[theora-dev] Re: Ogg Internet Drafts - create application/ogg-vorbis, application/ogg-tarkin, etc.
dan at on2.com
Thu Jan 2 04:31:31 PST 2003
just for the record -- I think you mean video/theora when you mention vorbis+VP3. Vp3 is becoming Theora. Tarkin is another video codec project at Xiph.
As for this whole MIME type issue, can someone enlighten me as to how this problem is addressed with Quicktime, Microsoft, and RealNetworks plug-ins today? Also, does an MPEG4 tag specify which audio codec is used?
thanks - dan
From: Silvia.Pfeiffer at csiro.au [mailto:Silvia.Pfeiffer at csiro.au]
Sent: Thu 1/2/2003 5:47 AM
To: dwheeler at ida.org
Cc: triad at df.lth.se; vorbis-dev at xiph.org; theora-dev at xiph.org
Subject: [theora-dev] Re: Ogg Internet Drafts - create application/ogg-vorbis, application/ogg-tarkin, etc.
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 .
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.
> --- David A. Wheeler
> dwheeler at ida.org
--- >8 ----
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