diff options
author | Koen Vos <koen.vos@skype.net> | 2011-12-13 23:50:12 +0400 |
---|---|---|
committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-12-13 23:50:12 +0400 |
commit | bbfc9c9ee5de680320aeae2f8bd981ebe7af6861 (patch) | |
tree | 0b1f05721de43ea51d17034e6383447f892dabf7 /silk/NSQ.c | |
parent | bf75c8ec4d0dded188bc7793de6da56c7ff0be1c (diff) |
Improves the accuracy such that it matches a float decoder much better
Diffstat (limited to 'silk/NSQ.c')
-rw-r--r-- | silk/NSQ.c | 59 |
1 files changed, 34 insertions, 25 deletions
@@ -34,7 +34,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. static inline void silk_nsq_scale_states( const silk_encoder_state *psEncC, /* I Encoder State */ silk_nsq_state *NSQ, /* I/O NSQ state */ - const opus_int32 x_Q10[], /* I input in Q0 */ + const opus_int32 x_Q3[], /* I input in Q3 */ opus_int32 x_sc_Q10[], /* O input scaled with 1/Gain */ const opus_int16 sLTP[], /* I re-whitened LTP state in Q0 */ opus_int32 sLTP_Q15[], /* O LTP state matching scaled input */ @@ -71,7 +71,7 @@ void silk_NSQ( const silk_encoder_state *psEncC, /* I/O Encoder State */ silk_nsq_state *NSQ, /* I/O NSQ state */ SideInfoIndices *psIndices, /* I/O Quantization Indices */ - const opus_int32 x_Q10[], /* I Prefiltered input signal */ + const opus_int32 x_Q3[], /* I Prefiltered input signal */ opus_int8 pulses[], /* O Quantized pulse signal */ const opus_int16 PredCoef_Q12[ 2 * MAX_LPC_ORDER ], /* I Short term prediction coefs */ const opus_int16 LTPCoef_Q14[ LTP_ORDER * MAX_NB_SUBFR ], /* I Long term prediction coefs */ @@ -99,7 +99,7 @@ void silk_NSQ( /* Set unvoiced lag to the previous one, overwrite later for voiced */ lag = NSQ->lagPrev; - silk_assert( NSQ->prev_inv_gain_Q16 != 0 ); + silk_assert( NSQ->prev_inv_gain_Q31 != 0 ); offset_Q10 = silk_Quantization_Offsets_Q10[ psIndices->signalType >> 1 ][ psIndices->quantOffsetType ]; @@ -142,13 +142,13 @@ void silk_NSQ( } } - silk_nsq_scale_states( psEncC, NSQ, x_Q10, x_sc_Q10, sLTP, sLTP_Q15, k, LTP_scale_Q14, Gains_Q16, pitchL, psIndices->signalType ); + silk_nsq_scale_states( psEncC, NSQ, x_Q3, x_sc_Q10, sLTP, sLTP_Q15, k, LTP_scale_Q14, Gains_Q16, pitchL, psIndices->signalType ); silk_noise_shape_quantizer( NSQ, psIndices->signalType, x_sc_Q10, pulses, pxq, sLTP_Q15, A_Q12, B_Q14, AR_shp_Q13, lag, HarmShapeFIRPacked_Q14, Tilt_Q14[ k ], LF_shp_Q14[ k ], Gains_Q16[ k ], Lambda_Q10, offset_Q10, psEncC->subfr_length, psEncC->shapingLPCOrder, psEncC->predictLPCOrder ); - x_Q10 += psEncC->subfr_length; + x_Q3 += psEncC->subfr_length; pulses += psEncC->subfr_length; pxq += psEncC->subfr_length; } @@ -157,6 +157,7 @@ void silk_NSQ( NSQ->lagPrev = pitchL[ psEncC->nb_subfr - 1 ]; /* Save quantized speech and noise shaping signals */ + /* DEBUG_STORE_DATA( enc.pcm, &NSQ->xq[ psEncC->ltp_mem_length ], psEncC->frame_length * sizeof( opus_int16 ) ) */ silk_memmove( NSQ->xq, &NSQ->xq[ psEncC->frame_length ], psEncC->ltp_mem_length * sizeof( opus_int16 ) ); silk_memmove( NSQ->sLTP_shp_Q10, &NSQ->sLTP_shp_Q10[ psEncC->frame_length ], psEncC->ltp_mem_length * sizeof( opus_int32 ) ); } @@ -208,7 +209,9 @@ static inline void silk_noise_shape_quantizer( /* Short-term prediction */ silk_assert( predictLPCOrder == 10 || predictLPCOrder == 16 ); - LPC_pred_Q10 = silk_SMULWB( psLPC_Q14[ 0 ], a_Q12[ 0 ] ); + /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ + LPC_pred_Q10 = silk_RSHIFT( predictLPCOrder, 1 ); + LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psLPC_Q14[ 0 ], a_Q12[ 0 ] ); LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -1 ], a_Q12[ 1 ] ); LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -2 ], a_Q12[ 2 ] ); LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, psLPC_Q14[ -3 ], a_Q12[ 3 ] ); @@ -230,7 +233,9 @@ static inline void silk_noise_shape_quantizer( /* Long-term prediction */ if( signalType == TYPE_VOICED ) { /* 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 ] ); @@ -273,7 +278,7 @@ static inline void silk_noise_shape_quantizer( n_LTP_Q14 = silk_LSHIFT( n_LTP_Q14, 6 ); shp_lag_ptr++; - tmp1 = silk_SUB32( LTP_pred_Q13 << 1, n_LTP_Q14 ); /* Add Q14 stuff */ + tmp1 = silk_SUB32( silk_LSHIFT32( LTP_pred_Q13, 1 ), n_LTP_Q14 ); /* Add Q14 stuff */ tmp1 = silk_RSHIFT( tmp1, 4 ); /* convert to Q10 */ tmp1 = silk_ADD32( tmp1, LPC_pred_Q10 ); /* add Q10 stuff */ tmp1 = silk_SUB32( tmp1, n_AR_Q10 ); /* subtract Q10 stuff */ @@ -337,7 +342,6 @@ static inline void silk_noise_shape_quantizer( /* Scale XQ back to normal level before saving */ xq[ i ] = ( opus_int16 )silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( xq_Q10, Gain_Q16 ), 10 ) ); - /* DEBUG_STORE_DATA( enc.pcm, &xq[i], sizeof( opus_int16 ) ) */ /* Update states */ psLPC_Q14++; *psLPC_Q14 = silk_LSHIFT( xq_Q10, 4 ); @@ -360,7 +364,7 @@ static inline void silk_noise_shape_quantizer( static inline void silk_nsq_scale_states( const silk_encoder_state *psEncC, /* I Encoder State */ silk_nsq_state *NSQ, /* I/O NSQ state */ - const opus_int32 x_Q10[], /* I input in Q0 */ + const opus_int32 x_Q3[], /* I input in Q3 */ opus_int32 x_sc_Q10[], /* O input scaled with 1/Gain */ const opus_int16 sLTP[], /* I re-whitened LTP state in Q0 */ opus_int32 sLTP_Q15[], /* O LTP state matching scaled input */ @@ -372,14 +376,30 @@ static inline void silk_nsq_scale_states( ) { opus_int i, lag; - opus_int32 inv_gain_Q16, gain_adj_Q16, inv_gain_Q31; + opus_int32 gain_adj_Q16, inv_gain_Q31, inv_gain_Q23; - inv_gain_Q16 = silk_INVERSE32_varQ( silk_max( Gains_Q16[ subfr ], 1 ), 32 ); + inv_gain_Q31 = silk_INVERSE32_varQ( silk_max( Gains_Q16[ subfr ], 1 ), 47 ); lag = pitchL[ subfr ]; + /* Calculate gain adjustment factor */ + if( inv_gain_Q31 != NSQ->prev_inv_gain_Q31 ) { + gain_adj_Q16 = silk_DIV32_varQ( inv_gain_Q31, NSQ->prev_inv_gain_Q31, 16 ); + } else { + gain_adj_Q16 = 1 << 16; + } + + /* Scale input */ + inv_gain_Q23 = silk_RSHIFT_ROUND( inv_gain_Q31, 8 ); + for( i = 0; i < psEncC->subfr_length; i++ ) { + x_sc_Q10[ i ] = silk_SMULWW( x_Q3[ i ], inv_gain_Q23 ); + } + + /* Save inverse gain */ + silk_assert( inv_gain_Q31 != 0 ); + NSQ->prev_inv_gain_Q31 = inv_gain_Q31; + /* After rewhitening the LTP state is un-scaled, so scale with inv_gain_Q16 */ if( NSQ->rewhite_flag ) { - inv_gain_Q31 = silk_LSHIFT( inv_gain_Q16, 15 ); if( subfr == 0 ) { /* Do LTP downscaling */ inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, LTP_scale_Q14 ), 2 ); @@ -391,9 +411,7 @@ static inline void silk_nsq_scale_states( } /* Adjust for changing gain */ - if( inv_gain_Q16 != NSQ->prev_inv_gain_Q16 ) { - gain_adj_Q16 = silk_DIV32_varQ( inv_gain_Q16, NSQ->prev_inv_gain_Q16, 16 ); - + if( gain_adj_Q16 != 1 << 16 ) { /* Scale long-term shaping state */ for( i = NSQ->sLTP_shp_buf_idx - psEncC->ltp_mem_length; i < NSQ->sLTP_shp_buf_idx; i++ ) { NSQ->sLTP_shp_Q10[ i ] = silk_SMULWW( gain_adj_Q16, NSQ->sLTP_shp_Q10[ i ] ); @@ -416,13 +434,4 @@ static inline void silk_nsq_scale_states( NSQ->sAR2_Q14[ i ] = silk_SMULWW( gain_adj_Q16, NSQ->sAR2_Q14[ i ] ); } } - - /* Scale input */ - for( i = 0; i < psEncC->subfr_length; i++ ) { - x_sc_Q10[ i ] = silk_SMULWW( x_Q10[ i ], inv_gain_Q16 ); - } - - /* Save inv_gain */ - silk_assert( inv_gain_Q16 != 0 ); - NSQ->prev_inv_gain_Q16 = inv_gain_Q16; } |