[Vorbis] .ogg extension and Theora

[Arc Riley]

<000701c49cf0$95067910$a720a8c0 at NESCAFE>
Message-ID: <20040617202339.GB17559 at xiph.org>

On Fri, Sep 17, 2004 at 09:57:37PM +0200, Nescafe wrote:
> > And who draws the line between "audio" and "audio+subtitles"?
>
> The file extension.

<SARCASM>

Great idea!  Ok, here's a proposal:

.oggvorbis		# Just Vorbis
.oggwrit		# Just Subtitles
.oggvorbiswrit 		# Vorbis w/ Subtitles
.oggflac 		# Just FLAC
.oggflacwrit		# FLAC w/ Subtitles
.oggspeex		# Just Speex
.oggspeexwrit		# Speex w/ Subtitles
.oggtheora		# Just Theora (no audio)
.oggtheorawrit		# Theora w/ Subtitles (no audio)
.oggtheoravorbis	# Theora w/ Vorbis
.oggtheoravorbiswrit	# Theora w/ Vorbis and Subtitles
.oggtheoraflac		# Theora w/ FLAC
...

You get the idea.  This goes on for several hundred more as we add MNG
subtitles, which are overlays not textual subtitles, and double the size
of this list everytime you add an additional codec.  I should add:

.oggvorbisflac		# Vorbis and FLAC chained together
.oggvorbisspeex		# Vorbis and Speex chained together
etc...

Since it's completely legal to have an Ogg file with multiple bitstreams
chained end-to-end of different codecs.

Ah, I can hear you now.  "Several thousand different extensions is just
too much to handle!  We just need to lump these into TYPES, not CODECS"

Ok.

.oggaudio
.oggtext
.oggoverlay
.oggvideo
.oggaudiotext
.oggaudiooverlay
.oggaudiovideo
.oggtext
.oggtextoverlay
.oggtextvideo
.oggoverlayvideo

This list doubles everytime a new TYPE of codec is created...

uh-o!  What about MIDI?  What catagory is MIDI in?  It's kinda audio,
but it's scripted audio!  Is it a script type?  Or is it something
specific on it's own?  After all it doesn't output PCM, it outputs
notes, like the difference between textual and graphical subtitles.

What about if you want different icons for when it's midi or vorbis?  Or
Vorbis and Speex?

Better go back to the thousands of different extensions, as above...

</SARCASM>

No.  Absolutly not.  The file TYPE is Ogg.  It's .ogg for a reason.

Use something else to tell your files apart.  Not extension.

> The problem is not really about which player will manage to open your file.
> It's about quickly identifying which one is audio, which one is video,
> according on the oldest and simplest file-system metadata I heard about :
> File extension.

You're right, it is the "simplest".  It's also wholly ususable for this
purpose, as it is unusable for most purposes.  Use something else.

> It enables the use of simple file managers like Windows', and doesn't break
> the more advanced ones. I see nothing against that.

Yes, it actually does break "the more advanced ones".  When you upload
such files to webservers the admins need to add the extension to the
mime-types file so it can properly tell the receiver what mime-type it is.

> The birth of the OGM extension speaks for itself. There was a need, it was
> filled. I just hope Xiph will officially support this *kind* of simple
> tricks, if not *that* one.

.ogm is not Ogg.  It's something that somebody else wrote as a cross
between AVI and Ogg.  It's also been abandoned, as a project.

If you want to solve this problem on Windows, write something that
plugs into the preview thing on the file manager (if you even have one)
that gives you the codecs which are used, prehaps also with play length
etc.  Or whatever else you want.

We are not going to impose a bunch of stupid rules and exceptions that
serve to make Windows users lives a little easier at the expense of
the time and confusion of every non-Windows user.