ref: 8cc945c53af7fbc42864d76550e429583f6e33b5
parent: 524623899c7c03cd116d6782315ab29f9a1dab2b
author: Jean-Marc Valin <[email protected]>
date: Sat May 29 04:07:18 EDT 2010
Cleaning up VBR to be frame-size independent
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -102,7 +102,7 @@
celt_int32 vbr_offset;
celt_int32 vbr_count;
- celt_int32 vbr_rate; /* Target number of 16th bits per frame */
+ celt_int32 vbr_rate_norm; /* Target number of 16th bits per frame */
celt_word16 * restrict preemph_memE;
celt_sig * restrict preemph_memD;
@@ -167,7 +167,7 @@
st->start = 0;
st->end = st->mode->nbEBands;
- st->vbr_rate = 0;
+ st->vbr_rate_norm = 0;
st->pitch_enabled = 1;
st->pitch_permitted = 1;
st->pitch_available = 1;
@@ -677,6 +677,7 @@
int gain_id=0;
int norm_rate;
int LM, M;
+ celt_int32 vbr_rate=0;
SAVE_STACK;
if (check_encoder(st) != CELT_OK)
@@ -890,13 +891,14 @@
ALLOC(fine_quant, st->mode->nbEBands, int);
ALLOC(pulses, st->mode->nbEBands, int);
+ vbr_rate = M*st->vbr_rate_norm;
/* Computes the max bit-rate allowed in VBR more to avoid busting the budget */
- if (st->vbr_rate>0)
+ if (st->vbr_rate_norm>0)
{celt_int32 vbr_bound, max_allowed;
- vbr_bound = st->vbr_rate;
- max_allowed = (st->vbr_rate + vbr_bound - st->vbr_reservoir)>>(BITRES+3);
+ vbr_bound = vbr_rate;
+ max_allowed = (vbr_rate + vbr_bound - st->vbr_reservoir)>>(BITRES+3);
if (max_allowed < 4)
max_allowed = 4;
if (max_allowed < nbCompressedBytes)
@@ -913,12 +915,12 @@
if (coarse_needed > nbCompressedBytes)
coarse_needed = nbCompressedBytes;
/* Variable bitrate */
- if (st->vbr_rate>0)
+ if (vbr_rate>0)
{celt_word16 alpha;
celt_int32 delta;
/* The target rate in 16th bits per frame */
- celt_int32 target=st->vbr_rate;
+ celt_int32 target=vbr_rate;
/* Shortblocks get a large boost in bitrate, but since they
are uncommon long blocks are not greatly effected */
@@ -944,7 +946,7 @@
alpha = QCONST16(.001f,15);
/* By how much did we "miss" the target on that frame */
- delta = (8<<BITRES)*(celt_int32)target - st->vbr_rate;
+ delta = (8<<BITRES)*(celt_int32)target - vbr_rate;
/* How many bits have we used in excess of what we're allowed */
st->vbr_reservoir += delta;
/*printf ("%d\n", st->vbr_reservoir);*/@@ -1189,14 +1191,14 @@
case CELT_SET_VBR_RATE_REQUEST:
{celt_int32 value = va_arg(ap, celt_int32);
- int N = st->mode->nbShortMdcts*st->mode->shortMdctSize;
+ int frame_rate;
+ int N = st->mode->shortMdctSize;
if (value<0)
goto bad_arg;
if (value>3072000)
value = 3072000;
- /* FIXME: We need to find a better way to do this if N is going to change */
- st->vbr_rate = ((st->mode->Fs<<3)+(N>>1))/N;
- st->vbr_rate = ((value<<7)+(st->vbr_rate>>1))/st->vbr_rate;
+ frame_rate = ((st->mode->Fs<<3)+(N>>1))/N;
+ st->vbr_rate_norm = ((value<<(BITRES+3))+(frame_rate>>1))/frame_rate;
}
break;
case CELT_RESET_STATE: