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Partially fix CDLMS prediction

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This commit is contained in:
Mashiat Sarker Shakkhar
2011-12-08 03:57:21 +06:00
parent 460bec6800
commit c5cd231151
1 changed files with 58 additions and 60 deletions
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118
libavcodec/wmalosslessdec.c
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@@ -776,11 +776,12 @@ static void reset_codec(WmallDecodeCtx *s)
s->mclms_recent = s->mclms_order * s->num_channels; s->mclms_recent = s->mclms_order * s->num_channels;
for (ich = 0; ich < s->num_channels; ich++) { for (ich = 0; ich < s->num_channels; ich++) {
for (ilms = 0; ilms < s->cdlms_ttl[ich]; ilms++) for (ilms = 0; ilms < s->cdlms_ttl[ich]; ilms++)
s->cdlms[ich][ilms].recent = s->cdlms[ich][ilms].order - 1; s->cdlms[ich][ilms].recent = s->cdlms[ich][ilms].order;
/* first sample of a seekable subframe is considered as the starting of /* first sample of a seekable subframe is considered as the starting of
a transient area which is samples_per_frame samples long */ a transient area which is samples_per_frame samples long */
s->channel[ich].transient_counter = s->samples_per_frame; s->channel[ich].transient_counter = s->samples_per_frame;
s->transient[ich] = 1; s->transient[ich] = 1;
s->transient_pos[ich] = 0;
} }
} }
@@ -875,7 +876,7 @@ static void revert_mclms(WmallDecodeCtx *s, int tile_size)
static int lms_predict(WmallDecodeCtx *s, int ich, int ilms) static int lms_predict(WmallDecodeCtx *s, int ich, int ilms)
{ {
int16_t pred = 0; int pred = 0;
int icoef; int icoef;
int recent = s->cdlms[ich][ilms].recent; int recent = s->cdlms[ich][ilms].recent;
@@ -883,39 +884,53 @@ static int lms_predict(WmallDecodeCtx *s, int ich, int ilms)
pred += s->cdlms[ich][ilms].coefs[icoef] * pred += s->cdlms[ich][ilms].coefs[icoef] *
s->cdlms[ich][ilms].lms_prevvalues[icoef + recent]; s->cdlms[ich][ilms].lms_prevvalues[icoef + recent];
pred += (1 << (s->cdlms[ich][ilms].scaling - 1)); //pred += (1 << (s->cdlms[ich][ilms].scaling - 1));
/* XXX: Table 29 has: /* XXX: Table 29 has:
iPred >= cdlms[iCh][ilms].scaling; iPred >= cdlms[iCh][ilms].scaling;
seems to me like a missing > */ seems to me like a missing > */
pred >>= s->cdlms[ich][ilms].scaling; //pred >>= s->cdlms[ich][ilms].scaling;
return pred; return pred;
} }
static void lms_update(WmallDecodeCtx *s, int ich, int ilms, int16_t residue, int16_t pred) static void lms_update(WmallDecodeCtx *s, int ich, int ilms, int input, int residue)
{ {
int16_t icoef; int icoef;
int recent = s->cdlms[ich][ilms].recent; int recent = s->cdlms[ich][ilms].recent;
int16_t range = (1 << s->bits_per_sample - 1) - 1; int range = 1 << s->bits_per_sample - 1;
int bps = s->bits_per_sample > 16 ? 4 : 2; // bytes per sample int bps = s->bits_per_sample > 16 ? 4 : 2; // bytes per sample
int16_t input = residue + pred;
if (residue > 0) { if (residue < 0) {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].coefs[icoef] +=
s->cdlms[ich][ilms].lms_updates[icoef + recent];
} else {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++) for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].coefs[icoef] -= s->cdlms[ich][ilms].coefs[icoef] -=
s->cdlms[ich][ilms].lms_updates[icoef + recent];
} else if (residue > 0) {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].coefs[icoef] +=
s->cdlms[ich][ilms].lms_updates[icoef + recent]; /* spec mistakenly s->cdlms[ich][ilms].lms_updates[icoef + recent]; /* spec mistakenly
dropped the recent */ dropped the recent */
} }
s->cdlms[ich][ilms].recent--;
s->cdlms[ich][ilms].lms_prevvalues[recent] = av_clip(input, -range, range - 1);
if (input > pred) if (recent)
s->cdlms[ich][ilms].lms_updates[recent] = s->update_speed[ich]; recent--;
else if (input < pred) else {
/* XXX: This memcpy()s will probably fail if a fixed 32-bit buffer is used.
