dont randomly disallow intr4v in adaptive quant

  some PSNR/bitrate gain if adaptive quant is used
initalize qscale_table correctly (it was pretty much random since the qp->lambda change)
  this probably has not much effect as the table isnt used currently IIRC

Originally committed as revision 7342 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 16 insertions, 1 deletions

diff --git a/libavcodec/h263.c b/libavcodec/h263.c
index ca8675de5d..af5fa50e67 100644
--- a/libavcodec/h263.c
+++ b/libavcodec/h263.c
@@ -487,12 +487,28 @@ static inline void restore_ac_coeffs(MpegEncContext * s, DCTELEM block[6][64], i
 }
 
 /**
+ * init s->current_picture.qscale_table from s->lambda_table
+ */
+static void ff_init_qscale_tab(MpegEncContext *s){
+    int8_t * const qscale_table= s->current_picture.qscale_table;
+    int i;
+
+    for(i=0; i<s->mb_num; i++){
+        unsigned int lam= s->lambda_table[ s->mb_index2xy[i] ];
+        int qp= (lam*139 + FF_LAMBDA_SCALE*64) >> (FF_LAMBDA_SHIFT + 7);
+        qscale_table[ s->mb_index2xy[i] ]= clip(qp, s->avctx->qmin, s->avctx->qmax);
+    }
+}
+
+/**
  * modify qscale so that encoding is acually possible in h263 (limit difference to -2..2)
  */
 void ff_clean_h263_qscales(MpegEncContext *s){
     int i;
     int8_t * const qscale_table= s->current_picture.qscale_table;
 
+    ff_init_qscale_tab(s);
+
     for(i=1; i<s->mb_num; i++){
         if(qscale_table[ s->mb_index2xy[i] ] - qscale_table[ s->mb_index2xy[i-1] ] >2)
             qscale_table[ s->mb_index2xy[i] ]= qscale_table[ s->mb_index2xy[i-1] ]+2;
@@ -507,7 +523,6 @@ void ff_clean_h263_qscales(MpegEncContext *s){
             int mb_xy= s->mb_index2xy[i];
 
             if(qscale_table[mb_xy] != qscale_table[s->mb_index2xy[i-1]] && (s->mb_type[mb_xy]&CANDIDATE_MB_TYPE_INTER4V)){
-                s->mb_type[mb_xy]&= ~CANDIDATE_MB_TYPE_INTER4V;
                 s->mb_type[mb_xy]|= CANDIDATE_MB_TYPE_INTER;
             }
         }