Fix -lowres with ffplay.

Patch by Anatoly Nenashev, anatoly d nenashev a ovsoft d ru

Originally committed as revision 26057 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/utils.c

@@ -185,8 +185,9 @@ void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height, int l
 
     *width = FFALIGN(*width , w_align);
     *height= FFALIGN(*height, h_align);
-    if(s->codec_id == CODEC_ID_H264)
+    if(s->codec_id == CODEC_ID_H264 || s->lowres)
         *height+=2; // some of the optimized chroma MC reads one line too much
+                    // which is also done in mpeg decoders with lowres > 0
 
     linesize_align[0] =
     linesize_align[1] =