[vorbis] Quality & Tags

[Kenneth Arnold]

On Thu, Jan 31, 2002 at 09:16:14PM -0800, David K. Gasaway wrote:
> > Since there is already a "vendor" tag which includes library version
> > info, it makes sense to have the "encoding" tag, with the options that
> > were used to encode the ogg.
> 
> I can't say why there is a vendor tag.  It would make more sense to me if that information was 
> embeded into the encoded file (in a header or something).  The encoder version seems too 
> important to place into a tag.  The tags are just a scratch-pad, and can be easily modified and/or 
> removed at users' whims.  I wouldn't use the vendor tag as an excuse to add more metadata to 
> the tags; YMMV.

See my earlier mail -- vendor /isn't/ a tag. It's in the same header
packet as the comments, but stored as a separate bit of
information. If "users' whims" is hex-editing the Ogg file, or
modifying vorbiscomment so it rewrites that part of the comment header
also, then it is definately possible to change the vendor. Note that
vorbiscomment doesn't show it, and doesn't remove it if you give it a
null set of tags.

There's nothing preventing someone from putting in the vendor as a tag
also. I don't remember if it's actually in either official or proposed
tag spec, but if it is, it's redundant information, and if it isn't in
the spec but still in some file, it can get confusing (especially
since you can change one and not the other with any reasonable comment
tool).

If you already knew that, I'm sorry for wasting your time -- but it
didn't look to me like you did.


-- 
Kenneth Arnold <ken at arnoldnet.net>
- "Know thyself."


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