[vorbis] Removing Vorbis tags

[Beni Cherniavksy]

On 2002-01-13, Ross Vandegrift wrote:

> > What's wrong with using vorbiscomment and sed/bash/perl?
>
> This:
>
> ross at turalyon:~$ ls -R /opt/music/ | grep mp3 | wc -l
>    1106
> ross at turalyon:~$ find /opt/music -name '*.mp3' | xargs du -ch
> 1006M   total
> ross at turalyon:~$ ls -R /opt/music/ | grep ogg | wc -l
>     476
> ross at turalyon:~$ find /opt/music -name '*.ogg' | xargs du -ch
> 867M    total
> ross at turalyon:~$ time for i in `find /opt/music | grep mp3`; do \
> 	id3ed -r $i; done
>
> real    0m39.164s
> user    0m4.590s
> sys     0m2.530s
>
> ross at turalyon:~$ time for i in `find /opt/music | grep ogg`; do \
> 	vorbiscomment -w $i < /dev/null; done
>
> real    20m58.437s
> user    1m12.280s
> sys     0m26.210s
>
>
> There's a big difference.  I've started hacking together a small program to
> manipulate vorbiscomments in a very basic (hopefully fast) way.  The issue is
> that vcedit_write () works only like a pipe, so the input and output files
> can't be the same ogg - so for every comment that vorbiscomment edits, a full
> copy of the file is written to a temp file, updated with the vcedit functions,
> and then written back to the original filename.
>
> I'm looking for a way to edit the comment headers without having to
> vcedit_write, but haven't read enough code yet.
>
How about deciding about a standard format for stand-alone files that
contain only the tags.  vorbiscomment would write to the separate file if
instructed (an option), ogginfo would always look for such a file.
When finished doing many updates of the tags, you would call vorbiscomment
with yet another option that writes from these cache files to the oggs
themeselves.  You can already do this yourself with vorbiscomment but
ogginfo ignores it.  Most software should support such a scheme to make it
useful.  Also, in such a case the format should not have any limitations
(e.g. linefeeds in comments - does vorbiscomment handle them?).  There are
laso problems with multi-chapter ogg files.

Really, a little padding in the comment field for direct write-overs would
be ideal.  Is this possible with the format?


-- 
Beni Cherniavsky <cben at tx.technion.ac.il>
                 (also scben at t2 in Technion)

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