ogg corruption

[Jeff Mitchell]

Bart wrote:
> On Mon, Mar 3, 2008 at 9:19 PM, Jeff Mitchell <kde-dev at emailgoeshere.com> wrote:
>   
>> Bart wrote:
>>  > Hi all.
>>  >
>>  > Where do I go to discuss Amarok bugs? I just found that tagging my
>>  > oggs with it corrupts the metadata, and makes these file unplayable...
>>  > I'd like to know where to discuss the details, since I don't even know
>>  > what is doing the actual tagging yet.
>>  >
>>
>>  Tagging is done via the tagging library Taglib.  You didn't include any
>>  information about what version of Amarok, what distribution, etc.  Many
>>  distributions are still carrying the original vanilla Taglib 1.4
>>  release, which has known issues -- many other distributions have
>>  packaged SVN snapshots of Taglib or the recently-released version 1.5.
>>
>>  I would encourage you to write back with much more detailed
>>  information.  Versions of everything, exactly what you did, what the
>>  corruption entails, and so on.  We may end up forwarding you to the
>>  taglib list or may have some other suggestions for you.
>>     
>
> Gentoo, with amarok 1.4.8 and, indeed, taglib 1.4-r1.
>
> I produced a simple set of before and after (ogginfo gives details,
> ogginfo throws a fit, respectively), where the one action I did in
> amarok is changing the album name (though I assume any type
> of tag edit would do it)
> I  think also have oggs for which this did not happen. Anyway.
>
>
> Via binary diff I know that the only changes in the file were made to
> the second Ogg page, the one that stores the vorbis stream
> metadata and comments.
>
> I just wrote a simple Ogg header decoder that suggests that taglib
> changed the data in this page but didn't properly rewrite the header.
> I figure this because:
>
> - The header's segment table would indicate that the page ends
>   before it actually does. The table is the same as it was in the before
>   file, and the page size you would calculated from that table *is*
>   exactly right for that file.
>
> - The checksum is bad for only that single new page - though it not
>   the same checksum as in the before file, so the header wasn't
>   just copied verbatim.
>
>
> --Bart
>   
Bart,

I know the Gentoo maintainer is planning on putting taglib 1.5 into 
portage along with a recent Amarok SVN snapshot as well.  Fairly soon if 
I'm not mistaken.  I'd appreciate you trying things out at that time.

Thanks,
Jeff