ref: 88e5cdc5ad86113e916b82dac813f6a21e2f7786
dir: /silk/decode_core.c/
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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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.
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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
}