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VP8: optimized mv prediction and decoding

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Merge find_near_mvs and mv bitstream decoding: don't do prediction steps
until absolutely necessary.
(cherry picked from commit f3d09d44b7)
oldabi
Jason Garrett-Glaser 14 years ago committed by Michael Niedermayer
parent 943dc94265
commit ccba4f4c25
1 changed files with 91 additions and 91 deletions
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  1. 182
      libavcodec/vp8.c

182
libavcodec/vp8.c
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@ -528,68 +528,6 @@ void clamp_mv(VP8Context *s, VP56mv *dst, const VP56mv *src, int mb_x, int mb_y)
((s->mb_height - 1 - mb_y) << 6) + MARGIN);
}
static av_always_inline
void find_near_mvs(VP8Context *s, VP8Macroblock *mb,
VP56mv near[2], VP56mv *best, uint8_t cnt[4])
{
VP8Macroblock *mb_edge[3] = { mb + 2 /* top */,
mb - 1 /* left */,
mb + 1 /* top-left */ };
enum { EDGE_TOP, EDGE_LEFT, EDGE_TOPLEFT };
VP56mv near_mv[4] = {{ 0 }};
enum { CNT_ZERO, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV };
int idx = CNT_ZERO;
int best_idx = CNT_ZERO;
int cur_sign_bias = s->sign_bias[mb->ref_frame];
int *sign_bias = s->sign_bias;
/* Process MB on top, left and top-left */
#define MV_EDGE_CHECK(n)\
{\
VP8Macroblock *edge = mb_edge[n];\
int edge_ref = edge->ref_frame;\
if (edge_ref != VP56_FRAME_CURRENT) {\
uint32_t mv = AV_RN32A(&edge->mv);\
if (mv) {\
if (cur_sign_bias != sign_bias[edge_ref]) {\
/* SWAR negate of the values in mv. */\
mv = ~mv;\
mv = ((mv&0x7fff7fff) + 0x00010001) ^ (mv&0x80008000);\
}\
if (!n || mv != AV_RN32A(&near_mv[idx]))\
AV_WN32A(&near_mv[++idx], mv);\
cnt[idx] += 1 + (n != 2);\
} else\
cnt[CNT_ZERO] += 1 + (n != 2);\
}\
}
MV_EDGE_CHECK(0)
MV_EDGE_CHECK(1)
MV_EDGE_CHECK(2)
/* If we have three distinct MVs, merge first and last if they're the same */
if (cnt[CNT_SPLITMV] && AV_RN32A(&near_mv[1+EDGE_TOP]) == AV_RN32A(&near_mv[1+EDGE_TOPLEFT]))
cnt[CNT_NEAREST] += 1;
cnt[CNT_SPLITMV] = ((mb_edge[EDGE_LEFT]->mode == VP8_MVMODE_SPLIT) +
(mb_edge[EDGE_TOP]->mode == VP8_MVMODE_SPLIT)) * 2 +
(mb_edge[EDGE_TOPLEFT]->mode == VP8_MVMODE_SPLIT);
/* Swap near and nearest if necessary */
if (cnt[CNT_NEAR] > cnt[CNT_NEAREST]) {
FFSWAP(uint8_t, cnt[CNT_NEAREST], cnt[CNT_NEAR]);
FFSWAP( VP56mv, near_mv[CNT_NEAREST], near_mv[CNT_NEAR]);
}
/* Choose the best mv out of 0,0 and the nearest mv */
if (cnt[CNT_NEAREST] >= cnt[CNT_ZERO])
best_idx = CNT_NEAREST;
mb->mv = near_mv[best_idx];
near[0] = near_mv[CNT_NEAREST];
near[1] = near_mv[CNT_NEAR];
}
/**
* Motion vector coding, 17.1.
*/
@ -699,6 +637,96 @@ int decode_splitmvs(VP8Context *s, VP56RangeCoder *c, VP8Macroblock *mb)
return num;
}
static av_always_inline
void decode_mvs(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y)
{
VP8Macroblock *mb_edge[3] = { mb + 2 /* top */,
mb - 1 /* left */,
mb + 1 /* top-left */ };
enum { CNT_ZERO, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV };
enum { EDGE_TOP, EDGE_LEFT, EDGE_TOPLEFT };
int idx = CNT_ZERO;
int cur_sign_bias = s->sign_bias[mb->ref_frame];
int *sign_bias = s->sign_bias;
VP56mv near_mv[4];
uint8_t cnt[4] = { 0 };
VP56RangeCoder *c = &s->c;
AV_ZERO32(&near_mv[0]);
AV_ZERO32(&near_mv[1]);
AV_ZERO32(&near_mv[2]);
/* Process MB on top, left and top-left */
#define MV_EDGE_CHECK(n)\
{\
VP8Macroblock *edge = mb_edge[n];\
int edge_ref = edge->ref_frame;\
if (edge_ref != VP56_FRAME_CURRENT) {\
uint32_t mv = AV_RN32A(&edge->mv);\
if (mv) {\
if (cur_sign_bias != sign_bias[edge_ref]) {\
