diff options
author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-10-20 08:39:41 +0400 |
---|---|---|
committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-10-20 08:39:41 +0400 |
commit | 294bfec27b82f879e3c3004d31bb91bcb34014f4 (patch) | |
tree | 94a6332cc1df41ec84b453ef76ee8118b95bfd8f /silk/fixed/encode_frame_FIX.c | |
parent | dbf2ea841e5b022f0b6d15a606dd7288f25c35dd (diff) |
Implements hard CBR for SILK
This is achieved by running the encoding process in a loop and
padding when we don't reach the exact rate. It also implements
VBR-with-cap, which means we no longer need to artificially decrease
the SILK bandwidth when it's close to the cap.
Diffstat (limited to 'silk/fixed/encode_frame_FIX.c')
-rw-r--r-- | silk/fixed/encode_frame_FIX.c | 166 |
1 files changed, 136 insertions, 30 deletions
diff --git a/silk/fixed/encode_frame_FIX.c b/silk/fixed/encode_frame_FIX.c index e351def9..a8633f5a 100644 --- a/silk/fixed/encode_frame_FIX.c +++ b/silk/fixed/encode_frame_FIX.c @@ -79,14 +79,23 @@ opus_int silk_encode_frame_FIX( silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ opus_int32 *pnBytesOut, /* O Number of payload bytes */ ec_enc *psRangeEnc, /* I/O compressor data structure */ - opus_int condCoding /* I The type of conditional coding to use */ + opus_int condCoding, /* I The type of conditional coding to use */ + opus_int maxBits, /* I If > 0: maximum number of output bits */ + opus_int useCBR /* I Flag to force constant-bitrate operation */ ) { silk_encoder_control_FIX sEncCtrl; - opus_int ret = 0; + opus_int i, iter, maxIter, found_upper, found_lower, ret = 0; opus_int16 *x_frame, *res_pitch_frame; opus_int16 xfw[ MAX_FRAME_LENGTH ]; opus_int16 res_pitch[ 2 * MAX_FRAME_LENGTH + LA_PITCH_MAX ]; + ec_enc sRangeEnc_copy, sRangeEnc_copy2; + silk_nsq_state sNSQ_copy, sNSQ_copy2; + opus_int32 seed_copy, nBits, nBits_lower, nBits_upper, gainMult_Q10, gainMult_lower, gainMult_upper; + opus_int16 ec_prevLagIndex_copy; + opus_int ec_prevSignalType_copy; + opus_int8 LastGainIndex_copy2; + opus_uint8 ec_buf_copy[ 512 ]; TIC(ENCODE_FRAME) @@ -151,21 +160,132 @@ TIC(LBRR) silk_LBRR_encode_FIX( psEnc, &sEncCtrl, xfw, condCoding ); TOC(LBRR) - /*****************************************/ - /* Noise shaping quantization */ - /*****************************************/ + /* Loop over quantizer and entroy coding to control bitrate */ + maxIter = 5; + gainMult_Q10 = SILK_FIX_CONST( 1, 10 ); + found_lower = 0; + found_upper = 0; + for( iter = 0; ; iter++ ) { + if( maxBits > 0 && !psEnc->sCmn.prefillFlag ) { + /* Copy part of the input state */ + silk_memcpy( &sRangeEnc_copy, psRangeEnc, sizeof( ec_enc ) ); + silk_memcpy( &sNSQ_copy, &psEnc->sCmn.sNSQ, sizeof( silk_nsq_state ) ); + seed_copy = psEnc->sCmn.indices.Seed; + ec_prevLagIndex_copy = psEnc->sCmn.ec_prevLagIndex; + ec_prevSignalType_copy = psEnc->sCmn.ec_prevSignalType; + } + + /*****************************************/ + /* Noise shaping quantization */ + /*****************************************/ TIC(NSQ) - if( psEnc->sCmn.nStatesDelayedDecision > 1 || psEnc->sCmn.warping_Q16 > 0 ) { - silk_NSQ_del_dec( &psEnc->sCmn, &psEnc->sCmn.sNSQ, &psEnc->sCmn.indices, xfw, psEnc->sCmn.pulses, - sEncCtrl.PredCoef_Q12[ 0 ], sEncCtrl.LTPCoef_Q14, sEncCtrl.AR2_Q13, sEncCtrl.HarmShapeGain_Q14, - sEncCtrl.Tilt_Q14, sEncCtrl.LF_shp_Q14, sEncCtrl.Gains_Q16, sEncCtrl.pitchL, sEncCtrl.Lambda_Q10, sEncCtrl.LTP_scale_Q14 ); - } else { - silk_NSQ( &psEnc->sCmn, &psEnc->sCmn.sNSQ, &psEnc->sCmn.indices, xfw, psEnc->sCmn.pulses, - sEncCtrl.PredCoef_Q12[ 0 ], sEncCtrl.LTPCoef_Q14, sEncCtrl.AR2_Q13, sEncCtrl.HarmShapeGain_Q14, - sEncCtrl.Tilt_Q14, sEncCtrl.LF_shp_Q14, sEncCtrl.Gains_Q16, sEncCtrl.pitchL, sEncCtrl.Lambda_Q10, sEncCtrl.LTP_scale_Q14 ); - } + if( psEnc->sCmn.nStatesDelayedDecision > 1 || psEnc->sCmn.warping_Q16 > 0 ) { + silk_NSQ_del_dec( &psEnc->sCmn, &psEnc->sCmn.sNSQ, &psEnc->sCmn.indices, xfw, psEnc->sCmn.pulses, + sEncCtrl.PredCoef_Q12[ 0 ], sEncCtrl.LTPCoef_Q14, sEncCtrl.AR2_Q13, sEncCtrl.HarmShapeGain_Q14, + sEncCtrl.Tilt_Q14, sEncCtrl.LF_shp_Q14, sEncCtrl.Gains_Q16, sEncCtrl.pitchL, sEncCtrl.Lambda_Q10, sEncCtrl.LTP_scale_Q14 ); + } else { + silk_NSQ( &psEnc->sCmn, &psEnc->sCmn.sNSQ, &psEnc->sCmn.indices, xfw, psEnc->sCmn.pulses, + sEncCtrl.PredCoef_Q12[ 0 ], sEncCtrl.LTPCoef_Q14, sEncCtrl.AR2_Q13, sEncCtrl.HarmShapeGain_Q14, + sEncCtrl.Tilt_Q14, sEncCtrl.LF_shp_Q14, sEncCtrl.Gains_Q16, sEncCtrl.pitchL, sEncCtrl.Lambda_Q10, sEncCtrl.LTP_scale_Q14 ); + } TOC(NSQ) + if( psEnc->sCmn.prefillFlag ) { + break; + } else { + /****************************************/ + /* Encode Parameters */ + /****************************************/ +TIC(ENCODE_PARAMS) + silk_encode_indices( &psEnc->sCmn, psRangeEnc, psEnc->sCmn.nFramesEncoded, 0, condCoding ); +TOC(ENCODE_PARAMS) + + /****************************************/ + /* Encode Excitation Signal */ + /****************************************/ +TIC(ENCODE_PULSES) + silk_encode_pulses( psRangeEnc, psEnc->sCmn.indices.signalType, psEnc->sCmn.indices.quantOffsetType, + psEnc->sCmn.pulses, psEnc->sCmn.frame_length ); +TOC(ENCODE_PULSES) + + } + + nBits = ec_tell( psRangeEnc ); + + if( maxBits == 0 || ( useCBR == 0 && iter == 0 && nBits <= maxBits ) ) { + break; + } + + if( iter == maxIter ) { + if( nBits > maxBits && found_lower ) { + /* Restore output state from earlier iteration that did meet the bitrate budget */ + silk_memcpy( psRangeEnc, &sRangeEnc_copy2, sizeof( ec_enc ) ); + silk_memcpy( psRangeEnc->buf, ec_buf_copy, sRangeEnc_copy2.offs ); + silk_memcpy( &psEnc->sCmn.sNSQ, &sNSQ_copy2, sizeof( silk_nsq_state ) ); + psEnc->sShape.LastGainIndex = LastGainIndex_copy2; + } + break; + } + + if( nBits > maxBits ) { + found_upper = 1; + nBits_upper = nBits; + gainMult_upper = gainMult_Q10; + if( found_lower == 0 && iter >= 2 ) { + /* Adjust the quantizer's rate/distortion tradeoff */ + sEncCtrl.Lambda_Q10 = silk_ADD_RSHIFT32( sEncCtrl.Lambda_Q10, sEncCtrl.Lambda_Q10, 1 ); + } + } else if( nBits < maxBits - 5 ) { + found_lower = 1; + nBits_lower = nBits; + gainMult_lower = gainMult_Q10; + /* Copy part of the output state */ + silk_memcpy( &sRangeEnc_copy2, psRangeEnc, sizeof( ec_enc ) ); + silk_memcpy( ec_buf_copy, psRangeEnc->buf, psRangeEnc->offs ); + silk_memcpy( &sNSQ_copy2, &psEnc->sCmn.sNSQ, sizeof( silk_nsq_state ) ); + LastGainIndex_copy2 = psEnc->sShape.LastGainIndex; + } else { + /* Within 5 bits of budget: close enough */ + break; + } + + if( ( found_lower & found_upper ) == 0 ) { + /* Adjust gain according to high-rate rate/distortion curve */ + opus_int32 gain_factor_Q16;
