ref: 97a48473acee2d3c2ec2f5a619dad6078874af23
parent: 26dbb8e782ca2fc2752e84ac1015dd90d44d4941
author: Jean-Marc Valin <[email protected]>
date: Thu Sep 13 21:25:05 EDT 2012
Makes dynalloc more conservative for CBR and CVBR
--- a/celt/celt.c
+++ b/celt/celt.c
@@ -1527,10 +1527,17 @@
follower[i] = MAX16(0, bandLogE[i]-follower[i]);
}
}
+ /* For non-transient CBR/CVBR frames, halve the dynalloc contribution */
+ if ((!st->vbr || st->constrained_vbr)&&!isTransient)
+ {+ for (i=st->start;i<st->end;i++)
+ follower[i] = HALF16(follower[i]);
+ }
for (i=st->start;i<st->end;i++)
{int width;
int boost;
+ int boost_bits;
if (i<8)
follower[i] *= 2;
@@ -1537,19 +1544,30 @@
if (i>=12)
follower[i] = HALF16(follower[i]);
follower[i] = MIN16(follower[i], QCONST16(4, DB_SHIFT));
+
+ /* FIXME: Adaptively reduce follower at low rate or for cbr/cvbr */
width = C*(st->mode->eBands[i+1]-st->mode->eBands[i])<<LM;
if (width<6)
{boost = SHR32(EXTEND32(follower[i]),DB_SHIFT);
- tot_boost += boost*width<<BITRES;
+ boost_bits = boost*width<<BITRES;
} else if (width > 48) {boost = SHR32(EXTEND32(follower[i])*8,DB_SHIFT);
- tot_boost += (boost*width<<BITRES)/8;
+ boost_bits = (boost*width<<BITRES)/8;
} else {boost = SHR32(EXTEND32(follower[i])*width/6,DB_SHIFT);
- tot_boost += boost*6<<BITRES;
+ boost_bits = boost*6<<BITRES;
}
- offsets[i] = boost;
+ /* For CBR and non-transient CVBR frames, limit dynalloc to 1/4 of the bits */
+ if ((!st->vbr || (st->constrained_vbr&&!isTransient))
+ && (tot_boost+boost_bits)>>BITRES>>3 > effectiveBytes/4)
+ {+ offsets[i] = 0;
+ break;
+ } else {+ offsets[i] = boost;
+ tot_boost += boost_bits;
+ }
}
}
dynalloc_logp = 6;