another try at decode_ref_pic_list_reordering()

Originally committed as revision 4245 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -3305,31 +3305,36 @@ static int decode_ref_pic_list_reordering(H264Context *h){
                         else                                pred+= abs_diff_pic_num;
                         pred &= h->max_pic_num - 1;
                     
-                        for(i= h->ref_count[list]-1; i>=0; i--){
-                            if(h->ref_list[list][i].data[0] != NULL && h->ref_list[list][i].pic_id == pred && h->ref_list[list][i].long_ref==0) // ignore non existing pictures by testing data[0] pointer
+                        for(i= h->short_ref_count-1; i>=0; i--){
+                            ref = h->short_ref[i];
+                            assert(ref->reference == 3);
+                            assert(!ref->long_ref);
+                            if(ref->data[0] != NULL && ref->frame_num == pred && ref->long_ref == 0) // ignore non existing pictures by testing data[0] pointer
                                 break;
                         }
+                        if(i>=0)
+                            ref->pic_id= ref->frame_num;
                     }else{
                         pic_id= get_ue_golomb(&s->gb); //long_term_pic_idx
-
-                        for(i= h->ref_count[list]-1; i>=0; i--){
-                            if(h->ref_list[list][i].pic_id == pic_id && h->ref_list[list][i].long_ref==1) // no need to ignore non existing pictures as non existing pictures have long_ref==0
-                                break;
-                        }
+                        ref = h->long_ref[pic_id];
+                        ref->pic_id= pic_id;
+                        assert(ref->reference == 3);
+                        assert(ref->long_ref);
+                        i=0;
                     }
 
                     if (i < 0) {
                         av_log(h->s.avctx, AV_LOG_ERROR, "reference picture missing during reorder\n");
                         memset(&h->ref_list[list][index], 0, sizeof(Picture)); //FIXME
-                    } else if (i != index) /* this test is not necessary, it is only an optimisation to skip double copy of Picture structure in this case */ {
-                        Picture tmp= h->ref_list[list][i];
-                        if (i < index) {
-                            i = h->ref_count[list];
+                    } else {
+                        for(i=index; i+1<h->ref_count[list]; i++){
+                            if(ref->long_ref == h->ref_list[list][i].long_ref && ref->pic_id == h->ref_list[list][i].pic_id)
+                                break;
                         }
                         for(; i > index; i--){
                             h->ref_list[list][i]= h->ref_list[list][i-1];
                         }
-                        h->ref_list[list][index]= tmp;
+                        h->ref_list[list][index]= *ref;
                     }
                 }else{
                     av_log(h->s.avctx, AV_LOG_ERROR, "illegal reordering_of_pic_nums_idc\n");