+ gain_factor_Q16 = silk_log2lin( silk_LSHIFT( nBits - maxBits, 7 ) / psEnc->sCmn.frame_length + SILK_FIX_CONST( 16, 7 ) );
+ if( nBits > maxBits ) { + gain_factor_Q16 = silk_max_32( gain_factor_Q16, SILK_FIX_CONST( 1.3, 16 ) ); + } + gainMult_Q10 = silk_SMULWW( gainMult_Q10, gain_factor_Q16 );
+ } else { + /* Adjust gain by interpolating */ + gainMult_Q10 = gainMult_lower + silk_DIV32_16( silk_MUL( gainMult_upper - gainMult_lower, maxBits - nBits_lower ), nBits_upper - nBits_lower ); + /* New gain multplier must be between 25% and 75% of old range (note that gainMult_upper < gainMult_lower) */ + if( gainMult_Q10 > gainMult_lower + silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 ) ) { + gainMult_Q10 = gainMult_lower + silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 ); + } else + if( gainMult_Q10 < gainMult_upper - silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 ) ) { + gainMult_Q10 = gainMult_upper - silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 ); + } + } + + for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) { + sEncCtrl.Gains_Q16[ i ] = silk_LSHIFT_SAT32( silk_SMULWW( sEncCtrl.GainsUnq_Q16[ i ], gainMult_Q10 ), 6 ); + } + psEnc->sShape.LastGainIndex = sEncCtrl.lastGainIndexPrev; + + /* Noise shaping quantization */ + silk_gains_quant( psEnc->sCmn.indices.GainsIndices, sEncCtrl.Gains_Q16, + &psEnc->sShape.LastGainIndex, condCoding == CODE_CONDITIONALLY, psEnc->sCmn.nb_subfr ); + + /* Restore part of the input state */ + silk_memcpy( psRangeEnc, &sRangeEnc_copy, sizeof( ec_enc ) ); + silk_memcpy( &psEnc->sCmn.sNSQ, &sNSQ_copy, sizeof( silk_nsq_state ) ); + psEnc->sCmn.indices.Seed = seed_copy; + psEnc->sCmn.ec_prevLagIndex = ec_prevLagIndex_copy; + psEnc->sCmn.ec_prevSignalType = ec_prevSignalType_copy; + } + /* Update input buffer */ silk_memmove( psEnc->x_buf, &psEnc->x_buf[ psEnc->sCmn.frame_length ], ( psEnc->sCmn.ltp_mem_length + LA_SHAPE_MS * psEnc->sCmn.fs_kHz ) * sizeof( opus_int16 ) ); @@ -182,27 +302,13 @@ TOC(NSQ) } /****************************************/ - /* Encode Parameters */ - /****************************************/ -TIC(ENCODE_PARAMS) - silk_encode_indices( &psEnc->sCmn, psRangeEnc, psEnc->sCmn.nFramesEncoded, 0, condCoding ); -TOC(ENCODE_PARAMS) - - /****************************************/ - /* Encode Excitation Signal */ - /****************************************/ -TIC(ENCODE_PULSES) - silk_encode_pulses( psRangeEnc, psEnc->sCmn.indices.signalType, psEnc->sCmn.indices.quantOffsetType, - psEnc->sCmn.pulses, psEnc->sCmn.frame_length ); -TOC(ENCODE_PULSES) - - /****************************************/ /* Finalize payload */ /****************************************/ psEnc->sCmn.first_frame_after_reset = 0; /* Payload size */ *pnBytesOut = silk_RSHIFT( ec_tell( psRangeEnc ) + 7, 3 ); -TOC(ENCODE_FRAME) + + TOC(ENCODE_FRAME) #ifdef SAVE_ALL_INTERNAL_DATA { |