h261, h263 decoders: convert to RL_VLC.

Some additional optimizations in following patch.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

4 files changed, 60 insertions, 38 deletions

diff --git a/libavcodec/flv.h b/libavcodec/flv.h
index 16bc88b663..df508203b3 100644
--- a/libavcodec/flv.h
+++ b/libavcodec/flv.h
@@ -28,6 +28,5 @@ void ff_flv_encode_picture_header(MpegEncContext * s, int picture_number);
 void ff_flv2_encode_ac_esc(PutBitContext *pb, int slevel, int level, int run, int last);
 
 int ff_flv_decode_picture_header(MpegEncContext *s);
-void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last);
 
 #endif /* AVCODEC_FLV_H */
diff --git a/libavcodec/flvdec.c b/libavcodec/flvdec.c
index 3b048f666d..db413f21f2 100644
--- a/libavcodec/flvdec.c
+++ b/libavcodec/flvdec.c
@@ -22,18 +22,6 @@
 #include "flv.h"
 #include "libavutil/imgutils.h"
 
-void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last)
-{
-    int is11 = get_bits1(gb);
-    *last = get_bits1(gb);
-    *run  = get_bits(gb, 6);
-    if (is11) {
-        *level = get_sbits(gb, 11);
-    } else {
-        *level = get_sbits(gb, 7);
-    }
-}
-
 int ff_flv_decode_picture_header(MpegEncContext *s)
 {
     int format, width, height;
diff --git a/libavcodec/h261dec.c b/libavcodec/h261dec.c
index 301ecc111f..5f0eb59e3c 100644
--- a/libavcodec/h261dec.c
+++ b/libavcodec/h261dec.c
@@ -258,7 +258,7 @@ static int decode_mv_component(GetBitContext *gb, int v)
 static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
 {
     MpegEncContext *const s = &h->s;
-    int code, level, i, j, run;
+    int level, i, j, run;
     RLTable *rl = &ff_h261_rl_tcoeff;
     const uint8_t *scan_table;
 
@@ -303,27 +303,32 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
         s->block_last_index[n] = i - 1;
         return 0;
     }
+    {
+    OPEN_READER(re, &s->gb);
     for (;;) {
-        code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2);
-        if (code < 0) {
+        UPDATE_CACHE(re, &s->gb);
+        GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TCOEFF_VLC_BITS, 2, 0);
+        if (run == 66 && level) {
             av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
                    s->mb_x, s->mb_y);
             return -1;
         }
-        if (code == rl->n) {
+        if (run == 66) {
             /* escape */
             /* The remaining combinations of (run, level) are encoded with a
              * 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
              * level. */
-            run   = get_bits(&s->gb, 6);
-            level = get_sbits(&s->gb, 8);
-        } else if (code == 0) {
+            run   = SHOW_UBITS(re, &s->gb, 6);
+            SKIP_CACHE(re, &s->gb, 6);
+            level = SHOW_SBITS(re, &s->gb, 8);
+            SKIP_COUNTER(re, &s->gb, 6 + 8);
+        } else if (level == 0) {
             break;
         } else {
-            run   = rl->table_run[code];
-            level = rl->table_level[code];
-            if (get_bits1(&s->gb))
+            run--;
+            if (SHOW_UBITS(re, &s->gb, 1))
                 level = -level;
+            SKIP_COUNTER(re, &s->gb, 1);
         }
         i += run;
         if (i >= 64) {
@@ -335,6 +340,8 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
         block[j] = level;
         i++;
     }
+    CLOSE_READER(re, &s->gb);
+    }
     s->block_last_index[n] = i - 1;
     return 0;
 }
diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
index e64c2bb769..c481621fd2 100644
--- a/libavcodec/ituh263dec.c
+++ b/libavcodec/ituh263dec.c
@@ -418,7 +418,7 @@ static void h263_decode_dquant(MpegEncContext *s){
 static int h263_decode_block(MpegEncContext * s, int16_t * block,
                              int n, int coded)
 {
-    int code, level, i, j, last, run;
+    int level, i, j, last, run;
     RLTable *rl = &ff_h263_rl_inter;
     const uint8_t *scan_table;
     GetBitContext gb= s->gb;
@@ -479,40 +479,66 @@ static int h263_decode_block(MpegEncContext * s, int16_t * block,
         return 0;
     }
 retry:
+    {
+    OPEN_READER(re, &s->gb);
     for(;;) {
-        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
-        if (code < 0){
+        UPDATE_CACHE(re, &s->gb);
+        GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
+        if (run == 66 && level){
             av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
             return -1;
         }
-        if (code == rl->n) {
+        if (run == 66) {
             /* escape */
             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
-                ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
+                int is11 = SHOW_UBITS(re, &s->gb, 1);
+                SKIP_CACHE(re, &s->gb, 1);
+                last = SHOW_UBITS(re, &s->gb, 1);
+                SKIP_CACHE(re, &s->gb, 1);
+                run = SHOW_UBITS(re, &s->gb, 6);
+                if (is11) {
+                    SKIP_COUNTER(re, &s->gb, 6);
+                    UPDATE_CACHE(re, &s->gb);
+                    level = SHOW_SBITS(re, &s->gb, 11);
+                    SKIP_COUNTER(re, &s->gb, 1 + 1 + 6 + 11);
+                } else {
+                    SKIP_CACHE(re, &s->gb, 6);
+                    level = SHOW_SBITS(re, &s->gb, 7);
+                    SKIP_COUNTER(re, &s->gb, 1 + 1 + 6 + 7);
+                }
             } else {
-                last = get_bits1(&s->gb);
-                run = get_bits(&s->gb, 6);
-                level = (int8_t)get_bits(&s->gb, 8);
+                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 = (int8_t)SHOW_UBITS(re, &s->gb, 8);
+                SKIP_COUNTER(re, &s->gb, 1 + 6 + 8);
                 if(level == -128){
+                    UPDATE_CACHE(re, &s->gb);
                     if (s->codec_id == AV_CODEC_ID_RV10) {
                         /* XXX: should patch encoder too */
-                        level = get_sbits(&s->gb, 12);
+                        level = SHOW_SBITS(re, &s->gb, 12);
+                        SKIP_COUNTER(re, &s->gb, 12);
                     }else{
-                        level = get_bits(&s->gb, 5);
-                        level |= get_sbits(&s->gb, 6)<<5;
+                        level = SHOW_UBITS(re, &s->gb, 5);
+                        SKIP_CACHE(re, &s->gb, 5);
+                        level |= SHOW_SBITS(re, &s->gb, 6)<<5;
+                        SKIP_COUNTER(re, &s->gb, 5 + 6);
                     }
                 }
             }
         } else {
-            run = rl->table_run[code];
-            level = rl->table_level[code];
-            last = code >= rl->last;
-            if (get_bits1(&s->gb))
+            run--;
+            last = run >= 192;
+            run &= 63;
+            if (SHOW_UBITS(re, &s->gb, 1))
                 level = -level;
+            SKIP_COUNTER(re, &s->gb, 1);
         }
         i += run;
         if (i >= 64){
             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
+                CLOSE_READER(re, &s->gb);
                 //Looks like a hack but no, it's the way it is supposed to work ...
                 rl = &ff_rl_intra_aic;
                 i = 0;
@@ -529,6 +555,8 @@ retry:
             break;
         i++;
     }
+    CLOSE_READER(re, &s->gb);
+    }
 not_coded:
     if (s->mb_intra && s->h263_aic) {
         ff_h263_pred_acdc(s, block, n);