The Longer Version: I have Perian 1.2 installed on a G5 (PPC) running OS X 10.5.8. It is connected to a calibrated LCD HD TV. I am playing mkv files encoded with X.264 and AAC audio. When I play TV shows (30-60 min programs, 720p, 500MB-1GB) using Front Row or Quicktime, they are dark, muddy, and over saturated. When I play those same videos in VLC, they look fine.Video tracks now have their colorspace set based on the size of the video.
But, the problem doesn't seem to affect movies. All of the movies (>60 min, 720p,>1GB) I have tested look fine.
If I revert to the previous version of Perian, it looks fine. When I reinstall Perian 1.2, the problem comes back.
Mac OS X 10.5.8
Power Mac G5 Dual 2 GHz/3.5 GB RAM
42-in Toshiba Regza HD LCD TV (calibrated)