highperfocused/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Alpha: fix dct_unquantize_h263_inter/intra_axp()

Browse Source 
Originally committed as revision 16660 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Måns Rullgård
2009-01-17 21:44:56 +00:00
parent 2323ac0154
commit 1617220799
1 changed files with 16 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
libavcodec/alpha/mpegvideo_alpha.c
View File

@@ -30,25 +30,29 @@ static void dct_unquantize_h263_intra_axp(MpegEncContext *s, DCTELEM *block,
uint64_t qmul, qadd; uint64_t qmul, qadd;
uint64_t correction; uint64_t correction;
DCTELEM *orig_block = block; DCTELEM *orig_block = block;
DCTELEM block0; /* might not be used uninitialized */ DCTELEM block0 = block[0];
qadd = WORD_VEC((qscale - 1) | 1);
qmul = qscale << 1; qmul = qscale << 1;
/* This mask kills spill from negative subwords to the next subword. */ /* This mask kills spill from negative subwords to the next subword. */
correction = WORD_VEC((qmul - 1) + 1); /* multiplication / addition */ correction = WORD_VEC(qmul * 255 >> 8);
if (!s->h263_aic) { if (!s->h263_aic) {
if (n < 4) if (n < 4)
block0 = block[0] * s->y_dc_scale; block0 *= s->y_dc_scale;
else else
block0 = block[0] * s->c_dc_scale; block0 *= s->c_dc_scale;
qadd = WORD_VEC((qscale - 1) | 1);
} else { } else {
qadd = 0; qadd = 0;
} }
n_coeffs = 63; // does not always use zigzag table
if(s->ac_pred)
n_coeffs = 63;
else
n_coeffs = s->inter_scantable.raster_end[s->block_last_index[n]];
for(i = 0; i <= n_coeffs; block += 4, i += 4) { for(i = 0; i <= n_coeffs; block += 4, i += 4) {
uint64_t levels, negmask, zeros, add; uint64_t levels, negmask, zeros, add, sub;
levels = ldq(block); levels = ldq(block);
if (levels == 0) if (levels == 0)
@@ -73,18 +77,16 @@ static void dct_unquantize_h263_intra_axp(MpegEncContext *s, DCTELEM *block,
levels *= qmul; levels *= qmul;
levels -= correction & (negmask << 16); levels -= correction & (negmask << 16);
/* Negate qadd for negative levels. */ add = qadd & ~negmask;
add = qadd ^ negmask; sub = qadd & negmask;
add += WORD_VEC(0x0001) & negmask;
/* Set qadd to 0 for levels == 0. */ /* Set qadd to 0 for levels == 0. */
add = zap(add, zeros); add = zap(add, zeros);
levels += add; levels += add;
levels -= sub;
stq(levels, block); stq(levels, block);
} }
if (s->mb_intra && !s->h263_aic)
orig_block[0] = block0; orig_block[0] = block0;
} }
@@ -100,7 +102,7 @@ static void dct_unquantize_h263_inter_axp(MpegEncContext *s, DCTELEM *block,
/* This mask kills spill from negative subwords to the next subword. */ /* This mask kills spill from negative subwords to the next subword. */
correction = WORD_VEC((qmul - 1) + 1); /* multiplication / addition */ correction = WORD_VEC((qmul - 1) + 1); /* multiplication / addition */
n_coeffs = s->intra_scantable.raster_end[s->block_last_index[n]]; n_coeffs = s->inter_scantable.raster_end[s->block_last_index[n]];
for(i = 0; i <= n_coeffs; block += 4, i += 4) { for(i = 0; i <= n_coeffs; block += 4, i += 4) {
uint64_t levels, negmask, zeros, add; uint64_t levels, negmask, zeros, add;