I'm running Snow Leopard and have a serious issue with QuickTime X. I have a Samsung HMX-H100N/XAA camcorder that records H.264 video in either 720p or 1080i. In either of these resolutions, QuickTime X (and, by extension, all QuickTime-associated applications like FCP, iMovie, etc.) displays an incorrect aspect ratio for all video produced by this camcorder. For example, 720p video is reported as being 1280x720 in the movie inspector (which is normal), but the displayed size is always at an aspect ratio of something like 63:20 (never heard of such a ratio) with sizes like 1700x539.

If I open the video in QuickTime 7 player on the same computer, it is displayed correctly. If I process the video through something like MPEG Streamclip to transcode it, it displays correctly. As it stands right now I have to transcode all of my video in order to use it in any iLive (or other QT-based application) unless I want it to look ridiculous. I've tried installing Perian, but that seemed to have no effect.