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Surround masking rewrite

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The channel energy is now computed using an MDCT in the multi-stream
encoder rather than computing the energy of the stereo downmix.
This commit is contained in:
Jean-Marc Valin 2013-08-30 21:58:02 -04:00
parent 02fed471a4
commit fdceae89bf
4 changed files with 254 additions and 248 deletions
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30
celt/celt_encoder.c
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@ -111,7 +111,6 @@ struct OpusCustomEncoder {
opus_val32 overlap_max;
opus_val16 stereo_saving;
int intensity;
opus_val16 *energy_save;
opus_val16 *energy_mask;
opus_val16 spec_avg;
@ -452,7 +451,7 @@ static void compute_mdcts(const CELTMode *mode, int shortBlocks, celt_sig * OPUS
}
static void preemphasis(const opus_val16 * OPUS_RESTRICT pcmp, celt_sig * OPUS_RESTRICT inp,
void preemphasis(const opus_val16 * OPUS_RESTRICT pcmp, celt_sig * OPUS_RESTRICT inp,
int N, int CC, int upsample, const opus_val16 *coef, celt_sig *mem, int clip)
{
int i;
@ -1526,35 +1525,18 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
}
}
amp2Log2(mode, effEnd, st->end, bandE, bandLogE, C);
if (st->energy_save)
{
opus_val16 offset = shortBlocks?HALF16(SHL16(LM, DB_SHIFT)):0;
#ifdef FIXED_POINT
/* Compensate for the 1/8 gain we apply in the fixed-point downshift to avoid overflows. */
offset -= QCONST16(3.0f, DB_SHIFT);
#endif
for(i=0;i<C*nbEBands;i++)
st->energy_save[i]=bandLogE[i]-offset;
st->energy_save=NULL;
}
/* This computes how much masking takes place between surround channels */
if (st->energy_mask&&!st->lfe)
{
opus_val32 mask_avg=0;
opus_val16 offset = shortBlocks?HALF16(SHL16(LM, DB_SHIFT)):0;
for (c=0;c<C;c++)
{
opus_val16 followE, followMask;
followE = followMask = -QCONST16(14.f, DB_SHIFT);
for(i=0;i<st->end;i++)
{
/* We use a simple follower to approximate the masking spreading function. */
followE = MAX16(followE-QCONST16(1.f, DB_SHIFT), bandLogE[nbEBands*c+i]-offset);
followMask = MAX16(followMask-QCONST16(1.f, DB_SHIFT), st->energy_mask[nbEBands*c+i]);
mask_avg += followE-followMask;
mask_avg += st->energy_mask[nbEBands*c+i];
}
}
surround_masking = DIV32_16(mask_avg,C*st->end) + QCONST16(.7f, DB_SHIFT);
surround_masking = DIV32_16(mask_avg,C*st->end);
surround_masking = MIN16(MAX16(surround_masking, -QCONST16(2.f, DB_SHIFT)), QCONST16(.2f, DB_SHIFT));
surround_masking -= HALF16(HALF16(surround_masking));
}
@ -2261,12 +2243,6 @@ int opus_custom_encoder_ctl(CELTEncoder * OPUS_RESTRICT st, int request, ...)
st->lfe = value;
}
break;
case OPUS_SET_ENERGY_SAVE_REQUEST:
{
opus_val16 *value = va_arg(ap, opus_val16*);
st->energy_save=value;
}
break;
case OPUS_SET_ENERGY_MASK_REQUEST:
{
opus_val16 *value = va_arg(ap, opus_val16*);