[ogg-dev] Fixing ogg vorbis corruption caused by bad metadata

[Adam Rosi-Kessel]

Adam Rosi-Kessel wrote, on 6/19/2009 3:56 PM:
> Conrad Parker wrote, on 6/18/2009 3:15 PM:
>> Hopefully at some point the vorbis data in the file becomes valid.
>> Perhaps we just need to know the original encoding settings to create
>> a new file with valid codebooks and splice them together: oggz-dump -r
>> should be ok for that, just take the first 3 packets of the new file,
>> and packets 17 onwards (or 100 onwards) of the original file ...
>
> I've been able to replicate the corruption reliably now. It appears to
> be caused by the metadata tagger trying to embed too-large album art. I
> have a "before and after" ogg that should only be different by the
> metadata album art tagging. I tried swapping in the "before" header into
> the "after" file, but still couldn't play the fixed "after" file.
>
> I've put hex dumps here:
>
> http://adam.rosi-kessel.org/bugs/liboggz/484/original.hexdump.bz2
> http://adam.rosi-kessel.org/bugs/liboggz/484/corrupted.hexdump.bz2
>
> Does this shed any light on exactly what the corruption is and/or how to
> fix it?

How about another approach -- is there a tool that will verify the page 
checksums? oggz-validate doesn't seem to do this. If the page checksums 
are okay, then doesn't that suggest the streams are also recoverable?

Adam