[Vorbis-dev] OggDisk?

[Ian Malone]

(Hi to all at XSPF, for the original post see
<http://lists.xiph.org/pipermail/vorbis-dev/2007-May/018847.html>)
Petr Tomasek wrote:
> On Sun, May 06, 2007 at 05:10:27PM +1000, Silvia Pfeiffer wrote:
>>>>  - having "more levels" - so you can have e.g.
>>>> "a film" -> "a collection of films" -> "a collection of collections"
>> Here's my take on how to do this, and it mostly agrees with Ian:
> 
> Sorry, but I didn't receive any response from Ian (maybe due to some
> ant-spam filter?)

I usually reply only to the list, so maybe you're not
receiving from vorbis-dev or it's held up somewhere.

> 
>> 1) a film with chapter markers: one Annodex file, or alternatively a
>> Ogg stream and a CMML file
>> 2) a collection of films: XSPF (a playlist) & n Annodex files
>> 3) a collection of collections: multiple directories
> 
> I'm not sure You understood what I meant.
> 
> My main concern is that I think that the various Ogg* technologies
> need an equivalent of the DVD/BD-_disk_ structure, so that
> if you insert o "OggDisk" enabled media into the PC, it 
> could be automaticaly detected, "OggDisk" enabled player would
> be started and possibly (according to user's settings) an appropirate
> film / audio / ... would be started.
> 

Okay, personally I hadn't quite understood this is what you
want to do.  The next paragraph is a much clearer statement
of the idea.

<s>

> 
> So my concern is mainly about DEFINING A DIRECTORY STRUCTURE and
> calling it something like "OggDisk", that would be more or less
> equivalent to the CD/DVD/HD/BD disk definitions.
>  

This sounds worthwhile.

> XSPF would definitely be a good candidate the "root element"
> of such a directory structure, but it's intended for slightly another
> purpose (see the specs, 3.1: "An XSPF playlist describes a __sequence__
> of objects to be rendered" [emphasis added]) and has some
> shortcommings, most notably:
> 
>  * it doesn't allow for "nested" or "tree-like" playlists (which would be
> needed e.g. for collections of films sorted according to the genre into several
> sub-collections etc.)
> [See 4.1.1.2.14: "xspf:playlist elements MUST contain one and only one
> trackList element"!]
> 
>  * it doesn't describe "graphically" how the playlist is to be displayed
> (in contrast with DVD's). DVD's are on the other too much presentation-
> oriented and don't expose the "metadata" to the user. So probably
> some model that separates the semantics and presentation (in the
> same manner like CSS for HTML does) would be ideal for such a playlist.
> 
>  * it doesn't have some important elements (like thumbnail image/video
> for a/v content and for images)
> 

I don't know much about XSPF, so I'm sending you to the
people who do (mailing lists at
<http://lists.musicbrainz.org/mailman/listinfo/playlist>).
A couple of initial reactions though:
Can an XSPF specify another XSPF as an object to be played?

XML documents can include multiple namespaces, what are the
possibilities for using XHTML+CSS together with XSPF to
produce both the playlist and specify its presentation
(this is basically extending your suggestion a little).

Pure XSPF or one of the possible restatements of it,
for example microformats.  Don't know if that would
make implementation or presentation simpler.

One of the ideas I had a while ago about Ogg metadata
was to put RDF or XSPF playlists in Ogg streams to
describe their relation to larger collections (at the
time I was thinking of tracks in an album).

Anyway, the XSPF guys know much more about XML than
I ever did.

The more I think about OggDisk the more it seems like
something we need.

-- 
imalone