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rl vlc decoding optimizations 

Originally committed as revision 748 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-07-13 14:55:12 +00:00
parent 6b765cd276
commit 45a82edbdd
4 changed files with 153 additions and 69 deletions
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29
libavcodec/common.h
View File

@ -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

40
libavcodec/h263.c
View File

@ -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 */

4
libavcodec/mpegvideo.h
View File

@ -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);

149
libavcodec/msmpeg4.c
View File

@ -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;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
}
i += run;
if (i >= 64){
fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
return -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;
}
block[scan_table[i]] = level;
break;
}
j = scan_table[i];
block[j] = level;
i++;
if (last)
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;
}