[theora-dev] Re: Ogg Internet Drafts - create application/ogg-vorbis, application/ogg-tarkin, etc.

Silvia.Pfeiffer at csiro.au Silvia.Pfeiffer at csiro.au
Thu Jan 2 02:47:44 PST 2003

Dear David,

I hope it's ok to forward your email to the developer lists. I have not
seen a comprehensive scheme for MIME type naming and file extensions for
ogg files yet - please anybody put me in the picture if there is.

However, I have seen application/x-ogg used for ogg-vorbis files, which
is according to MIME type registration rules an unregistered and
experimental MIME type (see RFC2048) and seems to have worked so far for
ogg-based files. I understand your issues on having application/ogg as
an all-encompassing MIME type, as ogg by itself cannot determine the
further type of content included. Therefore your idea about having more
specific MIME types makes sense.

Yet, I don't believe that application/ogg-tarkin or
application/ogg-vorbis should be chosen, as "application/" to me flags
that the content of the file can only be determined by an application
that can read this specific type of file. In my opinion, vorbis should
be audio/ogg-vorbis because vorbis itself is an encoding format that
makes sense in containers only, such as ogg or rtp. Tarkin on the other
hand is a combination of vorbis and VP3 plus a media mapping onto ogg
such that video/tarkin might make sense, though would not be logical to
the outside world. 

As for file extensions - I've seen theora files also end in .ogg .



<p>David Wheeler wrote:
> Thanks SO MUCH for creating Internet Drafts;
> I cannot begin to tell you how important
> it would be to create IETF RFCs for Ogg and Vorbis (and Tarkin, etc.).
> However, I believe there should NOT be a _single_ MIME type for ogg.
> After all, it may contain different codecs, and different application
> programs may only handle certain codecs.  I believe the MIME type
> should identify the codec as well as the fact that it's ogg.
> For example, many people have _separate_ applications for audio-only
> instead of audio+video.  It would be better if they could start the
> "right" application using just the MIME type information (instead of
> awkward two-stage start-ups that are different than anything else).
> At the least, I suspect there is a need to have different MIME types
> for audio-only vs. video.
> Also, not all applications can handle all codecs, even if they handle
> that kind of media; that would be ESPECIALLY true if Ogg supports multiple
> codecs... which it does.
> Thus, I believe the MIME type should identify both Ogg & the codec.
> Perhaps an application/ogg-vorbis, application/ogg-tarkin, etc.
> You could also register application/ogg (to be used when a more specific
> MIME type isn't available).  Ideally the standard filename extensions
> should be different too; Ogg Vorbis could be ".ogg" since that's become
> so common, Ogg Tarkin could be ".ogt", etc.
> Thanks.
> --- David A. Wheeler
>      dwheeler at ida.org
--- >8 ----
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