[ogg-dev] embeding xml to ogg

[Martin Leese]

Oleksij Rempel <bug-track at fisher-privat.net> wrote:
> Ok,
> you are right, using existing technology will save time :)

What has not yet been discussed is what you
are streaming *to*.  That is to say, what
software is going to receive the metadata, and
what will it do with it.

This is important because VorbisComments
can contain pretty much anything you want.
Suggestions for field names (keys) and field
values are just those, suggestions.  Whether
suggestions make sense for your particular
application depend on what your metadata will
be used for.

> please correct me if i'm wrong:
> 1) datetime
> in different sources i got different description. At the beginning i
> thought the DATE tag can be used only with DATE=YYYY-MM-DD
> According to this:
> http://wiki.xiph.org/VorbisComment#Date_and_time
> i can use: YYYY-MM-DDTHH:MM:SS+TS
> is it correct?

Correct, the suggestion is to use the ISO
scheme.  I don't recall which specific ISO
standard this is; perhaps somebody else can
remember its number.

> 2) keywords.
> it is not the same as DESCRIPTION. What tag should i use for keywords?
> In case of dc we usually use dc:subject.

VorbisComment field names (keys) are case
insensitive.  However, the convention is to use
uppercase, so I would stick with DC:SUBJECT,
DC:DESCRIPTION, JOBREF, etc.  Note that
keys cannot contain the tilde character, ~.

> 3) DECRIPTIO - clear, no problem.
>
> 4) LOCATION, i would use computer guid and host name. Is it ok?
> or is it "Tantalos resource ID"

Use whatever works best for your application.
(I have never understood what a "Tantalos
resource ID" actually is.  It does not seem to
be widely used.)  Note that field values must
contain only UTF-8.

> 5) we also need do some kind of booksmarks at record time.
> it should know only the time where button "bookmark" was pressed.
> is "Chapter Extension" correct way to do this? Is it possible to use
> only one time "CHAPTER001=00:10:00.000"? Usually second time is unknown
> any way.

The Chapter Extension is intended for indexing,
and is expected to have a second time.
Instead, why not use BOOKMARK=... ?

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