Re(2): [vorbis-dev] Mime Type and Ogg (More)

[Ali Abdin]

* Ralph Giles (giles at snow.ashlu.bc.ca) wrote at 22:56 on 14/10/00:
> On Sat, 14 Oct 2000, Ali Abdin wrote:
> 
> > Okay - this is a problem. You see, stating that "foo.ogg" is an
> > application/x-ogg is incorrect because it is not an application.
> 
> As patrick mentioned, this is an old flamewar. At least you're complaining
> about mime stuff rather than file extensions. :)
> 
> We use 'application' because it seems to be the only catch-all for general
> multimedia content in a complex format. Same way PDF is application/x-pdf.
> 
> > What Nautilus does is check the mime super-type and if it is 'audio' then it
> > will do some special music handling functions (i.e. Sound Preview, 'View as
> > Music', etc.) This is no problem with mp3 as it is audio/x-mp3 or audio/mpeg
> > or whatever.
> > 
> > Now in Nautilus we want to support audio files (i.e. it doesn't make sense to
> > try and play a video codec using 'ogg123'). Is this possible at all?
> > 
> > For the mime magic detection stuff we check for the "OggS" at the beginning,
> > and for the extension we check for '.ogg'
> 
> You could easily extend the magic check to look for a vorbis substream. In
> the 1.0 mapping the file should always have 'vorbis' starting at byte
> 28+(the value of byte 26). In fact, I suspect byte 26 will always be 1.
> 
> This assumes the first logical bitstream header is the vorbis one, which
> is of course true of audio-only files. I suspect it will also be true in
> general, to coddle broken player implementations that don't expect other
> streams.
> 
> Of course, none of this helps keying your database off 'audio' (which
> seems wrong anyway) or using a different ogg player for audio vs. a/v
> files. I wouldn't worry about it beyond associating ogg123 with
> application/x-ogg with .ogg/OggS. If ogg123 (or whatever) turns out not to
> be up to playing both types, it can be replaced by a smart launcher that
> does content examination.
> 
> The problem with having both audio/ogg and video/ogg (and text/ogg) is
> that webservers would have to do the complicated content examination 
> I described above to set it properly. Arguably they should be allowed the
> easier time...and it's much easier to get Ogg support added to a media
> player than a web server.

To further elaborate on my point - I believe there needs to be two possible
mime-types:

audio/ogg (or audio/vorbis)
video/ogg (which could possible have a vorbis stream embedded inside it
because visual is usually accompanied by audio (so apps will have to handle
this))

Are there any other ogg projects besides audio/visual codecs? 

of course, since there will be two different mime-types there needs to be some
way to identify between the two using mime-magic (yes, it can be done
algorithmically, but that defeats the simplicity (not to mention speed) of the
mime-magic way). Also having to do it algorithmically means we either A) need
to use libvorbis, or B) get down and dirty with the vorbis codec

Regards,
Ali

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