[vorbis] tags in comment field - why?

[Beni Cherniavksy]

On 2001-12-26, Glenn Maynard wrote:

> Well, my last question about this was in the middle of other stuff, but
> it's a basic one: why put tag info in the comment field at all?  Why not
> use the XML field that's already there?  It gives the flexibility needed
> to do things like translated tags easily, and keeps tag info in the same
> format as other data--potentially simplifying editors which read other
> types of metadata.
>
> The only reason I've come up with is to simplify reading tags for
> embedded devices who don't want an XML parser.  A better solution for
> this, I think, would be to define the tags as XML and then export the
> data to the comment field, reducing it as necessary (ie. where there are
> multiple languages, use one based on user preferences), and always
> considering the XML version authoritative.
>
> Another thing to bear in mind is that UTF-8 data alone isn't always enough
> to render it correctly.  You need to know what language it's in, too,
> when you have CJK text.  You can guess--chances are, if it's my file,
> it's Japanese, not Chinese--and less intelligent renderers will just
> select a font and if it's the wrong one, display the wrong thing.
> However, it'd be nice to allow it to be done right; to allow programs to
> let me choose MS Gothic for Japanese and NSimSun for Chinese.  (IE allows
> this.)
>
Erh...  Good point.  That's a question to Unicode, though.  Why did they
do it this way?  I thought there is single glyph per unicode character but
you know better...  What format can currently do better than unicode?  How
does IE do it - it checks the language of the file?  Then what about a
Japanese/Chinese mix?  Or does it check the LANG properties in HTML tags
delimiting parts of the text?

> Why put tags in a separate, severely limited format?  ID3V1 did that
> (at orders of magnitude worse, of course), and the switch to ID3V2 was
> painful.
>
ID3v2 didn't fix it.  It's still more limited than vorbis tags.  I won't
speak for Monty on the original decision but using XML is overkill.


-- 
Beni Cherniavsky <cben at tx.technion.ac.il>
                 (also scben at t2 in Technion)
I like Common Lisp* more than Common Source
   and Open Source  more than Open Collector.
(*)Scheme is better than any scheme.

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