I have tried watching a video on Slackware 12, but Mplayer says the machine is too slow. The audio/video doesn't seem to sync.
However, on Etch, the video plays fine with Totem.

Any ideas on why the difference?

FWIW, Etch is running gnome and I'm running xfce4 on Slackware.

I have never heard of MPlayer saying a machine is too slow. Try VLC media player instead.

Here is some output from trying to run mplayer from xterm:

************************************************
**** Your system is too SLOW to play this! ****
************************************************

Possible reasons, problems, workarounds:
- Most common: broken/buggy _audio_ driver
- Try -ao sdl or use the OSS emulation of ALSA.
- Experiment with different values for -autosync, 30 is a good start.
- Slow video output
- Try a different -vo driver (-vo help for a list) or try -framedrop!
- Slow CPU
- Don't try to play a big DVD/DivX on a slow CPU! Try some of the lavdopts,
e.g. -vfm ffmpeg -lavdopts lowres=1:fast:skiploopfilter=all.
- Broken file
- Try various combinations of -nobps -ni -forceidx -mc 0.
- Slow media (NFS/SMB mounts, DVD, VCD etc)
- Try -cache 8192.
- Are you using -cache to play a non-interleaved AVI file?
- Try -nocache.
Read DOCS/HTML/en/video.html for tuning/speedup tips.
If none of this helps you, read DOCS/HTML/en/bugreports.html.


And then the following just scrolls by:

A: 1.0 V: 17.5 A-V:-16.544 ct: 0.039 522/522 68% 98% 9.2% 519 0
Too many video packets in the buffer: (4096 in 8248628 bytes).
Maybe you are playing a non-interleaved stream/file or the codec failed?
For AVI files, try to force non-interleaved mode with the -ni option.
a52: CRC check failed!
A: 1.1 V: 17.6 A-V:-16.469 ct: 0.036 523/523 68% 98% 9.2% 519 0
Too many video packets in the buffer: (4096 in 8248632 bytes).
Maybe you are playing a non-interleaved stream/file or the codec failed?
For AVI files, try to force non-interleaved mode with the -ni option.
a52: CRC check failed!

Again, the video runs fine under Etch/Totem.
fwiw, I installed mplayer from slackbuilds and it installed fine.

Are your video driver and codecs working fully correctly on that system? Try the -ni option.

If you are still having trouble give vlc media player a whirl. There aren't any slackBuilds for it (yet), but there are binaries out there that are easy to find. 0.8.5 is linked from the downloads page on the vlc site. A newer binary can be found at slackware-current.net.

Between MPlayer and VLC I have never found a media file that I could not play.

Video playback works fine for me with Slackware on an old 333Mhz box with 192Mb of RAM when I use XINE. The same box running Debian is a non starter for video playback. I know on the PS3 mplayer won't work without dropping frames due to there being no 3D acceleration enabled so we have to currently use VLC there. This would suggest to me that your mplayer setup and/or the way it's been compiled is at fault. It's probably possible to compile mplayer so that it doesn't need 3D acceleration..., or you could enable 3D on the box if it isn't already.
Hope the ideas help you to find a working solution.

if you are using noatun kde player yes this could happen. use the gxine instead or mplayer. let me know

The program, as with a lot of Linux software, just handed you about nine different things to try. Did you try any of them?

I think the fix is explained in the error.

Yes

I will download vlc and try it. Till then, I have tried:
mplayer /dev/dvd
mplayer -nobps -forceidx -cache 8192 /dev/dvd
mplayer -ni -cache 8192 /dev/dvd
mplayer -mc 0 /dev/dvd


With all of the above, I now get video and audio. They just aren't in sync.

