ref: 9cf62baafc02e53ffb86e498ac3dc0e6b1f8e03e
parent: 27aea5c902ddab2bae21a3f03ae9466db690529c
author: Jean-Marc Valin <[email protected]>
date: Mon Nov 7 19:02:25 EST 2011
Implements a better transient metric for VBR
--- a/celt/celt.c
+++ b/celt/celt.c
@@ -292,7 +292,7 @@
}
static int transient_analysis(const opus_val32 * restrict in, int len, int C,
- int overlap)
+ int overlap, opus_val16 *tf_estimate)
{int i;
VARDECL(opus_val16, tmp);
@@ -300,6 +300,8 @@
int is_transient = 0;
int block;
int N;
+ opus_val16 maxbin;
+ opus_val32 L1, L2, tf_tmp;
VARDECL(opus_val16, bins);
SAVE_STACK;
ALLOC(tmp, len, opus_val16);
@@ -335,6 +337,7 @@
for (i=0;i<12;i++)
tmp[i] = 0;
+ maxbin=0;
for (i=0;i<N;i++)
{int j;
@@ -342,13 +345,20 @@
for (j=0;j<block;j++)
max_abs = MAX16(max_abs, ABS16(tmp[i*block+j]));
bins[i] = max_abs;
+ maxbin = MAX16(maxbin, bins[i]);
}
+ L1=0;
+ L2=0;
for (i=0;i<N;i++)
{int j;
int conseq=0;
opus_val16 t1, t2, t3;
+ opus_val16 tmp_bin;
+ tmp_bin = bins[i]+MULT16_16_Q15(QCONST16(.05f,15),maxbin);
+ L1 += EXTEND32(tmp_bin);
+ L2 += SHR32(MULT16_16(tmp_bin, tmp_bin), 4);
t1 = MULT16_16_Q15(QCONST16(.15f, 15), bins[i]);
t2 = MULT16_16_Q15(QCONST16(.4f, 15), bins[i]);
t3 = MULT16_16_Q15(QCONST16(.15f, 15), bins[i]);
@@ -374,6 +384,9 @@
if (conseq>=7)
is_transient=1;
}
+ /* sqrt(L2*N)/L1 */
+ tf_tmp = SHL32(DIV32( SHL32(EXTEND32(celt_sqrt(SHR16(L2,4) * N)), 14), ADD32(EPSILON, L1)), 4);
+ *tf_estimate = MAX16(QCONST16(1.f, 14), EXTRACT16(MIN16(QCONST32(1.99, 14), tf_tmp)));
RESTORE_STACK;
#ifdef FUZZING
is_transient = rand()&0x1;
@@ -917,6 +930,7 @@
int anti_collapse_rsv;
int anti_collapse_on=0;
int silence=0;
+ opus_val16 tf_estimate;
ALLOC_STACK;
if (nbCompressedBytes<2 || pcm==NULL)
@@ -1215,7 +1229,7 @@
if (st->complexity > 1)
{isTransient = transient_analysis(in, N+st->overlap, CC,
- st->overlap);
+ st->overlap, &tf_estimate);
if (isTransient)
shortBlocks = M;
}
@@ -1382,15 +1396,11 @@
if (st->constrained_vbr)
target += (st->vbr_offset>>lm_diff);
- /* Shortblocks get a large boost in bitrate, but since they
- are uncommon long blocks are not greatly affected */
- if (shortBlocks || tf_sum < -2*(st->end-st->start))
- target = 7*target/4;
- else if (tf_sum < -(st->end-st->start))
- target = 3*target/2;
- else if (M > 1)
- target-=(target+14)/28;
-
+#ifdef FIXED_POINT
+ target = SHL32(MULT16_32_Q15(target, SUB16(tf_estimate, QCONST16(0.05, 14))),1);
+#else
+ target *= tf_estimate-.05;
+#endif
/* The current offset is removed from the target and the space used
so far is added*/
target=target+tell;