[ogg-dev] Additional ogg audio fomats (speex, flac, PCM)

[Ralph Giles]

On Sat Jun  2 07:19:14 2012, clancy hood wrote:

> a) a command-line utility that allows me to encode to non-vorbis ogg
> audio (*nix)

There's not really a single utility. You can make .spx files
(speex-in-ogg) with speexenc, ogg flac files with 'flac --ogg', and
.opus files (opus-in-ogg) with opusenc.

> b) example files of the above

You can get an example opus file (with metadata) at
http://people.xiph.org/~giles/2012/opus/ehren-paper_lights-64.opus

You can find some speex file e.g. at
http://people.xiph.org/~giles/2008/lca/mirror/Wed/

Ogg Flac isn't very popular; it's mostly useful for muxing with video. I
don't have any examples handy.

No one uses ogg pcm at all. I think there are some experimental
implementations, but I don't remember where they are. I wouldn't
worry about that one.

> Am building a program part of which reads stream meta from uploaded
> audio files, and so have written a lightweight getid3-like set of
> classes that do this. Am handling ogg vorbis perfectly well already
> and would like to test it against the others.

Neat. Have you looked at calculating the file length so you can set the
Content-Duration header when serving the files back?

> Additionally (out of pure interest) does anyone know of good
> literature pertaining to examples of (ab)using libogg to package
> arbitrary audio formats?

We generally discourage this, since our mission is to provide
royalty-free, libre multimedia technology. However, if you have a
specific audio format in mind, this is a good place to talk about the
best way to define an Ogg encapsulation method.

HTH and thanks for supporting Ogg,
 -r