Here is different and complete output:

Playing /dev/dvd.
MPEG-PS file format detected.
VIDEO: MPEG2 704x480 (aspect 2) 29.970 fps 8918.0 kbps (1114.8 kbyte/s)
[VO_XV] It seems there is no Xvideo support for your video card available.
[VO_XV] Run 'xvinfo' to verify its Xv support and read
[VO_XV] DOCS/HTML/en/video.html#xv!
[VO_XV] See 'mplayer -vo help' for other (non-xv) video out drivers.
[VO_XV] Try -vo x11.
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 704 x 480 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
==========================================================================
==========================================================================
Opening audio decoder: [liba52] AC3 decoding with liba52
No accelerated IMDCT transform found
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, s16le, 256.0 kbit/16.67% (ratio: 32000->192000)
Selected audio codec: [a52] afm: liba52 (AC3-liba52)
==========================================================================
AO: [oss] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...
VDec: vo config request - 704 x 480 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [x11] 704x480 => 704x528 Planar YV12
[swscaler @ 0x88d8070]SwScaler: using unscaled yuv420p -> rgb32 special converter
VDec: vo config request - 704 x 480 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [x11] 704x480 => 704x528 Planar YV12
A: 4.3 V: 1.8 A-V: 2.453 ct: 0.098 51/ 51 134% 147% 26.0% 50 0

************************************************
**** Your system is too SLOW to play this! ****
************************************************

Possible reasons, problems, workarounds:
- Most common: broken/buggy _audio_ driver
- Try -ao sdl or use the OSS emulation of ALSA.
- Experiment with different values for -autosync, 30 is a good start.
- Slow video output
- Try a different -vo driver (-vo help for a list) or try -framedrop!
- Slow CPU
- Don't try to play a big DVD/DivX on a slow CPU! Try some of the lavdopts,
e.g. -vfm ffmpeg -lavdopts lowres=1:fast:skiploopfilter=all.
- Broken file
- Try various combinations of -nobps -ni -forceidx -mc 0.
- Slow media (NFS/SMB mounts, DVD, VCD etc)
- Try -cache 8192.
- Are you using -cache to play a non-interleaved AVI file?
- Try -nocache.
Read DOCS/HTML/en/video.html for tuning/speedup tips.
If none of this helps you, read DOCS/HTML/en/bugreports.html.

A: 16.2 V: 7.1 A-V: 9.142 ct: 0.106 208/208 93% 140% 16.3% 207 0
Exiting... (Quit)


Again, I'll try vlc or kaffeine and see what happens.
I also have to see what "[VO_XV] It seems there is no Xvideo support for your video card available." means. Card is Rage Xpert (128 Pro) and I'm using the r128 driver.

Gave that a try and so far:
error while loading shared libraries: libavformat.so.51: cannot open shared object file: No such file or directory.

That file isn't on this system and I haven't found it at packages.slackware.it or linuxpackages.net

but, I will keep looking.
I was given this computer 3 days ago, and this is my first attempt at watching video on it. I'm just trying to get it setup as a primary machine/system. It just irritated me when the video played on Etch but not Slackware.

Will keep trying for a while.

Thanks everybody for your help.

That library is part of ffmpeg, which has a lot of tuning options for CPU types.

Good luck figuring out which exact version they built it against or that the application expects. I'm using svn 10006 at home.

If you know it works on Etch, run the thing on Etch with some debug options enabled and maybe it'll tell you enough about what it chose to do so that you know what to tell the Slackware install to do.

I suspect you need to set up DRI support to get xvideo to work with that card.

I've had that too on this P3 (1000Mhz), but after a bit of Google'ing found that you have to compile MPlayer with --enable-runtime-cpudetection.
Did you try that?
If I'm not mistaken, the MPlayer Slackbuild script from SlackBuilds.org comes standard with that option.

That's where I got it from

This part is a bit suspicious:

Combined with the fact that you say you have no problems playing it inside another video player in another distribution, my guess is there is a problem with your Xorg configuration, so maybe you need to fix that and get the very needed Xv support. Video plays a lot better with the "xv" driver (from mplayer) than with the "x11" driver. The "x11" driver, which you are probably using, is very slow and unefficient, and should only be used in emergency situations.

I'm guessing it is a problem with your X configuration as well.

As far as your problem with vlc, did you use the version from Slackware-current.net? I have not tried that one as I am using vlc-0.8.5-i686-3from the vlc download page. I have not had the problem you are having with the libavformat.so, but I can play dvds and avi files just fine using it. libavformat.so does not exist on my system. Maybe the version from slackware-current is built differently.

Either way you should definitely make sure X is configured properly.