[ogg-dev] Re: [theora-dev] Re: [Advocacy] Re: [Vorbis-dev] Proposal: An extension to rules all others

Silvia Pfeiffer silviapfeiffer1 at gmail.com
Sat May 5 23:52:24 PDT 2007

Hi Ian,

There are lots of good comments in your email and I have made
adjustments to the wiki page with some of the points.

More comments inline...

On 5/6/07, Ian Malone <ibmalone at gmail.com> wrote:
> if it was practical I think it would be useful to have
> apps supporting .oga, .ogv MUST support decoding from muxed Ogg
> streams,

I guess for .oga this makes sense, since it incorporates audio files
and most Ogg audio is currently under the .ogg extension.
For .ogv support of generic .ogg may be useful since a generic .ogg
may be a video with additional logical bitstreams.
I've added this to the wiki, but as a SHOULD.

I guess my suggestion is that we recommend that in future everything
that is clearly ogg video should have .ogv and everything that is
clearly ogg audio should be .oga.
This also implies that .ogg is deprecated for Ogg Vorbis, Ogg Flac,
and Ogg Theora.  Apps should however continue to expect in particular
Ogg Vorbis inside .ogg.
So, what will ultimately remain with .ogg is those formats that are
not clearly audio and not clearly a/v.

> and MAY drop unrecognised logical streams?)

Yes, that's absolutely a recommendation and I've added it to the spec.

> Given that modern file managers have a stab at providing previews
> this is actually becoming more reasonable.  There is something to
> be said for simplicity, though the argument for parsing has always
> included the fact that the extension won't tell you what codecs
> the file uses (the avi problem).

I believe the file extension should solve the problem of which
application should open the file. It should not solve the problem of
identifying to codec inside the file, which is something that the
application can do and for which skeleton is much more useful.

> The important questions are:
> 1. Move on from .>3?
> 2. What should .ogg be?  So far suggested:
>   a. Legacy only.
>   b. Retained for Vorbis I.
>   c. Used for all A only.
>   d. Retained for corner cases.
>   e. Retained Vorbis I and miscellaneous.

You are missing:
f. anything in a Ogg container can use the .ogg extension, but it is
recommended to use the more specific .oga and .ogv extensions for
those that are clearly A only or clearly A/V.

> 3. What about corner cases?

What do you regard as a corner case?

> Finally (as I try to avoid work), I've observed my iAudio
> player recognises Vorbis by the .ogg file extension.  Files
> ending .oga or .ogb wont play, they don't even show up.
> Cowon has been pretty good about working on their Vorbis
> support, but I suspect manufacturers of the cheap players
> that have started to show up playing Vorbis won't care so
> much.  What would be a bad idea is throwing away progress
> made so far.

Yes, I agree. Thus the suggestion to continue to support .ogg for Ogg
Vorbis, but deprecating its use for the future.

But maybe this is not taking it far enough. Maybe we should use .ogg
exclusively for Ogg Vorbis I (because of the HW players) - and then
use .ogx for "anything random inside ogg"? And future Ogg Vorbis files
with skeleton should then be recommended to use .oga? Hmm...

> What does Xiph have control over?  The larger the existing
> player base and number of existing files in the wild the
> harder it is to change.

Agree here, too. And that's what got me thinking that maybe we should
keep .ogg around for Ogg Vorbis I exclusively, since the largest
number of .ogg files in the wild will be exactly that. There are much
less that are Ogg Flac or Ogg Theora and they are not supported by HW

Can we post-hum call Ogg Flac or Ogg Theora files that use the .ogg
extension "misnamed" without pissing off our community?


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