I’ve had a few of those in the past too. I’m not sure what 'undf' audio stands for.*
I’ve found (on Windows) that both VLC and Media Player Classic - Home Cinema can’t play such files.
However Wimpy’s flv player (freeware) can handle such files fine.
There’s a version for the Mac, so I suggest you give it a try (though I can’t vouch for the results since I don’t own a Mac).
Feel free to report your results.
* here are just personal anecdotes: mediainfo in one sample says ADPCM audio, but on some forums i’ve seen voxware metasound mentioned; the former should be supported in VLC, but perhaps it’s packaged differently in flv? (if I recall, mu-law audio is packaged differently in mov files, which is why WMP can’t play it in mov files, but can in avi files)
Okay, Im sure that something similar has been discussed several times already, but I couldn’t find the exact thread, so I’m making a new one.
For years, I used to keepvid to download YouTube (and other videos) as .flv files to my Mac (which runs OS X 10.3.9, btw), where I would use VLC to play them. But a couple of months ago (after YouTube’s latest revamp) keepvid stopped supporting my downloads, and when I downloaded vids by using Safari, I got that “fourcc 'undf' " error that prevented anything from playing. Very annoying. How do I get around this?
(OT: for some reason, Safari crashes when I go to YouTube these days. Weird, it’s one of their supported browsers.)
Help! Thanks in advance.