libavcodec/mpeg12: Remove "fast" mode

This commit is contained in:
Kieran Kunhya 2023-10-29 15:32:49 +00:00
parent 04b49fb3c5
commit 7d497a1119

View File

@ -233,94 +233,6 @@ end:
return 0;
}
/**
* Changing this would eat up any speed benefits it has.
* Do not use "fast" flag if you need the code to be robust.
*/
static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s,
int16_t *block, int n)
{
int level, i, j, run;
uint8_t *const scantable = s->intra_scantable.permutated;
const int qscale = s->qscale;
{
OPEN_READER(re, &s->gb);
i = -1;
// Special case for first coefficient, no need to add second VLC table.
UPDATE_CACHE(re, &s->gb);
if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
level = (3 * qscale) >> 1;
level = (level - 1) | 1;
if (GET_CACHE(re, &s->gb) & 0x40000000)
level = -level;
block[0] = level;
i++;
SKIP_BITS(re, &s->gb, 2);
if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
goto end;
}
/* now quantify & encode AC coefficients */
for (;;) {
GET_RL_VLC(level, run, re, &s->gb, ff_mpeg1_rl_vlc,
TEX_VLC_BITS, 2, 0);
if (level != 0) {
i += run;
if (i > MAX_INDEX)
break;
j = scantable[i];
level = ((level * 2 + 1) * qscale) >> 1;
level = (level - 1) | 1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
SHOW_SBITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6) + 1;
LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 8);
SKIP_BITS(re, &s->gb, 8);
if (level == -128) {
level = SHOW_UBITS(re, &s->gb, 8) - 256;
SKIP_BITS(re, &s->gb, 8);
} else if (level == 0) {
level = SHOW_UBITS(re, &s->gb, 8);
SKIP_BITS(re, &s->gb, 8);
}
i += run;
if (i > MAX_INDEX)
break;
j = scantable[i];
if (level < 0) {
level = -level;
level = ((level * 2 + 1) * qscale) >> 1;
level = (level - 1) | 1;
level = -level;
} else {
level = ((level * 2 + 1) * qscale) >> 1;
level = (level - 1) | 1;
}
}
block[j] = level;
if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
break;
UPDATE_CACHE(re, &s->gb);
}
end:
LAST_SKIP_BITS(re, &s->gb, 2);
CLOSE_READER(re, &s->gb);
}
check_scantable_index(s, i);
s->block_last_index[n] = i;
return 0;
}
static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
int16_t *block, int n)
{
@ -406,81 +318,6 @@ end:
return 0;
}
/**
* Changing this would eat up any speed benefits it has.
* Do not use "fast" flag if you need the code to be robust.
*/
static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
int16_t *block, int n)
{
int level, i, j, run;
uint8_t *const scantable = s->intra_scantable.permutated;
const int qscale = s->qscale;
OPEN_READER(re, &s->gb);
i = -1;
// special case for first coefficient, no need to add second VLC table
UPDATE_CACHE(re, &s->gb);
if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
level = (3 * qscale) >> 1;
if (GET_CACHE(re, &s->gb) & 0x40000000)
level = -level;
block[0] = level;
i++;
SKIP_BITS(re, &s->gb, 2);
if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
goto end;
}
/* now quantify & encode AC coefficients */
for (;;) {
GET_RL_VLC(level, run, re, &s->gb, ff_mpeg1_rl_vlc, TEX_VLC_BITS, 2, 0);
if (level != 0) {
i += run;
if (i > MAX_INDEX)
break;
j = scantable[i];
level = ((level * 2 + 1) * qscale) >> 1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
SHOW_SBITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6) + 1;
LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 12);
SKIP_BITS(re, &s->gb, 12);
i += run;
if (i > MAX_INDEX)
break;
j = scantable[i];
if (level < 0) {
level = ((-level * 2 + 1) * qscale) >> 1;
level = -level;
} else {
level = ((level * 2 + 1) * qscale) >> 1;
}
}
block[j] = level;
if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF || i > 63)
break;
UPDATE_CACHE(re, &s->gb);
}
end:
LAST_SKIP_BITS(re, &s->gb, 2);
CLOSE_READER(re, &s->gb);
check_scantable_index(s, i);
s->block_last_index[n] = i;
return 0;
}
static inline int mpeg2_decode_block_intra(MpegEncContext *s,
int16_t *block, int n)
{
@ -563,83 +400,6 @@ static inline int mpeg2_decode_block_intra(MpegEncContext *s,
return 0;
}
/**
* Changing this would eat up any speed benefits it has.
* Do not use "fast" flag if you need the code to be robust.
*/
static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
int16_t *block, int n)
{
int level, dc, diff, i, j, run;
int component;
const RL_VLC_ELEM *rl_vlc;
uint8_t *const scantable = s->intra_scantable.permutated;
const uint16_t *quant_matrix;
const int qscale = s->qscale;
/* DC coefficient */
if (n < 4) {
quant_matrix = s->intra_matrix;
component = 0;
} else {
quant_matrix = s->chroma_intra_matrix;
component = (n & 1) + 1;
}
diff = decode_dc(&s->gb, component);
dc = s->last_dc[component];
dc += diff;
s->last_dc[component] = dc;
block[0] = dc * (1 << (3 - s->intra_dc_precision));
i = 0;
if (s->intra_vlc_format)
rl_vlc = ff_mpeg2_rl_vlc;
else
rl_vlc = ff_mpeg1_rl_vlc;
{
OPEN_READER(re, &s->gb);
/* now quantify & encode AC coefficients */
for (;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl_vlc,
TEX_VLC_BITS, 2, 0);
if (level >= 64 || i > 63) {
break;
} else if (level != 0) {
i += run;
j = scantable[i];
level = (level * qscale * quant_matrix[j]) >> 4;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6) + 1;
SKIP_BITS(re, &s->gb, 6);
level = SHOW_SBITS(re, &s->gb, 12);
LAST_SKIP_BITS(re, &s->gb, 12);
i += run;
j = scantable[i];
if (level < 0) {
level = (-level * qscale * quant_matrix[j]) >> 4;
level = -level;
} else {
level = (level * qscale * quant_matrix[j]) >> 4;
}
}
block[j] = level;
}
CLOSE_READER(re, &s->gb);
}
check_scantable_index(s, i);
s->block_last_index[n] = i;
return 0;
}
/******************************************/
/* decoding */
@ -767,14 +527,9 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
s->mb_intra = 1;
if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
for (i = 0; i < 6; i++)
mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
} else {
for (i = 0; i < mb_block_count; i++)
if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
return ret;
}
} else {
for (i = 0; i < 6; i++) {
ret = ff_mpeg1_decode_block_intra(&s->gb,
@ -994,15 +749,6 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
}
if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
for (i = 0; i < 6; i++) {
if (cbp & 32)
mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
else
s->block_last_index[i] = -1;
cbp += cbp;
}
} else {
cbp <<= 12 - mb_block_count;
for (i = 0; i < mb_block_count; i++) {
@ -1014,17 +760,7 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
}
cbp += cbp;
}
}
} else {
if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
for (i = 0; i < 6; i++) {
if (cbp & 32)
mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
else
s->block_last_index[i] = -1;
cbp += cbp;
}
} else {
for (i = 0; i < 6; i++) {
if (cbp & 32) {
if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
@ -1034,7 +770,6 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
}
cbp += cbp;
}
}
}
} else {
for (i = 0; i < 12; i++)