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Limits how fast the CBR gain multiplier can increase

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This fixes an overflow that was caused by having a huge gain
This commit is contained in:
Jean-Marc Valin 2011-10-21 11:05:50 -04:00
parent 1fad3048af
commit 44a030deed
1 changed files with 14 additions and 12 deletions
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26
silk/float/encode_frame_FLP.c
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@ -94,7 +94,8 @@ opus_int silk_encode_frame_FLP(
silk_float 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_int32 seed_copy, nBits, nBits_lower, nBits_upper, gainMult_lower, gainMult_upper;
opus_int16 gainMult_Q8;
opus_int16 ec_prevLagIndex_copy;
opus_int ec_prevSignalType_copy;
opus_int8 LastGainIndex_copy2;
@ -181,7 +182,7 @@ TOC(NSQ)
} else {
/* Loop over quantizer and entroy coding to control bitrate */
maxIter = 5;
gainMult_Q10 = SILK_FIX_CONST( 1, 10 );
gainMult_Q8 = SILK_FIX_CONST( 1, 8 );
found_lower = 0;
found_upper = 0;
for( iter = 0; ; iter++ ) {
@ -234,7 +235,7 @@ TOC(ENCODE_PULSES)
if( nBits > maxBits ) {
found_upper = 1;
nBits_upper = nBits;
gainMult_upper = gainMult_Q10;
gainMult_upper = gainMult_Q8;
if( found_lower == 0 && iter >= 3 ) {
/* Adjust the quantizer's rate/distortion tradeoff */
sEncCtrl.Lambda *= 1.5f;
@ -242,7 +243,7 @@ TOC(ENCODE_PULSES)
} else if( nBits < maxBits - 5 ) {
found_lower = 1;
nBits_lower = nBits;
gainMult_lower = gainMult_Q10;
gainMult_lower = gainMult_Q8;
/* Copy part of the output state */
silk_memcpy( &sRangeEnc_copy2, psRangeEnc, sizeof( ec_enc ) );
silk_memcpy( ec_buf_copy, psRangeEnc->buf, psRangeEnc->offs );
@ -256,25 +257,26 @@ TOC(ENCODE_PULSES)
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 ) );
gain_factor_Q16 = silk_log2lin( silk_LSHIFT( nBits - maxBits, 7 ) / psEnc->sCmn.frame_length + SILK_FIX_CONST( 16, 7 ) );
gain_factor_Q16 = silk_min_32(gain_factor_Q16, SILK_FIX_CONST( 2, 16 ) );
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 );
gainMult_Q8 = silk_SMULWB( gain_factor_Q16, gainMult_Q8 );
} else {
/* Adjust gain by interpolating */
gainMult_Q10 = gainMult_lower + ( ( gainMult_upper - gainMult_lower ) * ( maxBits - nBits_lower ) ) / ( nBits_upper - nBits_lower );
gainMult_Q8 = gainMult_lower + ( ( 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 );
if( gainMult_Q8 > gainMult_lower + silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 ) ) {
gainMult_Q8 = 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 );
if( gainMult_Q8 < gainMult_upper - silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 ) ) {
gainMult_Q8 = gainMult_upper - silk_RSHIFT32( gainMult_upper - gainMult_lower, 2 );
}
}
for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
pGains_Q16[ i ] = silk_LSHIFT_SAT32( silk_SMULWW( sEncCtrl.GainsUnq_Q16[ i ], gainMult_Q10 ), 6 );
pGains_Q16[ i ] = silk_LSHIFT_SAT32( silk_SMULWB( sEncCtrl.GainsUnq_Q16[ i ], gainMult_Q8 ), 8 );
}
psEnc->sShape.LastGainIndex = sEncCtrl.lastGainIndexPrev;