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Tuning the surround masking

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We're now a bit more conservative and only take into account the bands
that are being codec. Also weighting the rate saving by the band width.
This commit is contained in:
Jean-Marc Valin 2013-09-12 03:05:43 -04:00
parent 54bddf0f1a
commit 039e9ab155
1 changed files with 17 additions and 9 deletions
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26
celt/celt_encoder.c
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@ -1535,27 +1535,35 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
for(i=0;i<st->end;i++)
surround_dynalloc[i] = 0;
/* This computes how much masking takes place between surround channels */
if (st->energy_mask&&!st->lfe)
if (st->start==0&&st->energy_mask&&!st->lfe)
{
int mask_end;
opus_val32 mask_avg=0;
opus_val32 diff=0;
int count=0;
mask_end = st->lastCodedBands;
for (c=0;c<C;c++)
{
for(i=0;i<st->end;i++)
for(i=0;i<mask_end;i++)
{
mask_avg += st->energy_mask[nbEBands*c+i];
diff += st->energy_mask[i+c*nbEBands]*(opus_int32)(1+2*i-st->end);
mask_avg += st->energy_mask[nbEBands*c+i]*(eBands[i+1]-eBands[i]);
count += (eBands[i+1]-eBands[i]);
diff += st->energy_mask[i+c*nbEBands]*(opus_int32)(1+2*i-mask_end);
}
}
mask_avg = DIV32_16(mask_avg,C*st->end);
mask_avg = DIV32_16(mask_avg,count);
/* Just being conservative here */
mask_avg -= HALF32(HALF32(mask_avg));
mask_avg = MAX16(mask_avg, -QCONST16(2.f, DB_SHIFT));
diff = diff*6/(C*(st->end-1)*(st->end+1)*st->end);
diff = MAX32(MIN32(diff, QCONST32(.05f, DB_SHIFT)), -QCONST32(.05f, DB_SHIFT));
for(i=0;i<st->end;i++)
diff = diff*6/(C*(mask_end-1)*(mask_end+1)*mask_end);
/* Again, being conservative */
diff = HALF32(diff);
diff = MAX32(MIN32(diff, QCONST32(.031f, DB_SHIFT)), -QCONST32(.031f, DB_SHIFT));
for(i=0;i<mask_end;i++)
{
opus_val32 lin;
opus_val16 unmask;
lin = mask_avg + HALF32(diff*(1+2*i-st->end));
lin = mask_avg + HALF32(diff*(1+2*i-mask_end));
if (C==2)
unmask = MAX16(st->energy_mask[i], st->energy_mask[nbEBands+i]) - lin;
else