UNKNOWN          2229 ffmpeg_opt.c       enum { PAL, NTSC, FILM, UNKNOWN } norm = UNKNOWN;
UNKNOWN          2260 ffmpeg_opt.c                   if (norm != UNKNOWN)
UNKNOWN          2264 ffmpeg_opt.c           if (norm != UNKNOWN)
UNKNOWN          2268 ffmpeg_opt.c       if (norm == UNKNOWN) {
UNKNOWN           389 libavformat/rtspdec.c         *methodcode = UNKNOWN;
UNKNOWN            54 libavutil/error.c     { ERROR_TAG(UNKNOWN),            "Unknown error occurred"                         },