[ogg-dev] Re: [Vorbis] metadata

Ian Malone ibm21 at cam.ac.uk
Mon Nov 21 02:02:05 PST 2005


Conrad Parker wrote:
> On Sun, Nov 20, 2005 at 12:44:50PM +0000, Ian Malone wrote:
> 
>>Skeleton
>>also has the problem for simple applications that it wants to be
>>the first page, which will cause libvorbisfile based Ogg/Vorbis
>>players to choke.  Not that libvorbisfile doesn't need to be
>>updated to play something that isn't strictly Vorbis-I anyway;
>>but, as it is, players which do return-value checks seem to survive,
>>as long as they get the Vorbis bos first.
> 
> 
> yeah, this is a more general problem with libvorbisfile -- it's not just
> that libvorbisfile expects vorbis to be the first bos page, but that it
> also expects the stream to contain only vorbis logical bitstreams. It
> fails similarly on streams containing theora video.
> 

Yes, I think the thing to do is keep a list of serial numbers in each
link.  Pages other than the Vorbis serial number for a link are then
dropped (including for purposes of seeking).
<http://lists.xiph.org/pipermail/vorbis/2005-October/026054.html>

I don't know what the official position is, but it seems best to keep
libvorbis as a simple Ogg/Vorbis playing library rather than make it
into something else.  That said, you wouldn't need to go much further
to identify which of the streams in a file was Vorbis content.
(Also: the addition of metadata should probably break as few things
as possible.)

-- 
imalone


More information about the ogg-dev mailing list