Adding some hysteresis on the folding threshold frequency
This adds some side-information that can be used to change the
threshold freq arbitrarily.
diff --git a/libcelt/celt.c b/libcelt/celt.c
index 0dd58c5..d6bb14b 100644
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -80,6 +80,7 @@
int fold_decision;
int delayedIntra;
int tonal_average;
+ int lastCodedBands;
int prefilter_period;
celt_word16 prefilter_gain;
@@ -740,6 +741,7 @@
int intensity=0;
int dual_stereo=0;
int effectiveBytes;
+ int skip;
SAVE_STACK;
if (nbCompressedBytes<0 || pcm==NULL)
@@ -1103,8 +1105,15 @@
ALLOC(pulses, st->mode->nbEBands, int);
ALLOC(fine_priority, st->mode->nbEBands, int);
- bits = nbCompressedBytes*8 - ec_enc_tell(enc, 0) - 1;
- codedBands = compute_allocation(st->mode, st->start, st->end, offsets, alloc_trim, bits, pulses, fine_quant, fine_priority, C, LM);
+ /* bits = packet size - where we are - safety - skip signalling */
+ bits = nbCompressedBytes*8 - ec_enc_tell(enc, 0) - 1 - (1<<BITRES);
+ skip=-1;
+ codedBands = compute_allocation(st->mode, st->start, st->end, offsets,
+ alloc_trim, bits, pulses, fine_quant, fine_priority, C, LM, &skip, st->lastCodedBands);
+ st->lastCodedBands = codedBands;
+ for (i=0;i<skip;i++)
+ ec_enc_bit_prob(enc, 0, 32768);
+ ec_enc_bit_prob(enc, 1, 32768);
quant_fine_energy(st->mode, st->start, st->end, bandE, oldBandE, error, fine_quant, enc, C);
@@ -1692,6 +1701,7 @@
celt_word16 postfilter_gain;
int intensity=0;
int dual_stereo=0;
+ int skip;
SAVE_STACK;
if (pcm==NULL)
@@ -1825,8 +1835,19 @@
intensity = ec_dec_uint(dec, 1+st->end-st->start);
}
- bits = len*8 - ec_dec_tell(dec, 0) - 1;
- codedBands = compute_allocation(st->mode, st->start, st->end, offsets, alloc_trim, bits, pulses, fine_quant, fine_priority, C, LM);
+ bits = len*8 - ec_dec_tell(dec, 0) - 1 - (1<<BITRES);
+ skip=0;
+ while (ec_dec_bit_prob(dec, 32768)==0)
+ {
+ skip++;
+ if (skip>21)
+ {
+ dec->error = 1;
+ break;
+ }
+ }
+ codedBands = compute_allocation(st->mode, st->start, st->end, offsets,
+ alloc_trim, bits, pulses, fine_quant, fine_priority, C, LM, &skip, 0);
unquant_fine_energy(st->mode, st->start, st->end, bandE, oldBandE, fine_quant, dec, C);
diff --git a/libcelt/rate.c b/libcelt/rate.c
index bdf34d5..301698b 100644
--- a/libcelt/rate.c
+++ b/libcelt/rate.c
@@ -142,7 +142,7 @@
static inline int interp_bits2pulses(const CELTMode *m, int start, int end,
int *bits1, int *bits2, const int *thresh, int total, int *bits,
- int *ebits, int *fine_priority, int len, int _C, int LM)
+ int *ebits, int *fine_priority, int len, int _C, int LM, int *skip, int prev)
{
int psum;
int lo, hi;
@@ -192,6 +192,25 @@
psum += bits[j];
}
codedBands++;
+ if (*skip==-1)
+ {
+ *skip=0;
+ for (j=codedBands-1;j>=0;j--)
+ {
+ if ((bits[j] > (7*(m->eBands[j+1]-m->eBands[j])<<LM<<BITRES)>>4 && j<prev)
+ || (bits[j] > (9*(m->eBands[j+1]-m->eBands[j])<<LM<<BITRES)>>4))
+ break;
+ else
+ (*skip)++;
+ }
+ *skip = IMIN(*skip, codedBands-start-1);
+ }
+ for (i=0;i<*skip;i++)
+ {
+ psum = psum - bits[codedBands-1] + ((C+1)<<BITRES);
+ bits[codedBands-1] = C<<BITRES;
+ codedBands--;
+ }
/* Allocate the remaining bits */
if (codedBands) {
int left, perband;
@@ -267,7 +286,7 @@
}
int compute_allocation(const CELTMode *m, int start, int end, int *offsets, int alloc_trim,
- int total, int *pulses, int *ebits, int *fine_priority, int _C, int LM)
+ int total, int *pulses, int *ebits, int *fine_priority, int _C, int LM, int *skip, int prev)
{
int lo, hi, len, j;
const int C = CHANNELS(_C);
@@ -286,7 +305,7 @@
/* Below this threshold, we don't allocate any PVQ bits */
for (j=start;j<end;j++)
- thresh[j] = (4*(m->eBands[j+1]-m->eBands[j])<<LM<<BITRES)>>3;
+ thresh[j] = ((C+1)<<BITRES) + (3*(m->eBands[j+1]-m->eBands[j])<<LM<<BITRES)>>4;
/* Tilt of the allocation curve */
for (j=start;j<end;j++)
trim_offset[j] = C*(m->eBands[j+1]-m->eBands[j])*(alloc_trim-5-LM)*(m->nbEBands-j-1)
@@ -334,7 +353,7 @@
bits1[j] += offsets[j];
}
codedBands = interp_bits2pulses(m, start, end, bits1, bits2, thresh,
- total, pulses, ebits, fine_priority, len, C, LM);
+ total, pulses, ebits, fine_priority, len, C, LM, skip, prev);
RESTORE_STACK;
return codedBands;
}
diff --git a/libcelt/rate.h b/libcelt/rate.h
index 0a53649..c0089e0 100644
--- a/libcelt/rate.h
+++ b/libcelt/rate.h
@@ -103,7 +103,7 @@
@return Total number of bits allocated
*/
int compute_allocation(const CELTMode *m, int start, int end, int *offsets, int alloc_trim,
- int total, int *pulses, int *ebits, int *fine_priority, int _C, int LM);
+ int total, int *pulses, int *ebits, int *fine_priority, int _C, int LM, int *skip, int prev);
#endif