sig
  type video =
      [ `A64_multi
      | `A64_multi5
      | `Aasc
      | `Aic
      | `Alias_pix
      | `Amv
      | `Anm
      | `Ansi
      | `Apng
      | `Asv1
      | `Asv2
      | `Aura
      | `Aura2
      | `Av1
      | `Avrn
      | `Avrp
      | `Avs
      | `Avui
      | `Ayuv
      | `Bethsoftvid
      | `Bfi
      | `Binkvideo
      | `Bitpacked
      | `Bmp
      | `Bmv_video
      | `Brender_pix
      | `C93
      | `Cavs
      | `Cdgraphics
      | `Cdxl
      | `Cfhd
      | `Cinepak
      | `Clearvideo
      | `Cljr
      | `Cllc
      | `Cmv
      | `Cpia
      | `Cscd
      | `Cyuv
      | `Daala
      | `Dds
      | `Dfa
      | `Dirac
      | `Dnxhd
      | `Dpx
      | `Dsicinvideo
      | `Dvvideo
      | `Dxa
      | `Dxtory
      | `Dxv
      | `Escape124
      | `Escape130
      | `Exr
      | `Ffv1
      | `Ffvhuff
      | `Fic
      | `Fits
      | `Flashsv
      | `Flashsv2
      | `Flic
      | `Flv1
      | `Fmvc
      | `Fraps
      | `Frwu
      | `G2m
      | `Gdv
      | `Gif
      | `H261
      | `H263
      | `H263i
      | `H263p
      | `H264
      | `Hap
      | `Hevc
      | `Hnm4_video
      | `Hq_hqa
      | `Hqx
      | `Huffyuv
      | `Idcin
      | `Iff_ilbm
      | `Indeo2
      | `Indeo3
      | `Indeo4
      | `Indeo5
      | `Interplay_video
      | `Jpeg2000
      | `Jpegls
      | `Jv
      | `Kgv1
      | `Kmvc
      | `Lagarith
      | `Ljpeg
      | `Loco
      | `M101
      | `Mad
      | `Magicyuv
      | `Mdec
      | `Mimic
      | `Mjpeg
      | `Mjpegb
      | `Mmvideo
      | `Motionpixels
      | `Mpeg1video
      | `Mpeg2video
      | `Mpeg4
      | `Msa1
      | `Mscc
      | `Msmpeg4v1
      | `Msmpeg4v2
      | `Msmpeg4v3
      | `Msrle
      | `Mss1
      | `Mss2
      | `Msvideo1
      | `Mszh
      | `Mts2
      | `Mvc1
      | `Mvc2
      | `Mxpeg
      | `Nuv
      | `Paf_video
      | `Pam
      | `Pbm
      | `Pcx
      | `Pgm
      | `Pgmyuv
      | `Pictor
      | `Pixlet
      | `Png
      | `Ppm
      | `Prores
      | `Psd
      | `Ptx
      | `Qdraw
      | `Qpeg
      | `Qtrle
      | `R10k
      | `R210
      | `Rawvideo
      | `Rl2
      | `Roq
      | `Rpza
      | `Rscc
      | `Rv10
      | `Rv20
      | `Rv30
      | `Rv40
      | `Sanm
      | `Scpr
      | `Screenpresso
      | `Sgi
      | `Sgirle
      | `Sheervideo
      | `Smackvideo
      | `Smc
      | `Smvjpeg
      | `Snow
      | `Sp5x
      | `Speedhq
      | `Srgc
      | `Sunrast
      | `Svg
      | `Svq1
      | `Svq3
      | `Targa
      | `Targa_y216
      | `Tdsc
      | `Tgq
      | `Tgv
      | `Theora
      | `Thp
      | `Tiertexseqvideo
      | `Tiff
      | `Tmv
      | `Tqi
      | `Truemotion1
      | `Truemotion2
      | `Truemotion2rt
      | `Tscc
      | `Tscc2
      | `Txd
      | `Ulti
      | `Utvideo
      | `V210
      | `V210x
      | `V308
      | `V408
      | `V410
      | `Vb
      | `Vble
      | `Vc1
      | `Vc1image
      | `Vcr1
      | `Vixl
      | `Vmdvideo
      | `Vmnc
      | `Vp3
      | `Vp5
      | `Vp6
      | `Vp6a
      | `Vp6f
      | `Vp7
      | `Vp8
      | `Vp9
      | `Webp
      | `Wmv1
      | `Wmv2
      | `Wmv3
      | `Wmv3image
      | `Wnv1
      | `Ws_vqa
      | `Xan_wc3
      | `Xan_wc4
      | `Xbm
      | `Xface
      | `Xpm
      | `Xwd
      | `Y41p
      | `Ylc
      | `Yop
      | `Yuv4
      | `Zerocodec
      | `Zlib
      | `Zmbv
      | `_012v
      | `_4xm
      | `_8bps ]
  type audio =
      [ `Aac
      | `Aac_latm
      | `Ac3
      | `Adpcm_4xm
      | `Adpcm_adx
