[ogg-dev] embeding xml to ogg

[Martin Leese]

On 6/4/12, Benjamin M. Schwartz wrote:

> On 06/04/2012 04:08 PM, Martin Leese wrote:
...
>> The optimal solution is described at:
>> https://wiki.xiph.org/XMLEmbedding
>
> As that page says, "This page is for development of a specification for
> embedding XML streams in Ogg.".  "XML streams" are not simply XML
> documents.  They are _temporally subdivided_ XML documents, such as Jabber
> (XMPP) conversation streams.
>
> I'm not an expert on XMP, but given that it's typically applied to still
> images and PDF files, I'm pretty confident that XMP documents are not
> meaningfully XML streams, so applying temporal muxing would not make sense.

XMLEmbedding is intended for both XML files
and XML streams.  The former would be used
with things like M3F and, in this case, would be
stored near the start of the Ogg container
before any audio/video data ("chained" and
not "grouped").  There is a little more
information on the Metadata page at:
https://wiki.xiph.org/Metadata#XMLEmbedding

M3F is another draft that seems to be
moribund, having not been touched since 2008;
visit:
https://wiki.xiph.org/M3F

>> However, this draft hasn't been touched since
>> 2007.
>
> That's because, as it turns out, almost no one actually wants to mux
> temporal XML streams into Ogg.

Indeed, nobody has requested this.  However,
XMLEmbedding can accommodate it should it
ever be so.


On 6/5/12, Oleksij Rempel wrote:
|| We need fallowing tags:
|| creation datetime: seconds and time zone should be included.
|| source host: it can be name or guid. to organise created files by sources.
|| keywords,events.
|| date and person ho did transcription of record.

To me, this looks like a job for three or more
separate VorbisComments.  You might want to
choose keys which typically are not used for
other things.  For example, don't use DATE as
this typically stores the date the track was
recorded.

Regards,
Martin
-- 
Martin J Leese
E-mail: martin.leese  stanfordalumni.org
Web: http://members.tripod.com/martin_leese/