From 15c5fa7b7f63c81e6c7cd987ab10d9bc8b1fb557 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Fri, 24 Sep 2004 20:35:59 +0000
Subject: [PATCH] trellis quantization for h263(p)

Originally committed as revision 3503 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/h263.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/libavcodec/h263.c b/libavcodec/h263.c
index f7421ca0c6..922cb1f3b4 100644
--- a/libavcodec/h263.c
+++ b/libavcodec/h263.c
@@ -91,6 +91,8 @@ static uint32_t uni_mpeg4_intra_rl_bits[64*64*2*2];
 static uint8_t  uni_mpeg4_intra_rl_len [64*64*2*2];
 static uint32_t uni_mpeg4_inter_rl_bits[64*64*2*2];
 static uint8_t  uni_mpeg4_inter_rl_len [64*64*2*2];
+static uint8_t  uni_h263_intra_aic_rl_len [64*64*2*2];
+static uint8_t  uni_h263_inter_rl_len [64*64*2*2];
 //#define UNI_MPEG4_ENC_INDEX(last,run,level) ((last)*128 + (run)*256 + (level))
 //#define UNI_MPEG4_ENC_INDEX(last,run,level) ((last)*128*64 + (run) + (level)*64)
 #define UNI_MPEG4_ENC_INDEX(last,run,level) ((last)*128*64 + (run)*128 + (level))
@@ -1876,6 +1878,50 @@ static void init_uni_mpeg4_rl_tab(RLTable *rl, uint32_t *bits_tab, uint8_t *len_
     }
 }
 
+static void init_uni_h263_rl_tab(RLTable *rl, uint32_t *bits_tab, uint8_t *len_tab){
+    int slevel, run, last;
+    
+    assert(MAX_LEVEL >= 64);
+    assert(MAX_RUN   >= 63);
+
+    for(slevel=-64; slevel<64; slevel++){
+        if(slevel==0) continue;
+        for(run=0; run<64; run++){
+            for(last=0; last<=1; last++){
+                const int index= UNI_MPEG4_ENC_INDEX(last, run, slevel+64);
+                int level= slevel < 0 ? -slevel : slevel;
+                int sign= slevel < 0 ? 1 : 0;
+                int bits, len, code;
+                int level1, run1;
+                
+                len_tab[index]= 100;
+                     
+                /* ESC0 */
+                code= get_rl_index(rl, last, run, level);
+                bits= rl->table_vlc[code][0];
+                len=  rl->table_vlc[code][1];
+                bits=bits*2+sign; len++;
+                
+                if(code!=rl->n && len < len_tab[index]){
+                    if(bits_tab) bits_tab[index]= bits;
+                    len_tab [index]= len;
+                }
+                /* ESC */
+                bits= rl->table_vlc[rl->n][0];
+                len = rl->table_vlc[rl->n][1];
+                bits=bits*2+last; len++;
+                bits=bits*64+run; len+=6;
+                bits=bits*256+(level&0xff); len+=8;
+                
+                if(len < len_tab[index]){
+                    if(bits_tab) bits_tab[index]= bits;
+                    len_tab [index]= len;
+                }
+            }
+        }
+    }
+}
+
 void h263_encode_init(MpegEncContext *s)
 {
     static int done = 0;
@@ -1892,10 +1938,21 @@ void h263_encode_init(MpegEncContext *s)
         init_uni_mpeg4_rl_tab(&rl_intra, uni_mpeg4_intra_rl_bits, uni_mpeg4_intra_rl_len);
         init_uni_mpeg4_rl_tab(&rl_inter, uni_mpeg4_inter_rl_bits, uni_mpeg4_inter_rl_len);
 
+        init_uni_h263_rl_tab(&rl_intra_aic, NULL, uni_h263_intra_aic_rl_len);
+        init_uni_h263_rl_tab(&rl_inter    , NULL, uni_h263_inter_rl_len);
+
         init_mv_penalty_and_fcode(s);
     }
     s->me.mv_penalty= mv_penalty; //FIXME exact table for msmpeg4 & h263p
     
+    s->intra_ac_vlc_length     =s->inter_ac_vlc_length     = uni_h263_inter_rl_len;
+    s->intra_ac_vlc_last_length=s->inter_ac_vlc_last_length= uni_h263_inter_rl_len + 128*64;
+    if(s->h263_aic){
+        s->intra_ac_vlc_length     = uni_h263_intra_aic_rl_len;
+        s->intra_ac_vlc_last_length= uni_h263_intra_aic_rl_len + 128*64;
+    }
+    s->ac_esc_length= 7+1+6+8;
+
     // use fcodes >1 only for mpeg4 & h263 & h263p FIXME
     switch(s->codec_id){
     case CODEC_ID_MPEG4: