[SCM] libav/experimental: rl vlc decoding optimizations
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Jun 30 15:32:43 UTC 2013
The following commit has been merged in the experimental branch:
commit 45a82edbdd041c264521600d5c8195d279c0211e
Author: Michael Niedermayer <michaelni at gmx.at>
Date: Sat Jul 13 14:55:12 2002 +0000
rl vlc decoding optimizations
Originally committed as revision 748 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavcodec/common.h b/libavcodec/common.h
index 13ac069..65bfc51 100644
--- a/libavcodec/common.h
+++ b/libavcodec/common.h
@@ -238,6 +238,12 @@ typedef struct VLC {
int table_size, table_allocated;
} VLC;
+typedef struct RL_VLC_ELEM {
+ int16_t level;
+ int8_t len;
+ uint8_t run;
+} RL_VLC_ELEM;
+
/* used to avoid missaligned exceptions on some archs (alpha, ...) */
#ifdef ARCH_X86
#define unaligned32(a) (*(UINT32*)(a))
@@ -755,6 +761,28 @@ void free_vlc(VLC *vlc);
SKIP_BITS(name, gb, n)\
}
+#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth)\
+{\
+ int n, index, nb_bits;\
+\
+ index= SHOW_UBITS(name, gb, bits);\
+ level = table[index].level;\
+ n = table[index].len;\
+\
+ if(max_depth > 1 && n < 0){\
+ LAST_SKIP_BITS(name, gb, bits)\
+ UPDATE_CACHE(name, gb)\
+\
+ nb_bits = -n;\
+\
+ index= SHOW_UBITS(name, gb, nb_bits) + level;\
+ level = table[index].level;\
+ n = table[index].len;\
+ }\
+ run= table[index].run;\
+ SKIP_BITS(name, gb, n)\
+}
+
// deprecated, dont use get_vlc for new code, use get_vlc2 instead or use GET_VLC directly
static inline int get_vlc(GetBitContext *s, VLC *vlc)
{
@@ -783,6 +811,7 @@ static inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int
return code;
}
+
/* define it to include statistics code (useful only for optimizing
codec efficiency */
//#define STATS
diff --git a/libavcodec/h263.c b/libavcodec/h263.c
index 5ea636b..3daa22b 100644
--- a/libavcodec/h263.c
+++ b/libavcodec/h263.c
@@ -1622,9 +1622,49 @@ void init_rl(RLTable *rl)
void init_vlc_rl(RLTable *rl)
{
+ int i, q;
+
init_vlc(&rl->vlc, 9, rl->n + 1,
&rl->table_vlc[0][1], 4, 2,
&rl->table_vlc[0][0], 4, 2);
+
+
+ for(q=0; q<32; q++){
+ int qmul= q*2;
+ int qadd= (q-1)|1;
+
+ if(q==0){
+ qmul=1;
+ qadd=0;
+ }
+
+ rl->rl_vlc[q]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
+ for(i=0; i<rl->vlc.table_size; i++){
+ int code= rl->vlc.table[i][0];
+ int len = rl->vlc.table[i][1];
+ int level, run;
+
+ if(len==0){ // illegal code
+ run= 65;
+ level= MAX_LEVEL;
+ }else if(len<0){ //more bits needed
+ run= 0;
+ level= code;
+ }else{
+ if(code==rl->n){ //esc
+ run= 65;
+ level= 0;
+ }else{
+ run= rl->table_run [code] + 1;
+ level= rl->table_level[code] * qmul + qadd;
+ if(code >= rl->last) run+=192;
+ }
+ }
+ rl->rl_vlc[q][i].len= len;
+ rl->rl_vlc[q][i].level= level;
+ rl->rl_vlc[q][i].run= run;
+ }
+ }
}
/* init vlcs */
diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
index cce073b..d0dcc7d 100644
--- a/libavcodec/mpegvideo.h
+++ b/libavcodec/mpegvideo.h
@@ -482,7 +482,6 @@ void mpeg1_encode_mb(MpegEncContext *s,
void ff_mpeg1_encode_init(MpegEncContext *s);
/* h263enc.c */
-
typedef struct RLTable {
int n; /* number of entries of table_vlc minus 1 */
int last; /* number of values for last = 0 */
@@ -492,7 +491,8 @@ typedef struct RLTable {
UINT8 *index_run[2]; /* encoding only */
INT8 *max_level[2]; /* encoding & decoding */
INT8 *max_run[2]; /* encoding & decoding */
