I recently encoded a screencast using x264. The video is here:
It works fine in VLC, but QuickTime claims it needs extra components to play it. I'm confused. I thought x264 was a clone of H.264, which QT has native support for?
Anyway, a friend of mine is having trouble getting it to play back on Mac OS X (10.6.8), and I see the same problem in my Windows 7 box. Either I did it wrong or I'm missing something.