Ah, you are probably right about the playback. I have both installed - if you say it's XiphQT that enables Safari to use Theora, you're probably right. As for

Ah, you are probably right about the playback. I have both installed - if you say it's XiphQT that enables Safari to use Theora, you're probably right. As for the encoding, I was using ffmpeg2theora 0.25, which according to the release notes bundles libtheora 1.1. Whether or not I'm using it optimally, though, I can't say. I was loosely following the instructions for batch encoding here: http://diveintohtml5.org/video.html http://diveintohtml5.org/video.html .. but no matter what I do, the .ogv comes out looking like a poorly encoded DivX. Anyway I'll keep trying, thanks for the correction on the QT plugin.