When I try to play a DVD with mplayer (mplayer -vo x11 -zoom -dvd 1) it lags. Every second or two it pauses for about 0.5 seconds. If I instead of playing directly from the DVD copy it to my harddrive (cat /dev/cdrom > ~/swordfish) then play that (mplayer -vo x11 -zoom -dvd 1 -dvd-device ~/swordfish) it is not choppy. However doing this takes to long. I'm running Red Hat 8.0, KDE, and NOT the mplayer it came with. When I play the DVD with windoze on the same computers there is no problem. I observe the same effect on both my desktop and laptop.

Desktop: 1.3GHz (underclocked, don't ask why) AMD Athalon XP 1800+, 256 MB DDRAM, 32MB GeForce 2.
Laptop: 1.3GHz Celeron, 256 MB RAM minus 32 for the video card SiS 630/730.

Also on my desktop I keep getting "your system is too SLOW" errors while playing DVDs or MPEGs

Thanks.

why are you deliberately using the slowest, most ineffecient X output available?? use xv.

Thanks for the tip. I will use xv. However the DVD still lags.

enable dma for your dvd player. you need to be logged in as root (maybe distro dependant. i know rh 7.3 will not let me run hdparm su'ed into root) and run the hdparm command on your dvd player. basically:

hdparm -d1 /dev/hdx

where x is the right device label for your dvd player.

also just to note if that command says permission denied (even as root) or if this change doesn't persist after reboot, then just add that line to your rc.local or rc.sysinit file..

yes. that's good advice there. i shoulda remembered that cause the setting wasn't persistant for me on reboot. i had to add that command to /etc/rc.d/rc.local .

Sorry for delay. Thanks for advice, but it's still choppy. Not sure, might be less choppy though.

does your dvd player handle dma? i'm just asking cause my old man is having problems with his laptop with enabling dma failing. log in as root (or if you're distro lets you use hdparm su'ed as root just open up a shell in your user account), open up a shell and type this command:

hdparm -v /dev/hdx

where x is the right letter for your dvd drive.

look on the about the third line that says something like "dma_enabled". to the right of that should be the number "1" if dma was successfully enabled. if it's not enabled try the command a couple of posts up and look carefully at the output. look at the last line of output. if it says something like dma failed, then you too, like my dad, is having problems enabling dma for your dvd, which would explain the choppy playback. if that's the case, i can't help you as i'm still trying to get help on that myself.

of course, it could be that you do not have the enough ram or a fast cpu either. but i don't know about that since you didn't post your specs.

I have just recently had started to get the same problem, I cant seem to get hdparm to work it gives me an answer like

"linux:~ # hdparm -t /dev/hda /dev/hda: Timing buffered disk reads: -1754 MB in 0.00 seconds = -inf kB/sec Hmm.. suspicious results: probably not enough free memory for a proper test."

So I havent the slightest. This is my system AMD AthlonXP +2400@400mhz
512mb DDR, Nforce2+Nvidia GeForce4 Ti4200 with all drivers
currently mem used is 146/512MB with 10MB swap used.

glx gears
24750 frames in 5.000 seconds = 4950.000 FPS
24330 frames in 5.000 seconds = 4866.000 FPS
25358 frames in 5.000 seconds = 5071.600 FPS
25471 frames in 5.000 seconds = 5094.200 FPS

Im thinking that maybe there are to thinks running in the backround. Im using SuSE 8.2 I think that might be part of the prob with the hdparm thing though.