libavformat/yuv4mpegdec.c:197: error: Uninitialized Value
  The value read from field_order was never initialized.

libavformat/yuv4mpegdec.c:197:5: 
195.     st->sample_aspect_ratio           = (AVRational){ aspectn, aspectd };
196.     st->codec->chroma_sample_location = chroma_sample_location;
197.     st->codec->field_order            = field_order;
         ^
198. 
199.     return 0;