follow kshishkov's suggestion of using a union. */
memcpy(&s->cdlms[ich][ilms].lms_prevvalues[s->cdlms[ich][ilms].order],
s->cdlms[ich][ilms].lms_prevvalues,
bps * s->cdlms[ich][ilms].order);
memcpy(&s->cdlms[ich][ilms].lms_updates[s->cdlms[ich][ilms].order],
s->cdlms[ich][ilms].lms_updates,
bps * s->cdlms[ich][ilms].order);
recent = s->cdlms[ich][ilms].order - 1;
}
s->cdlms[ich][ilms].lms_prevvalues[recent] = av_clip(input, -range, range - 1);
if (!input)
s->cdlms[ich][ilms].lms_updates[recent] = 0;
else if (input < 0)
s->cdlms[ich][ilms].lms_updates[recent] = -s->update_speed[ich]; s->cdlms[ich][ilms].lms_updates[recent] = -s->update_speed[ich];
else
s->cdlms[ich][ilms].lms_updates[recent] = s->update_speed[ich];
/* XXX: spec says: /* XXX: spec says:
cdlms[iCh][ilms].updates[iRecent + cdlms[iCh][ilms].order >> 4] >>= 2; cdlms[iCh][ilms].updates[iRecent + cdlms[iCh][ilms].order >> 4] >>= 2;
@@ -925,21 +940,9 @@ static void lms_update(WmallDecodeCtx *s, int ich, int ilms, int16_t residue, in
seperate buffers? Here I've assumed that the two are same which makes seperate buffers? Here I've assumed that the two are same which makes
more sense to me. more sense to me.
*/ */
s->cdlms[ich][ilms].lms_updates[recent + s->cdlms[ich][ilms].order >> 4] >>= 2; s->cdlms[ich][ilms].lms_updates[recent + (s->cdlms[ich][ilms].order >> 4)] >>= 2;
s->cdlms[ich][ilms].lms_updates[recent + s->cdlms[ich][ilms].order >> 3] >>= 1; s->cdlms[ich][ilms].lms_updates[recent + (s->cdlms[ich][ilms].order >> 3)] >>= 1;
/* XXX: recent + (s->cdlms[ich][ilms].order >> 4) ? */ s->cdlms[ich][ilms].recent = recent;
if (s->cdlms[ich][ilms].recent == 0) {
/* XXX: This memcpy()s will probably fail if a fixed 32-bit buffer is used.
follow kshishkov's suggestion of using a union. */
memcpy(s->cdlms[ich][ilms].lms_prevvalues + s->cdlms[ich][ilms].order,
s->cdlms[ich][ilms].lms_prevvalues,
bps * s->cdlms[ich][ilms].order);
memcpy(s->cdlms[ich][ilms].lms_updates + s->cdlms[ich][ilms].order,
s->cdlms[ich][ilms].lms_updates,
bps * s->cdlms[ich][ilms].order);
s->cdlms[ich][ilms].recent = s->cdlms[ich][ilms].order;
}
} }
static void use_high_update_speed(WmallDecodeCtx *s, int ich) static void use_high_update_speed(WmallDecodeCtx *s, int ich)
@@ -974,33 +977,23 @@ static void use_normal_update_speed(WmallDecodeCtx *s, int ich)
} }
} }
static void revert_cdlms(WmallDecodeCtx *s, int tile_size) static void revert_cdlms(WmallDecodeCtx *s, int ch, int coef_begin, int coef_end)
{ {
int icoef, ich; int icoef;
int16_t pred, channel_coeff; int pred;
int ilms, num_lms; int ilms, num_lms;
int residue, input;
for (ich = 0; ich < s->num_channels; ich++) { num_lms = s->cdlms_ttl[ch];
if (!s->is_channel_coded[ich]) for (ilms = num_lms - 1; ilms >= 0; ilms--) {
continue; //s->cdlms[ch][ilms].recent = s->cdlms[ch][ilms].order;
num_lms = s->cdlms_ttl[ich]; for (icoef = coef_begin; icoef < coef_end; icoef++) {
for (icoef = 0; icoef < tile_size; icoef++) { pred = 1 << (s->cdlms[ch][ilms].scaling - 1);
channel_coeff = s->channel_residues[ich][icoef]; residue = s->channel_residues[ch][icoef];
if (icoef == s->transient_pos[ich]) { pred += lms_predict(s, ch, ilms);
s->transient[ich] = 1; input = residue + (pred >> s->cdlms[ch][ilms].scaling);
use_high_update_speed(s, ich); lms_update(s, ch, ilms, input, residue);
} s->channel_residues[ch][icoef] = input;
for (ilms = num_lms - 1; ilms >= 0; ilms--) {
pred = lms_predict(s, ich, ilms);
lms_update(s, ich, ilms, channel_coeff, pred);
channel_coeff += pred;
}
if (s->transient[ich]) {
--s->channel[ich].transient_counter;
if(!s->channel[ich].transient_counter)
use_normal_update_speed(s, ich);
}
s->channel_coeffs[ich][icoef] = channel_coeff;
} }
} }
} }
@@ -1130,10 +1123,15 @@ static int decode_subframe(WmallDecodeCtx *s)
} }
} else { } else {
for(i = 0; i < s->num_channels; i++) for(i = 0; i < s->num_channels; i++)
if(s->is_channel_coded[i]) if(s->is_channel_coded[i]) {
decode_channel_residues(s, i, subframe_len); decode_channel_residues(s, i, subframe_len);
if (s->seekable_tile)
use_high_update_speed(s, i);
else
use_normal_update_speed(s, i);
revert_cdlms(s, i, 0, subframe_len);
}
} }
revert_cdlms(s, subframe_len);
/** handled one subframe */ /** handled one subframe */