ref: 6ba0b350fb1299b8ec7d1e84eb37b7e6d192e624
parent: 6e4b9dc034d19340930688f46968a1d68cb65129
author: Jean-Marc Valin <[email protected]>
date: Mon Dec 20 06:40:30 EST 2010
Being a bit more careful about enabling the post-filter
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -752,6 +752,7 @@
int intensity=0;
int dual_stereo=0;
int effectiveBytes;
+ celt_word16 pf_threshold;
SAVE_STACK;
if (nbCompressedBytes<0 || pcm==NULL)
@@ -841,14 +842,28 @@
if (pitch_index > COMBFILTER_MAXPERIOD)
pitch_index = COMBFILTER_MAXPERIOD;
gain1 = MULT16_16_Q15(QCONST16(.7f,15),gain1);
- if (gain1 > QCONST16(.6f,15))
- gain1 = QCONST16(.6f,15);
- if (ABS16(gain1-st->prefilter_gain)<QCONST16(.1,15))
- gain1=st->prefilter_gain;
} else {gain1 = 0;
}
- if (gain1<QCONST16(.2f,15) || (nbAvailableBytes<30 && gain1<QCONST16(.4f,15)))
+
+ /* Gain threshold for enabling the prefilter/postfilter */
+ pf_threshold = QCONST16(.2f,15);
+
+ /* Adjusting the threshold based on rate and continuity */
+ if (abs(pitch_index-st->prefilter_period)*10>pitch_index)
+ pf_threshold += QCONST16(.2f,15);
+ if (nbAvailableBytes<25)
+ pf_threshold += QCONST16(.1f,15);
+ if (nbAvailableBytes<35)
+ pf_threshold += QCONST16(.1f,15);
+ if (st->prefilter_gain > QCONST16(.4f,15))
+ pf_threshold -= QCONST16(.1f,15);
+ if (st->prefilter_gain > QCONST16(.55f,15))
+ pf_threshold -= QCONST16(.1f,15);
+
+ /* Hard threshold at 0.2 */
+ pf_threshold = MAX16(pf_threshold, QCONST16(.2f,15));
+ if (gain1<pf_threshold)
{ec_enc_bit_logp(enc, 0, 1);
gain1 = 0;
@@ -855,6 +870,12 @@
} else {int qg;
int octave;
+
+ if (gain1 > QCONST16(.6f,15))
+ gain1 = QCONST16(.6f,15);
+ if (ABS16(gain1-st->prefilter_gain)<QCONST16(.1,15))
+ gain1=st->prefilter_gain;
+
#ifdef FIXED_POINT
qg = ((gain1+2048)>>12)-2;
#else