Commit bd5d54ad authored by Jean-Marc Valin's avatar Jean-Marc Valin
Browse files

New VBR rate controller that doesn't allow more than one frame worth of excess

bit-rate
parent 328b8bd7
......@@ -92,7 +92,13 @@ struct CELTEncoder {
int fold_decision;
celt_word16 gain_prod;
int VBR_rate; /* Target number of 16th bits per frame */
/* VBR-related parameters */
celt_int32 vbr_reservoir;
celt_int32 vbr_drift;
celt_int32 vbr_offset;
celt_int32 vbr_count;
celt_int32 vbr_rate; /* Target number of 16th bits per frame */
celt_word16 * restrict preemph_memE;
celt_sig * restrict preemph_memD;
......@@ -133,6 +139,16 @@ CELTEncoder *celt_encoder_create(const CELTMode *mode, int channels, int *error)
*error = CELT_INVALID_MODE;
return NULL;
}
#ifdef DISABLE_STEREO
if (channels > 1)
{
celt_warning("Stereo support was disable from this build");
if (error)
*error = CELT_BAD_ARG;
return NULL;
}
#endif
if (channels < 0 || channels > 2)
{
celt_warning("Only mono and stereo supported");
......@@ -158,7 +174,7 @@ CELTEncoder *celt_encoder_create(const CELTMode *mode, int channels, int *error)
st->overlap = mode->overlap;
st->channels = channels;
st->VBR_rate = 0;
st->vbr_rate = 0;
st->pitch_enabled = 1;
st->pitch_permitted = 1;
st->pitch_available = 1;
......@@ -662,7 +678,7 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
compute_band_energies(st->mode, freq, bandE, C);
for (i=0;i<st->mode->nbEBands*C;i++)
bandLogE[i] = amp2Log(bandE[i]);
/* Band normalisation */
normalise_bands(st->mode, freq, X, bandE, C);
if (!shortBlocks && !folding_decision(st->mode, X, &st->tonal_average, &st->fold_decision, C))
......@@ -754,25 +770,69 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
coarse_needed = ((coarse_needed*3-1)>>3)+1;
/* Variable bitrate */
if (st->VBR_rate>0)
if (st->vbr_rate>0)
{
celt_word16 alpha;
celt_int32 delta, vbr_bound;
/* The target rate in 16th bits per frame */
int target=st->VBR_rate;
celt_int32 target=st->vbr_rate;
/* Shortblocks get a large boost in bitrate, but since they
are uncommon long blocks are not greatly effected */
if (shortBlocks)
target*=2;
else if (st->mode->nbShortMdcts > 1)
target-=(target+14)/28;
target-=(target+14)/28;
/* The average energy is removed from the target and the actual
energy added*/
target=target-588+ec_enc_tell(&enc, BITRES);
target=target+st->vbr_offset-588+ec_enc_tell(&enc, BITRES);
/* In VBR mode the frame size must not be reduced so much that it would result in the coarse energy busting its budget */
target=IMAX(coarse_needed,(target+64)/128);
nbCompressedBytes=IMIN(nbCompressedBytes,target);
/* Make the adaptation coef (alpha) higher at the beginning */
if (st->vbr_count < 990)
{
st->vbr_count++;
alpha = celt_rcp(SHL32(EXTEND32(st->vbr_count+10),16));
/*printf ("%d %d\n", st->vbr_count+10, alpha);*/
} else
alpha = QCONST16(.001f,15);
/* By how much did we "miss" the target on that frame */
delta = (8<<BITRES)*(celt_int32)nbCompressedBytes - st->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);*/
/* Compute the offset we need to apply in order to reach the target */
st->vbr_drift += MULT16_32_Q15(alpha,delta-st->vbr_offset-st->vbr_drift);
st->vbr_offset = -st->vbr_drift;
/*printf ("%d\n", st->vbr_drift);*/
/* We could use any multiple of vbr_rate as bound (depending on the delay) */
vbr_bound = st->vbr_rate;
if (st->vbr_reservoir > vbr_bound)
{
/* Busted the reservoir -- reduce the rate */
int adjust = 1+(st->vbr_reservoir-vbr_bound-1)/(8<<BITRES);
nbCompressedBytes -= adjust;
st->vbr_reservoir -= adjust*(8<<BITRES);
st->vbr_offset -= 8<<BITRES;
/*printf ("-%d\n", adjust);*/
} else if (st->vbr_reservoir < 0)
{
/* We're under the min value -- increase rate */
int adjust = 1-(st->vbr_reservoir-1)/(8<<BITRES);
st->vbr_reservoir += adjust*(8<<BITRES);
nbCompressedBytes += adjust;
st->vbr_offset += 8<<BITRES;
/*printf ("+%d\n", adjust);*/
}
/* This moves the raw bits to take into account the new compressed size */
ec_byte_shrink(&buf, nbCompressedBytes);
}
......@@ -962,8 +1022,8 @@ int celt_encoder_ctl(CELTEncoder * restrict st, int request, ...)
goto bad_arg;
if (value>3072000)
value = 3072000;
st->VBR_rate = ((st->mode->Fs<<3)+(st->block_size>>1))/st->block_size;
st->VBR_rate = ((value<<7)+(st->VBR_rate>>1))/st->VBR_rate;
st->vbr_rate = ((st->mode->Fs<<3)+(st->block_size>>1))/st->block_size;
st->vbr_rate = ((value<<7)+(st->vbr_rate>>1))/st->vbr_rate;
}
break;
case CELT_RESET_STATE:
......@@ -1066,6 +1126,16 @@ CELTDecoder *celt_decoder_create(const CELTMode *mode, int channels, int *error)
*error = CELT_INVALID_MODE;
return NULL;
}
#ifdef DISABLE_STEREO
if (channels > 1)
{
celt_warning("Stereo support was disable from this build");
if (error)
*error = CELT_BAD_ARG;
return NULL;
}
#endif
if (channels < 0 || channels > 2)
{
celt_warning("Only mono and stereo supported");
......
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