diff --git a/silk/control_SNR.c b/silk/control_SNR.c index f04e69fc..cee87eb0 100644 --- a/silk/control_SNR.c +++ b/silk/control_SNR.c @@ -70,11 +70,6 @@ opus_int silk_control_SNR( break; } } - - /* Reduce coding quality whenever LBRR is enabled, to free up some bits */ - if( psEncC->LBRR_enabled ) { - psEncC->SNR_dB_Q7 = silk_SMLABB( psEncC->SNR_dB_Q7, 12 - psEncC->LBRR_GainIncreases, SILK_FIX_CONST( -0.25, 7 ) ); - } } return ret; diff --git a/silk/control_codec.c b/silk/control_codec.c index 1f674bdd..044eea3f 100644 --- a/silk/control_codec.c +++ b/silk/control_codec.c @@ -397,9 +397,10 @@ static OPUS_INLINE opus_int silk_setup_LBRR( const opus_int32 TargetRate_bps /* I */ ) { - opus_int ret = SILK_NO_ERROR; + opus_int LBRR_in_previous_packet, ret = SILK_NO_ERROR; opus_int32 LBRR_rate_thres_bps; + LBRR_in_previous_packet = psEncC->LBRR_enabled; psEncC->LBRR_enabled = 0; if( psEncC->useInBandFEC && psEncC->PacketLoss_perc > 0 ) { if( psEncC->fs_kHz == 8 ) { @@ -413,8 +414,13 @@ static OPUS_INLINE opus_int silk_setup_LBRR( if( TargetRate_bps > LBRR_rate_thres_bps ) { /* Set gain increase for coding LBRR excitation */ + if( LBRR_in_previous_packet == 0 ) { + /* Previous packet did not have LBRR, and was therefore coded at a higher bitrate */ + psEncC->LBRR_GainIncreases = 7; + } else { + psEncC->LBRR_GainIncreases = silk_max_int( 7 - silk_SMULWB( (opus_int32)psEncC->PacketLoss_perc, SILK_FIX_CONST( 0.4, 16 ) ), 2 ); + } psEncC->LBRR_enabled = 1; - psEncC->LBRR_GainIncreases = silk_max_int( 7 - silk_SMULWB( (opus_int32)psEncC->PacketLoss_perc, SILK_FIX_CONST( 0.4, 16 ) ), 2 ); } } diff --git a/silk/enc_API.c b/silk/enc_API.c index f1993ada..f8060286 100644 --- a/silk/enc_API.c +++ b/silk/enc_API.c @@ -376,26 +376,33 @@ opus_int silk_Encode( /* O Returns error co for( n = 0; n < encControl->nChannelsInternal; n++ ) { silk_memset( psEnc->state_Fxx[ n ].sCmn.LBRR_flags, 0, sizeof( psEnc->state_Fxx[ n ].sCmn.LBRR_flags ) ); } + + psEnc->nBitsUsedLBRR = ec_tell( psRangeEnc ); } silk_HP_variable_cutoff( psEnc->state_Fxx ); /* Total target bits for packet */ nBits = silk_DIV32_16( silk_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 ); - /* Subtract half of the bits already used */ + /* Subtract bits used for LBRR */ if( !prefillFlag ) { - nBits -= ec_tell( psRangeEnc ) >> 1; + nBits -= psEnc->nBitsUsedLBRR; } /* Divide by number of uncoded frames left in packet */ - nBits = silk_DIV32_16( nBits, psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket - psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ); + nBits = silk_DIV32_16( nBits, psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket ); /* Convert to bits/second */ if( encControl->payloadSize_ms == 10 ) { TargetRate_bps = silk_SMULBB( nBits, 100 ); } else { TargetRate_bps = silk_SMULBB( nBits, 50 ); } - /* Subtract fraction of bits in excess of target in previous packets */ + /* Subtract fraction of bits in excess of target in previous frames and packets */ TargetRate_bps -= silk_DIV32_16( silk_MUL( psEnc->nBitsExceeded, 1000 ), BITRESERVOIR_DECAY_TIME_MS ); + if( !prefillFlag && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded > 0 ) { + /* Compare actual vs target bits so far in this packet */ + opus_int32 bitsBalance = ec_tell( psRangeEnc ) - psEnc->nBitsUsedLBRR - nBits * psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded; + TargetRate_bps -= silk_DIV32_16( silk_MUL( bitsBalance, 1000 ), BITRESERVOIR_DECAY_TIME_MS ); + } /* Never exceed input bitrate */ TargetRate_bps = silk_LIMIT( TargetRate_bps, encControl->bitRate, 5000 ); diff --git a/silk/fixed/structs_FIX.h b/silk/fixed/structs_FIX.h index 244b4793..3294b251 100644 --- a/silk/fixed/structs_FIX.h +++ b/silk/fixed/structs_FIX.h @@ -116,6 +116,7 @@ typedef struct { typedef struct { silk_encoder_state_FIX state_Fxx[ ENCODER_NUM_CHANNELS ]; stereo_enc_state sStereo; + opus_int32 nBitsUsedLBRR; opus_int32 nBitsExceeded; opus_int nChannelsAPI; opus_int nChannelsInternal; diff --git a/silk/float/structs_FLP.h b/silk/float/structs_FLP.h index bb529e71..14d647ce 100644 --- a/silk/float/structs_FLP.h +++ b/silk/float/structs_FLP.h @@ -115,6 +115,7 @@ typedef struct { typedef struct { silk_encoder_state_FLP state_Fxx[ ENCODER_NUM_CHANNELS ]; stereo_enc_state sStereo; + opus_int32 nBitsUsedLBRR; opus_int32 nBitsExceeded; opus_int nChannelsAPI; opus_int nChannelsInternal;