Well, I finally got high-resolution video playing back on my computer. Unfortunately, it doesn't quite seem to be flowing at full framerate yet. Looks like the Linux drivers for my motherboard's AGP slot need some work. In addition, the video drivers for my Matrox G550 have a limitation of a video size of 1024x1024. I'm not sure if that's a hardware limitation, or just an arbitrary limit that the driver author put in. Even if there is a hardware limitation, I wonder if it could be worked around in some way for 1280x720 video, which contains fewer pixels than a 1024x1024 square.
However, an alternative which already exists is to use the “texture engine” instead of doing traditional video overlay. This has advantages and disadvantages. With the G550 driver, this goes up to nearly 2048x2048. Also, you get gamma correction in the video output automatically. However, video doesn't seem to be synchronized with the scan of the monitor, so you get a shearing effect where, say, the top half of the screen is one frame of video, and the bottom half is the other. I'd get that problem with video overlay, but it was much less frequent. In addition, it just seems to be more CPU intensive, and scaling the video away from the “native” resolution slows the frame rate pretty dramatically.
I think I've finally figured out a good method for watching the video stream without the player crashing every 60 seconds when some corrupted data is received. It's amazing enough that I get a usable signal after it has been bounced off the school across the street—I have to expect some data loss (line-of-sight to the tower goes almost straight through the whole building I'm in).
So, I've been watching soothing high-definition video for the past hour. And it really is soothing—way too many pictures of nature scenes for you to think that this is being broadcast in 2003. In fact, there are so many flowers in the test streams that TPT sends out that you'd think HDTV was a pet project for a botanist (one short video was called On the Azalea Trail). Then again, there's so much green, you'd think that it was done by a golfer.
Now, I just need to figure out what needs to be tweaked so the video plays back more smoothly…Posted by mike at October 12, 2003 11:29 PM | Hardware , Software , TV , XFree | TrackBack