Has anyone noticed mpeg2enc rc92 creating odd "flashing" artifacts on what should be otherwise generally smooth color backgrounds? I've attached a small jpeg (29k) showing an example of the artifact. If you look to the right of the tall actor's shoulder, you can see very clearly what I'm talking about, it's a nice herringbone pattern of mpeg encoding subblocks (I'm not sure of the official name). When playing this video file, the herringbone pattern fades in slowly, then disappears. And this frame is not the only instance, it's just the one I paused on to capture to jpeg.
The mpeg2enc encoding parameters I used (yes, I know some of these are defaults, but...) is my standard entry I've been using for Carnivale (the frame is from about 14 seconds into this past Sunday's Carnivale on HBO), which is: -f 5 -n n -a 2 -V 230 -B 224 -S 8000 -b 9576 -q 10 -I 1 -G 54 -H -N 0.0 -X 200 -Q 4.0 -R 0 -d -4 4 -2 4 The only difference between this set of parameters and the set I have been using with rc91 is the addition of "-R 0" to obtain only P frames. An encoding run of Carnivale with rc91 produces an encoded file that's just as I've been accustomed to obtaining. There are no artifacts visible to me on screen when I play the same section of the rc91 encoding. I'll leave a run of rc92 without -R 0 running overnight to see what it does when encoding both P & B frames and report the results in the morning.
<<attachment: artifact.jpg>>