/* SWAR negate of the values in mv. */\
mv = ~mv;\
mv = ((mv&0x7fff7fff) + 0x00010001) ^ (mv&0x80008000);\
}\
if (!n || mv != AV_RN32A(&near_mv[idx]))\
AV_WN32A(&near_mv[++idx], mv);\
cnt[idx] += 1 + (n != 2);\
} else\
cnt[CNT_ZERO] += 1 + (n != 2);\
}\
}
MV_EDGE_CHECK(0)
MV_EDGE_CHECK(1)
MV_EDGE_CHECK(2)
mb->partitioning = VP8_SPLITMVMODE_NONE;
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_ZERO]][0])) {
mb->mode = VP8_MVMODE_MV;
/* If we have three distinct MVs, merge first and last if they're the same */
if (cnt[CNT_SPLITMV] && AV_RN32A(&near_mv[1+EDGE_TOP]) == AV_RN32A(&near_mv[1+EDGE_TOPLEFT]))
cnt[CNT_NEAREST] += 1;
/* Swap near and nearest if necessary */
if (cnt[CNT_NEAR] > cnt[CNT_NEAREST]) {
FFSWAP(uint8_t, cnt[CNT_NEAREST], cnt[CNT_NEAR]);
FFSWAP( VP56mv, near_mv[CNT_NEAREST], near_mv[CNT_NEAR]);
}
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_NEAREST]][1])) {
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_NEAR]][2])) {
/* Choose the best mv out of 0,0 and the nearest mv */
clamp_mv(s, &mb->mv, &near_mv[CNT_ZERO + (cnt[CNT_NEAREST] >= cnt[CNT_ZERO])], mb_x, mb_y);
cnt[CNT_SPLITMV] = ((mb_edge[EDGE_LEFT]->mode == VP8_MVMODE_SPLIT) +
(mb_edge[EDGE_TOP]->mode == VP8_MVMODE_SPLIT)) * 2 +
(mb_edge[EDGE_TOPLEFT]->mode == VP8_MVMODE_SPLIT);
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_SPLITMV]][3])) {
mb->mode = VP8_MVMODE_SPLIT;
mb->mv = mb->bmv[decode_splitmvs(s, c, mb) - 1];
} else {
mb->mv.y += read_mv_component(c, s->prob->mvc[0]);
mb->mv.x += read_mv_component(c, s->prob->mvc[1]);
mb->bmv[0] = mb->mv;
}
} else {
clamp_mv(s, &mb->mv, &near_mv[CNT_NEAR], mb_x, mb_y);
mb->bmv[0] = mb->mv;
}
} else {
clamp_mv(s, &mb->mv, &near_mv[CNT_NEAREST], mb_x, mb_y);
mb->bmv[0] = mb->mv;
}
} else {
mb->mode = VP8_MVMODE_ZERO;
AV_ZERO32(&mb->mv);
mb->bmv[0] = mb->mv;
}
}
static av_always_inline
void decode_intra4x4_modes(VP8Context *s, VP56RangeCoder *c,
int mb_x, int keyframe)
@ -749,9 +777,6 @@ void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, uint8_
s->chroma_pred_mode = vp8_rac_get_tree(c, vp8_pred8x8c_tree, vp8_pred8x8c_prob_intra);
mb->ref_frame = VP56_FRAME_CURRENT;
} else if (vp56_rac_get_prob_branchy(c, s->prob->intra)) {
VP56mv near[2], best;
uint8_t cnt[4] = { 0 };
// inter MB, 16.2
if (vp56_rac_get_prob_branchy(c, s->prob->last))
mb->ref_frame = vp56_rac_get_prob(c, s->prob->golden) ?
@ -761,32 +786,7 @@ void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, uint8_
s->ref_count[mb->ref_frame-1]++;
// motion vectors, 16.3
find_near_mvs(s, mb, near, &best, cnt);
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[0]][0])) {
mb->mode = VP8_MVMODE_MV;
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[1]][1])) {
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[2]][2])) {
if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[3]][3])) {
mb->mode = VP8_MVMODE_SPLIT;
clamp_mv(s, &mb->mv, &mb->mv, mb_x, mb_y);
mb->mv = mb->bmv[decode_splitmvs(s, c, mb) - 1];
} else {
clamp_mv(s, &mb->mv, &mb->mv, mb_x, mb_y);
mb->mv.y += read_mv_component(c, s->prob->mvc[0]);
mb->mv.x += read_mv_component(c, s->prob->mvc[1]);
}
} else
clamp_mv(s, &mb->mv, &near[1], mb_x, mb_y);
} else
clamp_mv(s, &mb->mv, &near[0], mb_x, mb_y);
} else {
mb->mode = VP8_MVMODE_ZERO;
AV_ZERO32(&mb->mv);
}
if (mb->mode != VP8_MVMODE_SPLIT) {
mb->partitioning = VP8_SPLITMVMODE_NONE;
mb->bmv[0] = mb->mv;
}
decode_mvs(s, mb, mb_x, mb_y);
} else {
// intra MB, 16.1
mb->mode = vp8_rac_get_tree(c, vp8_pred16x16_tree_inter, s->prob->pred16x16);

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