MKTAG 285 3rdparty/include/ffmpeg_/libavutil/common.h #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24)) MKTAG 87 modules/videoio/src/ffmpeg_codecs.hpp #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))