If you haven't updated to Quicktime 7, then I really suggest you do so now, so as to benefit from its latest features, one of which is the H.264 codec. If you can't, or if you want to keep your old version and still want to enjoy H.264 quality, then your best bet is to install the x264 Quicktime Codec.
H.264 is fast becoming a standard for video compression becomes it offers excellent quality in a smaller whether on an HD quality movie, a 3G playback or a regular internet stream.
Installing the x264 Quicktime codec is easy, it only takes a few seconds, and once set up you needn't worry about it. The codec comes into action as soon as you launch Quicktime. You'll then be able to benefit from the best image quality and enjoy your movies and videos.
The x264 Quicktime codec will bring support H.264 support to versions of Quicktime 6 or under. Your best bet is still to update to version 7 though.
- Sync core to x264 git-1698 and ffmpeg SVN-24798.