[ogg-dev] The use for an XML based metadata format

Silvia Pfeiffer silviapfeiffer1 at gmail.com
Sun Sep 9 13:44:07 PDT 2007

Hi  Daniel,,

> I really have to ask you: Have you even tried to describe media using the
> excising solutions? I don't mean adding subtitles and editing stuff. I mean
> really say what a Ogg file contins. There is no working wheels for this.
> Vorbis comments--used in FLAC too--can describe content with a very limited
> field names (and badly enforced standards).

I have and I know they are. I am not saying your work is not needed. I
am just trying to be careful how to integrate it. Don't get  me wrong:
I like what you do and it is necessary!

All I did was propose a process that can lead to an integration into
Ogg. Replacing vorbiscomment is one big request that requires a lot of
software to change. So, you will need a lot of support from the
community to go down that path. Only if everybody agrees that this is
necessary will it happen. So, pushing you to the edge and forcing you
to defend why is a constructive way for the community to learn. Don't
give up. :-)

> On 2007-09-09, Silvia wrote:
> > Daniel,
> >
> > these are all good ideas and worth progressing. However, it may be
> > better not to merge too many goals in one format (MPEG-7 did that and
> > ended up as a big mess). So, I suggest to start by structuring the
> > types of things you want - then finding out which parts belong where
> > into existing formats such as vorbis comment, Skeleton and CMML, and
> > only then start to develop a new format.
> >
> > For example: the relationships between the logical bitstreams is a
> > very semantic description - it needs to be broad enough to enable
> > different types of applications to do different things with it. E.g. a
> > video editor will need to know that there are 3 audio channels in a
> > file and how they overlap each other and also the video channel, while
> > in contrast a speech recognizer might just want to be able to know
> > about the one audio channel in there that is speech and a music player
> > would be totally ignorant of the video channel. Just solving this
> > generically would be a big feat. It would possibly need to find a
> > place in skeleton.
> >
> > A similar argument goes for the encoding quality description and digital
> > rights.
> The rights element was taken directly from the Atom 1.0 specification, but
> with an added 'date' attribute to make this stand data stand out from the
> text.

Good. So the rights element is in pretty good shape. Now we need to
figure out what the atomic element of attribution of the rights
element should be and then put it in the right location. In today's
age of mash-ups, should there be a rights element on a file section
basis? Or just on a per-track basis? Atom does it only on a per-file
basis IIRC.

> > In contrast, the improved description of the content as in: artist,
> > band name, title, organisation involved, and people involved are
> > things that improve upon vorbiscomment and should probably be included
> > there directly.
> No. I have though *a lot* about this. You can improve Vorbis comment to some
> extent. But it is way to limited. Try describing this with Voribs comments
> and you will see my point:
> <person role="vocal instrument" uri="http://person.no/"
> xml:lang="nb-NO">Person Peopleson</person>

So we're looking at replacing vorbiscomment with a xml version? How
intensively have you looked at improving/extending CMML? Subtitles for
one would definitely be better off being added to CMML than any other


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