CODEC_FLAG_LOW_DELAY fix

Originally committed as revision 2016 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h263.c

@@ -4648,7 +4648,7 @@ static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
     int time_incr, time_increment;
 
     s->pict_type = get_bits(gb, 2) + I_TYPE;	/* pict type: I = 0 , P = 1 */
-    if(s->pict_type==B_TYPE && s->low_delay && s->vol_control_parameters==0){
+    if(s->pict_type==B_TYPE && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
         printf("low_delay flag set, but shouldnt, clearing it\n");
         s->low_delay=0;
     }

libavcodec/mpeg12.c

@@ -1653,7 +1653,10 @@ static void mpeg_decode_sequence_extension(MpegEncContext *s)
     s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
     skip_bits1(&s->gb); /* marker */
     vbv_buf_ext = get_bits(&s->gb, 8);
+
     s->low_delay = get_bits1(&s->gb);
+    if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
+
     frame_rate_ext_n = get_bits(&s->gb, 2);
     frame_rate_ext_d = get_bits(&s->gb, 5);
     av_reduce(