diff options
author | Koen Vos <koen.vos@skype.net> | 2011-12-13 23:47:31 +0400 |
---|---|---|
committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-12-13 23:47:31 +0400 |
commit | bf75c8ec4d0dded188bc7793de6da56c7ff0be1c (patch) | |
tree | c21bb05faf0a203b73e8f8aae90fc63dac27625d /silk/decode_core.c | |
parent | 6619a736376221f2782cecff55d051c3ecfc2ff7 (diff) |
SILK fixes following last codec WG meeting
decoder:
- fixed incorrect scaling of filter states for the smallest quantization
step sizes
- NLSF2A now limits the prediction gain of LPC filters
encoder:
- increased damping of LTP coefficients in LTP analysis
- increased white noise fraction in noise shaping LPC analysis
- introduced maximum total prediction gain. Used by Burg's method to
exit early if prediction gain is exceeded. This improves packet
loss robustness and numerical robustness in Burg's method
- Prefiltered signal is now in int32 Q10 domain, from int16 Q0
- Increased max number of iterations in CBR gain control loop from 5 to 6
- Removed useless code from LTP scaling control
- Optimization: smarter LPC loop unrolling
- Switched default win32 compile mode to be floating-point
resampler:
- made resampler have constant delay of 0.75 ms; removed delay
compensation from silk code.
- removed obsolete table entries (~850 Bytes)
- increased downsampling filter order from 16 to 18/24/36 (depending on
frequency ratio)
- reoptimized filter coefficients
Diffstat (limited to 'silk/decode_core.c')
-rw-r--r-- | silk/decode_core.c | 50 |
1 files changed, 28 insertions, 22 deletions
diff --git a/silk/decode_core.c b/silk/decode_core.c index 9a4c9f39..6633143d 100644 --- a/silk/decode_core.c +++ b/silk/decode_core.c @@ -41,11 +41,11 @@ void silk_decode_core( 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_int i, 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 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 *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 ]; @@ -64,7 +64,7 @@ void silk_decode_core( 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 ); + 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 @@ -95,7 +95,6 @@ void silk_decode_core( 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; @@ -141,19 +140,19 @@ void silk_decode_core( 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 ); + inv_gain_Q31 = silk_LSHIFT( inv_gain_Q16, 15 ); 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 ); + inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, 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 ] ); + sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, 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 ] ); + sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] ); } } } @@ -161,22 +160,22 @@ void silk_decode_core( /* Long-term prediction */ if( signalType == TYPE_VOICED ) { - /* Setup pointer */ - pred_lag_ptr = &sLTP_Q16[ sLTP_buf_idx - lag + LTP_ORDER / 2 ]; + /* Set up pointer */ + pred_lag_ptr = &sLTP_Q15[ 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 ] ); + LTP_pred_Q13 = silk_SMULWB( 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 ] ); + LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, 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 ) ); + pres_Q10[ i ] = silk_ADD32( pexc_Q10[ i ], silk_RSHIFT_ROUND( LTP_pred_Q13, 3 ) ); /* Update states */ - sLTP_Q16[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q10[ i ], 6 ); + sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q10[ i ], 5 ); sLTP_buf_idx++; } } else { @@ -184,7 +183,8 @@ void silk_decode_core( } for( i = 0; i < psDec->subfr_length; i++ ) { - /* Partially unrolled */ + /* 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 ] ); 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 ] ); @@ -195,17 +195,23 @@ void silk_decode_core( 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 ] ); + if( psDec->LPC_order == 16 ) { + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] ); + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] ); + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] ); + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] ); + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] ); + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] ); } /* 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 ) ); + 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; |