From ae7dc8a13fb61a50204c5b28aac3c1c4c2e1c0dc Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Fri, 13 Sep 2013 15:05:50 -0400
Subject: [PATCH] More surround masking tuning
---
celt/celt_encoder.c | 47 +++++++++++++++++++++++++++++++++++----------
src/opus_encoder.c | 9 ++++++++-
2 files changed, 45 insertions(+), 11 deletions(-)
diff --git a/celt/celt_encoder.c b/celt/celt_encoder.c
index 41c28ab61..12b5581a4 100644
--- a/celt/celt_encoder.c
+++ b/celt/celt_encoder.c
@@ -1538,6 +1538,8 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
if (st->start==0&&st->energy_mask&&!st->lfe)
{
int mask_end;
+ int midband;
+ int count_dynalloc;
opus_val32 mask_avg=0;
opus_val32 diff=0;
int count=0;
@@ -1546,38 +1548,63 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
{
for(i=0;i<mask_end;i++)
{
- mask_avg += st->energy_mask[nbEBands*c+i]*(eBands[i+1]-eBands[i]);
- count += (eBands[i+1]-eBands[i]);
- diff += st->energy_mask[i+c*nbEBands]*(opus_int32)(1+2*i-mask_end);
+ opus_val16 mask;
+ mask = MAX16(MIN16(st->energy_mask[nbEBands*c+i],
+ QCONST16(.25f, DB_SHIFT)), -QCONST16(2.0f, DB_SHIFT));
+ if (mask > 0)
+ mask = HALF16(mask);
+ mask_avg += MULT16_16(mask, eBands[i+1]-eBands[i]);
+ count += eBands[i+1]-eBands[i];
+ diff += MULT16_16(mask, 1+2*i-mask_end);
}
}
mask_avg = DIV32_16(mask_avg,count);
- /* Just being conservative here */
- mask_avg -= HALF32(HALF32(mask_avg));
- mask_avg = MAX16(mask_avg, -QCONST16(2.f, DB_SHIFT));
diff = diff*6/(C*(mask_end-1)*(mask_end+1)*mask_end);
/* Again, being conservative */
diff = HALF32(diff);
diff = MAX32(MIN32(diff, QCONST32(.031f, DB_SHIFT)), -QCONST32(.031f, DB_SHIFT));
+ /* Find the band that's in the middle of the coded spectrum */
+ for (midband=0;eBands[midband+1] < eBands[mask_end]/2;midband++);
+ count_dynalloc=0;
for(i=0;i<mask_end;i++)
{
opus_val32 lin;
opus_val16 unmask;
- lin = mask_avg + HALF32(diff*(1+2*i-mask_end));
+ lin = mask_avg + diff*(i-midband);
if (C==2)
- unmask = MAX16(st->energy_mask[i], st->energy_mask[nbEBands+i]) - lin;
+ unmask = MAX16(st->energy_mask[i], st->energy_mask[nbEBands+i]);
else
- unmask = st->energy_mask[i] - lin;
+ unmask = st->energy_mask[i];
+ unmask = MIN16(unmask, QCONST16(.0f, DB_SHIFT));
+ unmask -= lin;
if (unmask > QCONST16(.25f, DB_SHIFT))
{
surround_dynalloc[i] = unmask - QCONST16(.25f, DB_SHIFT);
+ count_dynalloc++;
+ }
+ }
+ if (count_dynalloc>=3)
+ {
+ /* If we need dynalloc in many bands, it's probably because our
+ initial masking rate was too low. */
+ mask_avg += QCONST16(.25f, DB_SHIFT);
+ if (mask_avg>0)
+ {
+ /* Something went really wrong in the original calculations,
+ disabling masking. */
+ mask_avg = 0;
+ diff = 0;
+ for(i=0;i<mask_end;i++)
+ surround_dynalloc[i] = 0;
+ } else {
+ for(i=0;i<mask_end;i++)
+ surround_dynalloc[i] = MAX16(0, surround_dynalloc[i]-QCONST16(.25f, DB_SHIFT));
}
}
/* Convert to 1/64th units used for the trim */
surround_trim = 64*diff;
/*printf("%d %d ", mask_avg, surround_trim);*/
surround_masking = mask_avg;
- surround_masking = MIN16(MAX16(surround_masking, -QCONST16(2.f, DB_SHIFT)), QCONST16(.0f, DB_SHIFT));
}
/* Temporal VBR (but not for LFE) */
if (!st->lfe)
diff --git a/src/opus_encoder.c b/src/opus_encoder.c
index 5599d203f..071156771 100644
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -1499,7 +1499,14 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
for (c=0;c<st->channels;c++)
{
for(i=0;i<end;i++)
- mask_sum += st->energy_masking[21*c+i];
+ {
+ opus_val16 mask;
+ mask = MAX16(MIN16(st->energy_masking[21*c+i],
+ QCONST16(.25f, DB_SHIFT)), -QCONST16(2.0f, DB_SHIFT));
+ if (mask > 0)
+ mask = HALF16(mask);
+ mask_sum += mask;
+ }
}
/* Conservative rate reduction, we cut the masking in half */
masking_depth = HALF16(mask_sum / end*st->channels);
--
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