++ ) {
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - j - 1 ], A_Q12_tmp[ j ] );
}
/* Add prediction to LPC excitation */
vec_Q10[ i ] = SKP_ADD32( pres_Q10[ i ], LPC_pred_Q10 );
/* Update states */
psDec->sLPC_Q14[ MAX_LPC_ORDER + i ] = SKP_LSHIFT( vec_Q10[ i ], 4 );
}
/* Scale with Gain */
for( i = 0; i < psDec->subfr_length; i++ ) {
pxq[ i ] = ( opus_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SMULWW( vec_Q10[ i ], Gain_Q16 ), 10 ) );
}
/* Update LPC filter state */
SKP_memcpy( psDec->sLPC_Q14, &psDec->sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
pexc_Q10 += psDec->subfr_length;
pxq += psDec->subfr_length;
}
/* Copy to output */
SKP_memcpy( xq, &psDec->outBuf[ psDec->ltp_mem_length ], psDec->frame_length * sizeof( opus_int16 ) );
#ifdef SAVE_ALL_INTERNAL_DATA
DEBUG_STORE_DATA( dec_sLTP_Q16.dat, &psDec->sLTP_Q16[ psDec->ltp_mem_length ], psDec->frame_length * sizeof( opus_int32 ));
DEBUG_STORE_DATA( dec_xq.dat, xq, psDec->frame_length * sizeof( opus_int16 ) );
#endif
}