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Playback Slow/Choppy in Ubuntu 9.04?

Posted: 06 Jul 2009 08:02
by Eyeless Blond
Hi, I'm having a bit of a problem with playback in VLC. I've actually got a few video players installed (mplayer, the movie player that comes with Ubuntu, etc), but I generally use VLC because it handles subtitles the best. The problem is it's not handling the video decoding very well: unlike all the other players I try, VLC tends to stutter and skip frames, even long sequences when the resolution is 720P or higher.

Specs:

CPU: AMD Athlon X2 4850e
MB: MSI DKA790gx
GPU: HIS Radeon 4670 IceQ Turbo
OS: Ubuntu Jaunty 64-bit (Graphics driver: fglrx 9.6)

Is there anything I should try to fix this?

Re: Playback Slow/Choppy in Ubuntu 9.04?

Posted: 06 Jul 2009 11:17
by danwood76
What audio output are you using for VLC?
Sometimes the audio output can cause stuttering that looks like video effects. (this is probably magnified with HD video as it has 5.1 usually)

The default output is alsa, this can be a little buggy when compared to the pulse plugin. (which is available through synaptic)

Re: Playback Slow/Choppy in Ubuntu 9.04?

Posted: 07 Jul 2009 06:19
by Eyeless Blond
No joy. Even with audio disabled entirely the video still skips frames and displays all kinds of artifacts.

Any other ideas?

Re: Playback Slow/Choppy in Ubuntu 9.04?

Posted: 07 Jul 2009 06:21
by Eyeless Blond
On a side note, I do have pulseaudio installed, but I don't see the option in VLC. Is there something else I need to install so VLC can find it?

Re: Playback Slow/Choppy in Ubuntu 9.04?

Posted: 14 Jul 2009 14:37
by tg_drifter
Specs:

CPU: AMD Athlon X2 4850e
MB: MSI DKA790gx
GPU: HIS Radeon 4670 IceQ Turbo
OS: Ubuntu Jaunty 64-bit (Graphics driver: fglrx 9.6)

Is there anything I should try to fix this?
From the specs that you posted, I see that you have an ATI card. The current ATI driver seems to have problems cooperating with Compiz.
From my experience with two ATI cards (Radeon HD3650 and HD3850 which is pretty powerful), I have seen glitches when playing movies in windowed mode when Compiz was enabled.
Graphics-intensive applications such as games do not seem to be affected at all, but media players such as VLC and TVTime have problems.
I'd suggest that you disable all graphics effects (essentially disabling Compiz) every time you want to play a HD video. Give it a try and let me know if it helped.

Re: Playback Slow/Choppy in Ubuntu 9.04?

Posted: 18 Jul 2009 11:48
by Eyeless Blond
Oh yeah, I already know about that; Metacity all the way. I have to disable Compiz whenever I suspend/resume too. *sigh*

The 1.0 release seems to have solved most of my problems, actually. Now VLC and Mplayer seem to be roughly equivalent: Mplayer uses up more CPU, while VLC still has a bad habit of dropping the occasional frame here or there (though it's still almost night and day better now).

So, problem solved, or at least worked around. I really wish AMD'd get around to fixing fglrx with Compiz, and that Compiz would finally fix Suspend/Resume.

Re: Playback Slow/Choppy in Ubuntu 9.04?

Posted: 18 Aug 2009 10:09
by OttifantSir
I just found this out myself. A "revelation" you might say. I use a Radeon 3450 HD myself, streaming video over Gigabit LAN on a 2.4GHz 2GB RAM media-PC. I suddenly realised, out of the blue, that VLC is set to default video output, meaning X11/XVideo, but the card is capable of using OpenGL. So, I changed the output to OpenGL, saved the Preferences, restarted just to be sure that was the output used. Besides bad coding, skipped frames in the original recording, not the machine skipping frames, the video output has been stable, fluid and without artifacts. Just a tip to try if you have the possibility.