- VLC vlc; /* decoding only */
+ VLC vlc; /* decoding only deprected FIXME remove*/
+ RL_VLC_ELEM *rl_vlc[32]; /* decoding only */
} RLTable;
void init_rl(RLTable *rl);
diff --git a/libavcodec/msmpeg4.c b/libavcodec/msmpeg4.c
index c53dc0d..7ec550e 100644
--- a/libavcodec/msmpeg4.c
+++ b/libavcodec/msmpeg4.c
@@ -1629,9 +1629,10 @@ printf("%c", s->ac_pred ? 'A' : 'I');
static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
int n, int coded)
{
- int code, level, i, j, last, run, run_diff;
+ int level, i, last, run, run_diff;
int dc_pred_dir;
RLTable *rl;
+ RL_VLC_ELEM *rl_vlc;
const UINT8 *scan_table;
int qmul, qadd;
@@ -1671,7 +1672,7 @@ static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
block[0] = level;
run_diff = 0;
- i = 1;
+ i = 0;
if (!coded) {
goto not_coded;
}
@@ -1684,10 +1685,11 @@ static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
scan_table = s->intra_scantable;
}
set_stat(ST_INTRA_AC);
+ rl_vlc= rl->rl_vlc[0];
} else {
qmul = s->qscale << 1;
qadd = (s->qscale - 1) | 1;
- i = 0;
+ i = -1;
rl = &rl_table[3 + s->rl_table_index];
if(s->msmpeg4_version==2)
@@ -1696,53 +1698,66 @@ static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
run_diff = 1;
if (!coded) {
- s->block_last_index[n] = i - 1;
+ s->block_last_index[n] = i;
return 0;
}
scan_table = s->inter_scantable;
set_stat(ST_INTER_AC);
+ rl_vlc= rl->rl_vlc[s->qscale];
}
-
+ {
+ OPEN_READER(re, &s->gb);
for(;;) {
- code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
- if (code < 0){
- fprintf(stderr, "illegal AC-VLC code at %d %d\n", s->mb_x, s->mb_y);
- return -1;
- }
- if (code == rl->n) {
+ UPDATE_CACHE(re, &s->gb);
+ GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2);
+ if (level==0) {
+ int cache;
+ cache= GET_CACHE(re, &s->gb);
/* escape */
- if (s->msmpeg4_version==1 || get_bits1(&s->gb) == 0) {
- if (s->msmpeg4_version==1 || get_bits1(&s->gb) == 0) {
+ if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
+ if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
/* third escape */
+ if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
+ UPDATE_CACHE(re, &s->gb);
if(s->msmpeg4_version<=3){
- last= get_bits1(&s->gb);
- run= get_bits(&s->gb, 6);
- level= get_bits(&s->gb, 8);
- level= ((int8_t)level);
- }else{
+ last= SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
+ run= SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
+ level= SHOW_SBITS(re, &s->gb, 8); LAST_SKIP_CACHE(re, &s->gb, 8);
+ SKIP_COUNTER(re, &s->gb, 1+6+8);
+ }else{
int sign;
- last= get_bits1(&s->gb);
+ last= SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
if(!s->esc3_level_length){
int ll;
//printf("ESC-3 %X at %d %d\n", show_bits(&s->gb, 24), s->mb_x, s->mb_y);
if(s->qscale<8){
- ll= get_bits(&s->gb, 3);
+ ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
if(ll==0){
- if(get_bits1(&s->gb)) printf("cool a new vlc code ,contact the ffmpeg developers and upload the file\n");
+ if(SHOW_UBITS(re, &s->gb, 1)) printf("cool a new vlc code ,contact the ffmpeg developers and upload the file\n");
+ SKIP_BITS(re, &s->gb, 1);
ll=8;
}
}else{
ll=2;
- while(ll<8 && get_bits1(&s->gb)==0) ll++;
+ while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
+ ll++;
+ SKIP_BITS(re, &s->gb, 1);
+ }
+ SKIP_BITS(re, &s->gb, 1);
}
s->esc3_level_length= ll;
- s->esc3_run_length= get_bits(&s->gb, 2) + 3;
+ s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
