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

Daniel Aleksandersen aleksandersen+xiphlists at runbox.com
Sun Sep 9 05:24:04 PDT 2007

On 2007-09-09, Silvia wrote:
> Daniel,

Hi Silvia,

I realise I should have started with this. I got a little carried on with my 
ideas. Apparently I am no good when it comes to sharing an idea.

Short answer: The format should describe media content and relation between 
them in an Ogg stream. Intended usage is media management and sorting 
trough search and media manager software.

Long answer: See below.

> before you step over everything that has been done before, we need to
> determine what exactly is the use case for your new specification.
> What concerns metadata, we currently have:
> * vorbiscomment - this is a header at the beginning of a logical
> bitstream which has metadata that refers to the complete file; there
> is a specification, which has been public for a long time and is the
> de-facto standard that is (or should be) used by all software (see
> http://xiph.org/vorbis/doc/v-comment.html)
> * cmml - this is a logical bitstream for time-continuous textual
> annotations (metadata) for ogg files (see
> http://wiki.xiph.org/index.php/CMML)
> * skeleton - this is an extension to the ogg bitstream format, which
> has all the encapsulation-specific low-level metadata (see
> http://wiki.xiph.org/index.php/Ogg_Skeleton)
> All of these are supported by xiph and may need further
> work/extensions or potentially a replacement if they are not fit to
> provide what is required.
> Before throwing out more random specifications, could we please look
> at what you are trying to achieve with the new format? Can you tell us
> where the existing technologies are lacking?

What I want is a format to give a detailed description of the content in an 
Ogg stream. The usage would be improved searchability on local machines 
(possibly even on the web and file sharing clients too) and sorting in 
media management software such as Apple iPhoto, Amarok, and WinAmp.

Currently only Vorbis comment describe the content. What I aim to is to 
replace Vorbis comments. Vorbis comments are very limited to a few field 
names for describing content. There is only a poorly developed look-a-like 
standard for describing audio files; and all other media formats are left 
alone. End users may indeed slap on additional field names, but no media 
management software no search engine know to look for them.

Another thing this format describes is relations between media in an Ogg 
stream. See the audio:collection:artwork element for instance. (Imagine an 
audio:lyrics element too.)

This random specification was intended to start development for a real 
metadata/content description format. This XML based thing I have put 
together in a few hours might not be the best. But it does provide a better 
way to detail describe

I have no doubt that others can do this better. But as no one seamed to be 
working on a description format; I took it upon myself to start working on 

Hope this clarifies things.
Daniel Aleksandersen

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