From 416dc73f280809c30a8162a715f5f84ca82176d5 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Wed, 25 Jul 2012 21:15:19 -0400
Subject: [PATCH] Smoother intensity stereo decision thresholds
We now have rates for each possible threshold. This also adds some
histeresis but it's not that useful for now because the effective rate
doesn't changes from frame to frame (unless one changes the target rate).
This change also has the side effect of lowering the intensity stereo
point for 64 kb/s to band 15 (instead of 16).
---
celt/celt.c | 36 +++++++++++++++---------------------
1 file changed, 15 insertions(+), 21 deletions(-)
diff --git a/celt/celt.c b/celt/celt.c
index 02316bcb6..0dd22b6f1 100644
--- a/celt/celt.c
+++ b/celt/celt.c
@@ -190,6 +190,7 @@ struct OpusCustomEncoder {
opus_int32 vbr_count;
opus_val16 overlap_max;
opus_val16 stereo_saving;
+ int intensity;
#ifdef RESYNTH
celt_sig syn_mem[2][2*MAX_PERIOD];
@@ -986,7 +987,6 @@ int celt_encode_with_ec(CELTEncoder * restrict st, const opus_val16 * pcm, int f
int alloc_trim;
int pitch_index=COMBFILTER_MINPERIOD;
opus_val16 gain1 = 0;
- int intensity=0;
int dual_stereo=0;
int effectiveBytes;
opus_val16 pf_threshold;
@@ -1569,33 +1569,27 @@ int celt_encode_with_ec(CELTEncoder * restrict st, const opus_val16 * pcm, int f
if (LM!=0)
dual_stereo = stereo_analysis(st->mode, X, LM, N);
+ static const opus_val16 intensity_thresholds[21]=
+ /* 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 off*/
+ { 16,21,23,25,27,29,31,33,35,38,42,46,50,54,58,63,68,75,84,102,130};
+ static const opus_val16 intensity_histeresis[21]=
+ { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 4, 5, 6, 8, 12};
+
/* Account for coarse energy */
effectiveRate = (8*effectiveBytes - 80)>>LM;
/* effectiveRate in kb/s */
effectiveRate = 2*effectiveRate/5;
- if (effectiveRate<35)
- intensity = 8;
- else if (effectiveRate<50)
- intensity = 12;
- else if (effectiveRate<68)
- intensity = 16;
- else if (effectiveRate<84)
- intensity = 18;
- else if (effectiveRate<102)
- intensity = 19;
- else if (effectiveRate<130)
- intensity = 20;
- else
- intensity = 100;
- intensity = IMIN(st->end,IMAX(st->start, intensity));
+
+ st->intensity = hysteresis_decision(effectiveRate, intensity_thresholds, intensity_histeresis, 21, st->intensity);
+ st->intensity = IMIN(st->end,IMAX(st->start, st->intensity));
}
alloc_trim = 5;
if (tell+(6<<BITRES) <= total_bits - total_boost)
{
alloc_trim = alloc_trim_analysis(st->mode, X, bandLogE,
- st->end, LM, C, N, &st->analysis, &st->stereo_saving, tf_estimate, intensity);
+ st->end, LM, C, N, &st->analysis, &st->stereo_saving, tf_estimate, st->intensity);
ec_enc_icdf(enc, alloc_trim, trim_icdf, 7);
tell = ec_tell_frac(enc);
}
@@ -1614,7 +1608,7 @@ int celt_encode_with_ec(CELTEncoder * restrict st, const opus_val16 * pcm, int f
coded_bands = st->lastCodedBands ? st->lastCodedBands : st->mode->nbEBands;
coded_bins = st->mode->eBands[coded_bands]<<LM;
if (C==2)
- coded_bins += st->mode->eBands[IMIN(intensity, coded_bands)]<<LM;
+ coded_bins += st->mode->eBands[IMIN(st->intensity, coded_bands)]<<LM;
/* Don't attempt to use more than 510 kb/s, even for frames smaller than 20 ms.
The CELT allocator will just not be able to use more than that anyway. */
@@ -1632,7 +1626,7 @@ int celt_encode_with_ec(CELTEncoder * restrict st, const opus_val16 * pcm, int f
{
int coded_stereo_bands;
int coded_stereo_dof;
- coded_stereo_bands = IMIN(intensity, coded_bands);
+ coded_stereo_bands = IMIN(st->intensity, coded_bands);
coded_stereo_dof = (st->mode->eBands[coded_stereo_bands]<<LM)-coded_stereo_bands;
/*printf("%d %d %d ", coded_stereo_dof, coded_bins, tot_boost);*/
target -= MIN32(target/3, SHR16(MULT16_16(st->stereo_saving,(coded_stereo_dof<<BITRES)),8));
@@ -1744,7 +1738,7 @@ int celt_encode_with_ec(CELTEncoder * restrict st, const opus_val16 * pcm, int f
anti_collapse_rsv = isTransient&&LM>=2&&bits>=((LM+2)<<BITRES) ? (1<<BITRES) : 0;
bits -= anti_collapse_rsv;
codedBands = compute_allocation(st->mode, st->start, st->end, offsets, cap,
- alloc_trim, &intensity, &dual_stereo, bits, &balance, pulses,
+ alloc_trim, &st->intensity, &dual_stereo, bits, &balance, pulses,
fine_quant, fine_priority, C, LM, enc, 1, st->lastCodedBands);
st->lastCodedBands = codedBands;
@@ -1764,7 +1758,7 @@ int celt_encode_with_ec(CELTEncoder * restrict st, const opus_val16 * pcm, int f
/* Residual quantisation */
ALLOC(collapse_masks, C*st->mode->nbEBands, unsigned char);
quant_all_bands(1, st->mode, st->start, st->end, X, C==2 ? X+N : NULL, collapse_masks,
- bandE, pulses, shortBlocks, st->spread_decision, dual_stereo, intensity, tf_res,
+ bandE, pulses, shortBlocks, st->spread_decision, dual_stereo, st->intensity, tf_res,
nbCompressedBytes*(8<<BITRES)-anti_collapse_rsv, balance, enc, LM, codedBands, &st->rng);
if (anti_collapse_rsv > 0)
--
GitLab