UNKNOWN          2771 fftools/ffmpeg_opt.c     enum { PAL, NTSC, FILM, UNKNOWN } norm = UNKNOWN;
UNKNOWN          2802 fftools/ffmpeg_opt.c                 if (norm != UNKNOWN)
UNKNOWN          2806 fftools/ffmpeg_opt.c         if (norm != UNKNOWN)
UNKNOWN          2810 fftools/ffmpeg_opt.c     if (norm == UNKNOWN) {
UNKNOWN           377 libavcodec/vaapi_decode.c     MAP(H263,        UNKNOWN,         H263Baseline),
UNKNOWN           406 libavcodec/vaapi_decode.c     MAP(VP8,         UNKNOWN,       VP8Version0_3 ),
UNKNOWN           394 libavformat/rtspdec.c         *methodcode = UNKNOWN;
UNKNOWN            54 libavutil/error.c     { ERROR_TAG(UNKNOWN),            "Unknown error occurred"                         },