Making sure the VBR controller never busts the number of bytes allowed

This commit is contained in:
Jean-Marc Valin 2009-10-22 00:12:31 -04:00
parent 25767d1ca7
commit 45f1110583

View file

@ -802,7 +802,7 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
/* 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);
target=IMIN(nbCompressedBytes,target);
/* Make the adaptation coef (alpha) higher at the beginning */
if (st->vbr_count < 990)
{
@ -813,7 +813,7 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
alpha = QCONST16(.001f,15);
/* By how much did we "miss" the target on that frame */
delta = (8<<BITRES)*(celt_int32)nbCompressedBytes - st->vbr_rate;
delta = (8<<BITRES)*(celt_int32)target - 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);*/
@ -829,10 +829,11 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig * pcm, celt_sig
/* 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;
target += adjust;
/*printf ("+%d\n", adjust);*/
}
if (target < nbCompressedBytes)
nbCompressedBytes = target;
/* This moves the raw bits to take into account the new compressed size */
ec_byte_shrink(&buf, nbCompressedBytes);
}