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Improves the accuracy such that it matches a float decoder much better

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Koen Vos 2011-12-13 14:50:12 -05:00 • committed by Jean-Marc Valin
parent bf75c8ec4d
commit bbfc9c9ee5
17 changed files with 132 additions and 104 deletions
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31
silk/decode_core.c
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@ -45,12 +45,12 @@ void silk_decode_core(
opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ];
opus_int16 sLTP[ MAX_FRAME_LENGTH ];
opus_int32 sLTP_Q15[ 2 * MAX_FRAME_LENGTH ];
opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q16, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10;
opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, 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 );
silk_assert( psDec->prev_inv_gain_Q31 != 0 );
offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];
@ -94,22 +94,23 @@ void silk_decode_core(
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_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 );
/* 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 );
/* Calculate gain adjustment factor */
if( inv_gain_Q31 != psDec->prev_inv_gain_Q31 ) {
gain_adj_Q16 = silk_DIV32_varQ( inv_gain_Q31, psDec->prev_inv_gain_Q31, 16 );
/* Scale short term state */
for( i = 0; i < MAX_LPC_ORDER; i++ ) {
sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] );
}
} else {
gain_adj_Q16 = 1 << 16;
}
/* Save inv_gain */
silk_assert( inv_gain_Q16 != 0 );
psDec->prev_inv_gain_Q16 = inv_gain_Q16;
silk_assert( inv_gain_Q31 != 0 );
psDec->prev_inv_gain_Q31 = inv_gain_Q31;
/* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */
if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED &&
@ -140,7 +141,6 @@ void silk_decode_core(
A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order );
/* After rewhitening the LTP state is unscaled */
inv_gain_Q31 = silk_LSHIFT( inv_gain_Q16, 15 );
if( k == 0 ) {
/* Do LTP downscaling to reduce inter-packet dependency */
inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 );
@ -164,7 +164,9 @@ void silk_decode_core(
pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
for( i = 0; i < psDec->subfr_length; i++ ) {
/* Unrolled loop */
LTP_pred_Q13 = silk_SMULWB( pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
LTP_pred_Q13 = 2;
LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
@ -185,7 +187,9 @@ void silk_decode_core(
for( i = 0; i < psDec->subfr_length; i++ ) {
/* Short-term prediction */
silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
LPC_pred_Q10 = silk_SMULWB( sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, 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 ] );
@ -207,11 +211,12 @@ void silk_decode_core(
/* 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 */
/* Scale with gain */
pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) );
}
/* DEBUG_STORE_DATA( dec.pcm, pxq, psDec->subfr_length * sizeof( opus_int16 ) ) */
/* Update LPC filter state */
silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
pexc_Q10 += psDec->subfr_length;