Bernhard Praschinger wrote: > > In the RC2 there was at high chosen quality factors (-q 1-4) a problem > that the quality fell, to a -q factor down to at 10-15. > That does not happen in the RC3. The Quality factor is lowered, but in a > way that makes sense. Dropps from -q 3 to 3.4 - 5.6.
I am under the impression that RC3 has poorer control over the max bitrate as reported later by mplex. It's like it either can't get close enough to the specified maximum (for -b 8000 -q 8 it only gets to 7400 for one file, and lower, sometimes much lower, for all other files) or it gets too high and overshoots if I start pushing -q just a little bit (for -b 8000 -q 7 it's already 9200 on one file, 8800..8900 on several other files). It's hard to tell precisely without doing more tests, but it seemed like RC2 and older did not overshoot the max so suddenly with only minor changes for -q. See my previous messages in this thread. Again, the source material is a new but cheap DV camcorder, rather noisy in low light, I'm shooting from hand - no tripod, no filtering/processing is done on the video stream. I am transcoding to the -f 8 format for DVD. I am trying to maximize the image quality while keeping the VOB file parameters "legal" (there's only one sound track, AC3 192k, multiplexed with mplex, then authored with dvdauthor in a single-title multiple-chapters disk with no menus). A sample of mpeg2enc options is: mpeg2enc -v 0 -I 1 -f 8 -b 8000 -F 4 -n n -a 3 -o file.m2v -c -q 5 -4 1 -2 1 -s -D 10 -K kvcd -R 2 -M 2 I only modify -q in these tests. -- Florin Andrei http://florin.myip.org/ ------------------------------------------------------------------------- SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
