On Sat, 17 Apr 2010 16:50:06 +0200 Alexandre Ratchov <[email protected]> wrote:
> On Sat, Apr 17, 2010 at 05:27:30PM +0300, Sviatoslav Chagaev wrote: > > DELL Latitude D400 laptop reporting in! > > > > At first, I accidentally compiled the kernel without the GEM option, as > > a result, when I ran X, the screen just went black, and even when I > > killed the server through ssh, the screen never recovered. > > > > Everything seems to be working ok. > > > > I played with Mplayer a bit and noticed that the good old 'stroboscopy' > > video was still there. I.e. when there is a lot of motion, the video > > kinda like slows down periodically (each second or so) and then goes to > > normal, possibly dropping some frames or effectively dropping them by > > playing the frames which are being late very fast so that the brain > > doesn't have a chance to perceive them. Then it occured to me to try > > Mplayer's -nosound option, and the video then played real smoothly. > > Then I `pkill aucat` and tried playing the video again, it was just as > > smooth as with '-nosound'. Here's a video which demonstrates the > > effect: (I suggest watching it with aucat not running, since if it does > > the same effect for you, you won't be able to see the difference) > > > > http://yy.lv/download.php?f=122601 > > > > first, the video is played with mplayer's -nosound option > > then, `aucat -l` is started and the video is played > > finally, `pkill aucat` and the video is played > > > > This problem, 'stroboscopic' video when there's a lot of motion, has > > been bugging me for a long time now, as long as I can remember in fact. > > So I can't really tell whether earlier it was due to bad performance of > > the video drivers or because of aucat, since it never occured to me > > before to try -nosound. > > > > This effect is caused by the clock resolution not being high > enough. > > Mplayer is using the sound card clock ticks (determined by > the audio block size) to sync video to audio, and the > default block size of aucat is too large. > > Could you confirm that video is smooth if you > use ``aucat -l -z 480'' ? Yes, it worked, with -z 480 the video plays just as smoothly as with -nosound, thank you and sorry for the false alarm!
