ref: 3d28ee802016ba5899bddea0cc511d79c7e5ea34
dir: /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
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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
CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
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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 "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 sLTP_Q16[ 2 * MAX_FRAME_LENGTH ];
opus_int32 LTP_pred_Q14, LPC_pred_Q10, Gain_Q10, 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 sLPC_Q14[ MAX_SUB_FRAME_LENGTH + MAX_LPC_ORDER ];
silk_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 = silk_RAND( rand_seed );
psDec->exc_Q10[ i ] = silk_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 ] ^= silk_RSHIFT( rand_seed, 31 );
rand_seed = silk_ADD32_ovflw(rand_seed, pulses[ i ]);
}
#ifdef SAVE_ALL_INTERNAL_DATA
DEBUG_STORE_DATA( dec_q.dat, pulses, psDec->frame_length * sizeof( opus_int ) );
#endif
/* Copy LPC state */
silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );
pexc_Q10 = psDec->exc_Q10;
pxq = xq;
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 */
silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ];
signalType = psDec->indices.signalType;
Gain_Q10 = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 );
inv_gain_Q16 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 32 );
inv_gain_Q16 = silk_min( inv_gain_Q16, silk_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++ ) {
sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] );
}
}
/* Save inv_gain */
silk_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 ) {
silk_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 == 0 || ( k == 2 && NLSF_interpolation_flag ) ) {
/* Rewhiten with new A coefs */
start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
silk_assert( start_idx > 0 );
if( k == 2 ) {
silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) );
}
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 = silk_LSHIFT( inv_gain_Q16, 16 );
if( k == 0 ) {
/* Do LTP downscaling to reduce inter-packet dependency */
inv_gain_Q32 = silk_LSHIFT( silk_SMULWB( inv_gain_Q32, psDecCtrl->LTP_scale_Q14 ), 2 );
}
for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
sLTP_Q16[ sLTP_buf_idx - i - 1 ] = silk_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++ ) {
sLTP_Q16[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q16[ sLTP_buf_idx - i - 1 ] );
}
}
}
}
/* Long-term prediction */
if( signalType == TYPE_VOICED ) {
/* Setup pointer */
pred_lag_ptr = &sLTP_Q16[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
for( i = 0; i < psDec->subfr_length; i++ ) {
/* Unrolled loop */
LTP_pred_Q14 = silk_SMULWB( pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
LTP_pred_Q14 = silk_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
pred_lag_ptr++;
/* Generate LPC excitation */
pres_Q10[ i ] = silk_ADD32( pexc_Q10[ i ], silk_RSHIFT_ROUND( LTP_pred_Q14, 4 ) );
/* Update states */
sLTP_Q16[ sLTP_buf_idx ] = silk_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 = silk_SMULWB( sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
for( j = 10; j < psDec->LPC_order; j++ ) {
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - j - 1 ], A_Q12_tmp[ j ] );
}
/* Add prediction to LPC excitation */
sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_LSHIFT( silk_ADD32( pres_Q10[ i ], LPC_pred_Q10 ), 4 );
/* Scale with Gain */
pxq[ i ] = ( opus_int16 )silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) );
}
/* Update LPC filter state */
silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
pexc_Q10 += psDec->subfr_length;
pxq += psDec->subfr_length;
}
/* Save LPC state */
silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) );
#ifdef SAVE_ALL_INTERNAL_DATA
DEBUG_STORE_DATA( dec_sLTP_Q16.dat, &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
}