      | `Adpcm_afc
      | `Adpcm_aica
      | `Adpcm_ct
      | `Adpcm_dtk
      | `Adpcm_ea
      | `Adpcm_ea_maxis_xa
      | `Adpcm_ea_r1
      | `Adpcm_ea_r2
      | `Adpcm_ea_r3
      | `Adpcm_ea_xas
      | `Adpcm_g722
      | `Adpcm_g726
      | `Adpcm_g726le
      | `Adpcm_ima_amv
      | `Adpcm_ima_apc
      | `Adpcm_ima_dat4
      | `Adpcm_ima_dk3
      | `Adpcm_ima_dk4
      | `Adpcm_ima_ea_eacs
      | `Adpcm_ima_ea_sead
      | `Adpcm_ima_iss
      | `Adpcm_ima_oki
      | `Adpcm_ima_qt
      | `Adpcm_ima_rad
      | `Adpcm_ima_smjpeg
      | `Adpcm_ima_wav
      | `Adpcm_ima_ws
      | `Adpcm_ms
      | `Adpcm_mtaf
      | `Adpcm_psx
      | `Adpcm_sbpro_2
      | `Adpcm_sbpro_3
      | `Adpcm_sbpro_4
      | `Adpcm_swf
      | `Adpcm_thp
      | `Adpcm_thp_le
      | `Adpcm_vima
      | `Adpcm_xa
      | `Adpcm_yamaha
      | `Alac
      | `Amr_nb
      | `Amr_wb
      | `Ape
      | `Aptx
      | `Aptx_hd
      | `Atrac1
      | `Atrac3
      | `Atrac3al
      | `Atrac3p
      | `Atrac3pal
      | `Binkaudio_dct
      | `Binkaudio_rdft
      | `Bmv_audio
      | `Celt
      | `Codec2
      | `Comfort_noise
      | `Cook
      | `Dolby_e
      | `Dsd_lsbf
      | `Dsd_lsbf_planar
      | `Dsd_msbf
      | `Dsd_msbf_planar
      | `Dsicinaudio
      | `Dss_sp
      | `Dst
      | `Dts
      | `Dvaudio
      | `Eac3
      | `Evrc
      | `Ffwavesynth
      | `Flac
      | `G723_1
      | `G729
      | `Gremlin_dpcm
      | `Gsm
      | `Gsm_ms
      | `Iac
      | `Ilbc
      | `Imc
      | `Interplay_acm
      | `Interplay_dpcm
      | `Mace3
      | `Mace6
      | `Metasound
      | `Mlp
      | `Mp1
      | `Mp2
      | `Mp3
      | `Mp3adu
      | `Mp3on4
      | `Mp4als
      | `Musepack7
      | `Musepack8
      | `Nellymoser
      | `On2avc
      | `Opus
      | `Paf_audio
      | `Pcm_alaw
      | `Pcm_bluray
      | `Pcm_dvd
      | `Pcm_f16le
      | `Pcm_f24le
      | `Pcm_f32be
      | `Pcm_f32le
      | `Pcm_f64be
      | `Pcm_f64le
      | `Pcm_lxf
      | `Pcm_mulaw
      | `Pcm_s16be
      | `Pcm_s16be_planar
      | `Pcm_s16le
      | `Pcm_s16le_planar
      | `Pcm_s24be
      | `Pcm_s24daud
      | `Pcm_s24le
      | `Pcm_s24le_planar
      | `Pcm_s32be
      | `Pcm_s32le
      | `Pcm_s32le_planar
      | `Pcm_s64be
      | `Pcm_s64le
      | `Pcm_s8
      | `Pcm_s8_planar
      | `Pcm_u16be
      | `Pcm_u16le
      | `Pcm_u24be
      | `Pcm_u24le
      | `Pcm_u32be
      | `Pcm_u32le
      | `Pcm_u8
      | `Pcm_zork
      | `Qcelp
      | `Qdm2
      | `Qdmc
      | `Ra_144
      | `Ra_288
      | `Ralf
      | `Roq_dpcm
      | `S302m
      | `Sbc
      | `Sdx2_dpcm
      | `Shorten
      | `Sipr
      | `Smackaudio
      | `Smv
      | `Sol_dpcm
      | `Sonic
      | `Sonic_ls
      | `Speex
      | `Tak
      | `Truehd
      | `Truespeech
      | `Tta
      | `Twinvq
      | `Vmdaudio
      | `Vorbis
      | `Wavpack
      | `Westwood_snd1
      | `Wmalossless
      | `Wmapro
      | `Wmav1
      | `Wmav2
      | `Wmavoice
      | `Xan_dpcm
      | `Xma1
      | `Xma2
      | `_4gv
      | `_8svx_exp
      | `_8svx_fib ]
  type subtitle =
      [ `Ass
      | `Dvb_subtitle
      | `Dvb_teletext
      | `Dvd_subtitle
      | `Eia_608
      | `Hdmv_pgs_subtitle
      | `Hdmv_text_subtitle
      | `Jacosub
      | `Microdvd
      | `Mov_text
      | `Mpl2
      | `Pjs
      | `Realtext
      | `Sami
      | `Srt
      | `Ssa
      | `Stl
      | `Subrip
      | `Subviewer
      | `Subviewer1
      | `Text
      | `Vplayer
      | `Webvtt
      | `Xsub ]
end