//printf("level length:%d, run length: %d\n", ll, s->esc3_run_length);
}
- run= get_bits(&s->gb, s->esc3_run_length);
- sign= get_bits1(&s->gb);
- level= get_bits(&s->gb, s->esc3_level_length);
+ run= SHOW_UBITS(re, &s->gb, s->esc3_run_length);
+ SKIP_BITS(re, &s->gb, s->esc3_run_length);
+
+ sign= SHOW_UBITS(re, &s->gb, 1);
+ SKIP_BITS(re, &s->gb, 1);
+
+ level= SHOW_UBITS(re, &s->gb, s->esc3_level_length);
+ SKIP_BITS(re, &s->gb, s->esc3_level_length);
if(sign) level= -level;
}
//printf("level: %d, run: %d at %d %d\n", level, run, s->mb_x, s->mb_y);
@@ -1775,64 +1790,64 @@ static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
return DECODING_AC_LOST;
}
#endif
+ i+= run + 1;
+ if(last) i+=192;
} else {
/* second escape */
- code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
- if (code < 0 || code >= rl->n){
- fprintf(stderr, "illegal ESC2-VLC code %d at %d %d\n", code, s->mb_x, s->mb_y);
- return -1;
- }
- run = rl->table_run[code];
- level = rl->table_level[code];
- last = code >= rl->last;
- run += rl->max_run[last][level] + run_diff;
- level= level * qmul + qadd;
- if (get_bits1(&s->gb))
- level = -level;
+#if MIN_CACHE_BITS < 23
+ LAST_SKIP_BITS(re, &s->gb, 2);
+ UPDATE_CACHE(re, &s->gb);
+#else
+ SKIP_BITS(re, &s->gb, 2);
+#endif
+ GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2);
+ i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
+ level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
+ LAST_SKIP_BITS(re, &s->gb, 1);
}
} else {
/* first escape */
- code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
- if (code < 0 || code >= rl->n){
- fprintf(stderr, "illegal ESC2-VLC code %d at %d %d\n", code, s->mb_x, s->mb_y);
- return -1;
- }
- run = rl->table_run[code];
- level = rl->table_level[code];
- last = code >= rl->last;
- level += rl->max_level[last][run];
- level= level * qmul + qadd;
- if (get_bits1(&s->gb))
- level = -level;
+#if MIN_CACHE_BITS < 22
+ LAST_SKIP_BITS(re, &s->gb, 1);
+ UPDATE_CACHE(re, &s->gb);
+#else
+ SKIP_BITS(re, &s->gb, 1);
+#endif
+ GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2);
+ i+= run;
+ level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
+ level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
+ LAST_SKIP_BITS(re, &s->gb, 1);
}
} else {
- run = rl->table_run[code];
- level = rl->table_level[code] * qmul + qadd;
- last = code >= rl->last;
- if (get_bits1(&s->gb))
- level = -level;
- }
- i += run;
- if (i >= 64){
- fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
- return -1;
+ i+= run;
+ level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
+ LAST_SKIP_BITS(re, &s->gb, 1);
}
+ if (i > 62){
+ i-= 192;
+ if(i&(~63)){
+ fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
+ return -1;
+ }
- j = scan_table[i];
- block[j] = level;
- i++;
- if (last)
+ block[scan_table[i]] = level;
break;
+ }
+
+ block[scan_table[i]] = level;
}
+ CLOSE_READER(re, &s->gb);
+ }
not_coded:
if (s->mb_intra) {
mpeg4_pred_ac(s, block, n, dc_pred_dir);
if (s->ac_pred) {
- i = 64; /* XXX: not optimal */
+ i = 63; /* XXX: not optimal */
}
}
- if(s->msmpeg4_version==4 && i>1) i=64; //FIXME/XXX optimize
- s->block_last_index[n] = i - 1;
+ if(s->msmpeg4_version==4 && i>0) i=63; //FIXME/XXX optimize
+ s->block_last_index[n] = i;
return 0;
}
--
Libav/FFmpeg packaging
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