MIME Types and File Extensions

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STATUS: final editing before being turned into an official Xiph recommendation and work on rfcs will start to reflect these policies

DISCLAIMER: currently, only application/ogg is a registered mimetype. Registration for the others will need to be undertaken. In the meantime, use of the "x-" mimetype is recommended.

IMPLEMENTATION recommendations and patches: see MIME-Migration.

Contents

.ogx - application/ogg

  • Ogg Multiplex Profile (anything in Ogg)
  • can contain any logical bitstreams multiplexed together in an ogg container
  • will replace the .ogg extension from RFC 3534 http://www.ietf.org/rfc/rfc3534.txt
  • random multitrack files SHOULD contain a Skeleton track to identify all containing logical bitstreams
  • apps that identify a logical bitstream which they cannot decode SHOULD ignore it but MAY still decode the ones they can
  • thus, e.g. an annodex file can gracefully degrade to .ogx if an app cannot decode CMML and/or Skeleton

.oga - audio/ogg

  • Ogg Audio Profile (audio in Ogg container)
  • apps supporting .oga, .ogv SHOULD support decoding from muxed Ogg streams
  • covers e.g. Vorbis, Speex, FLAC, Ghost, OggPCM inside Ogg, though Ogg Vorbis and Ogg Speex also have special profiles
  • May contain Ogg Skeleton and/or CMML logical bitstreams.

RATIONALE: This distinguishes audio-only files, using any of the Xiph audio codecs, from Ogg Vorbis I files (traditional .ogg) which may not contain more than one logical bitstream.

.ogv - video/ogg

  • Ogg Video Profile (a/v in Ogg container)
  • apps supporting .oga, .ogv SHOULD support decoding from muxed Ogg streams
  • covers e.g. Theora, Theora + Vorbis, Theora + Speex, Theora + FLAC, Dirac + Vorbis, MNG + FLAC, OggUVS inside Ogg
  • This list is not exhaustive (for example, Dirac + FLAC is acceptable too)
  • May contain Ogg Skeleton and/or CMML logical bitstreams.

.ogg - audio/ogg+vorbis

  • Ogg Vorbis I Profile
  • .ogg applies now for Ogg Vorbis I files only
  • .ogg has more recently also been used for Ogg FLAC and for Ogg Theora, too - these uses are deprecated now in favor of .oga and .ogv respectively
  • has been defined in RFC 3534 http://www.ietf.org/rfc/rfc3534.txt for application/ogg, so rfc 3534 will be re-defined

RATIONALE: .ogg has traditionally been used for Ogg Vorbis I files, in particular in HW players, hence it is kept for backwards-compatibility

.spx - audio/ogg+speex

  • Ogg Speex Profile
  • .spx has traditionally been used for Ogg Speex files and should be considered for backwards-compatibility

.flac - application/flac

  • flac in native encapsulation format

.anx - application/annodex

  • Profile for multiplexed Ogg that includes a skeleton track and at least one CMML logical bitstream
  • apps that identify a logical bitstream which they cannot decode SHOULD ignore it but MAY still decode the ones they can
  • apps that come across an annodex file and cannot decode CMML and/or Skeleton, but can deal with the others SHOULD gracefully degrade by ignoring these

.axa - audio/annodex

.axv - video/annodex

  • Profile for video in annodex
  • covers e.g. Theora, Theora + Vorbis, Theora + Speex, Theora + FLAC, Dirac + Vorbis, MNG + FLAC, OggUVS inside Ogg with Skeleton and CMML

.xspf - application/xspf+xml

  • Profile for XSPF
  • Cover XSPF, while being used through XML
  • Currently, does not cover JSPF, which is XSPF but on Json

Codec MIME types

Codecs need their own MIME types for streaming and to be used in multitrack ogg files using skeleton:

  • audio/vorbis for Vorbis without container
  • video/theora for Theora without container
  • audio/speex for Speex without container
  • audio/flac for FLAC without container, but extra FLAC Ogg header (?)
  • text/cmml for CMML without container
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