Kbm_telemark_carving_apex1.ogv and Mount_Saint_Helens-ffmpeg-600-1920x1080.ogg hit a bug in oggThumb where the page size is slightly larger than the page size in the test files Greg sent me to test large page size handling. I've committed a fix and it can be deployed soon.

Rockerbll_web_Test.ogg is a 25 second Theora stream multiplexed with a 36m56s Vorbis stream, so it's not surprising that it has trouble getting a Theora snapshot at the 18 minute mark.

I also found Bb_bamboo_isle.mpg.vbr1400.80.8to91.theme.ogv which has been cut down in duration with a buggy tool, possibly oggz chop, which has left it with a damaged skeleton stream and no EOS marker on any of its three streams.

Instead of reopening this bug every time you see a thumbnailing failure, I would suggest at least running "oggz validate" on the file to test for common encoding errors. To test for mismatched lengths in multiplexed files, you can use oggSplit from oggvideotools, followed by oggz info.

We could have MediaWiki display such validation information based on the PEAR File_Ogg scan, but that should be filed as a separate feature request.

The fix for the page size bug is deployed, and since that was the only server-side issue, I'm marking this resolved.