fix rv20 b frames (broke since r5264 Mon Apr 3 07:52:24 2006 UTC 2x faster ff_mpeg4_set_direct_mv)

Originally committed as revision 6388 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h263.c

@@ -556,7 +556,7 @@ void ff_clean_mpeg4_qscales(MpegEncContext *s){
 #define tab_size ((signed)(sizeof(s->direct_scale_mv[0])/sizeof(int16_t)))
 #define tab_bias (tab_size/2)
 
-static void ff_mpeg4_init_direct_mv(MpegEncContext *s){
+void ff_mpeg4_init_direct_mv(MpegEncContext *s){
     int i;
     for(i=0; i<tab_size; i++){
         s->direct_scale_mv[0][i] = (i-tab_bias)*s->pb_time/s->pp_time;

libavcodec/rv10.c

@@ -473,6 +473,7 @@ static int rv20_decode_picture_header(MpegEncContext *s)
                 av_log(s->avctx, AV_LOG_DEBUG, "messed up order, possible from seeking? skipping current b frame\n");
                 return FRAME_SKIPPED;
             }
+            ff_mpeg4_init_direct_mv(s);
         }
     }
 //    printf("%d %d %d %d %d\n", seq, (int)s->time, (int)s->last_non_b_time, s->pp_time, s->pb_time);