// https://ffmpeg.org/doxygen/trunk/structAVCodecParserContext.html
/* reads from demuxer because codec frame not ready */
int interlace0 = ffvideo[stream]->st->codecpar->field_order;
// https://ffmpeg.org/doxygen/trunk/structAVCodecParserContext.html
/* reads from demuxer because codec frame not ready */
int interlace0 = ffvideo[stream]->st->codecpar->field_order;