Trick to prevent flickering in vlc

[symzo]

Hello,

I've made a small discovery today :-P. I don't know how or why it works, but it makes flickering disappear completely in VLC using Xvideo. The idea is to ask Xvideo to output on another display.

This is what I did :
In VLC, I went in :
Settings > Preferences
There, I enabled "Advanced options" (bottom right). Then, I went in :
Video > Output Modules
There, I chose Xvideo as the output module
Then, I went in the options of Xvideo :
Video > Output Modules > Xvideo
And I entered ":1" as the X11 display.

That's it. When I start a movie, there's a certain amount of time before the image appears, but it's not flickering at all, which is nice.

I'm quite surprised, since I am supposed to have only one X server running, and since VLC is running on display :0.0.

Can someone explain this behaviour ? ;-)

[adamk]

Since vlc can't connect to display :1, it's probably passing up the Xvideo output device and falling back to the x11 one. You could achieve the same results by simply selecting the x11 output device.

Adam

[symzo]

Ooops :-P

You are right, I hadn't realize that X11 had become fast enough : on my computer, the framerate has become quite decent.

I learned something today :-).

Thanks.

[Thetargos]

I'm not sure if others have noticed this, but there is no flickering when the videos are run at fullscreen with XVideo turned on. Windowed, though it flickers like heck.

[djdoo]

I'm not sure if others have noticed this, but there is no flickering when the videos are run at fullscreen with XVideo turned on. Windowed, though it flickers like heck.

You can bet on that my friend...
See our thread for fglrx at Compiz-Fusion forum http://forum.compiz-fusion.org/showthread.php?t=6794 and you 'll understand... Cause for us the problem is permanent and it can be solved only fullscreen, XV video windowed flickering can be caused be any Window Manager that uses Compositing stuff...

[Thetargos]

You can bet on that my friend...
See our thread for fglrx at Compiz-Fusion forum http://forum.compiz-fusion.org/showthread.php?t=6794 and you 'll understand... Cause for us the problem is permanent and it can be solved only fullscreen, XV video windowed flickering can be caused be any Window Manager that uses Compositing stuff...

I've only started to gather information on this since I got this laptop with the X1200. At any rate, I have not seen this happen with video and Intel GPUs (open drivers) or nVidia drivers. I don't know if the open source Radeon drivers also suffer from this.

[djdoo]

I've only started to gather information on this since I got this laptop with the X1200. At any rate, I have not seen this happen with video and Intel GPUs (open drivers) or nVidia drivers. I don't know if the open source Radeon drivers also suffer from this.

Practically you can only use fglrx for X1200... And yes if Compositing stuff is used the open drivers get this problem too.

It will only be solved with DRI2 but right now it is only usable for intel GPUs...

[Thetargos]

The question is what do Intel and nVidia drivers do so that this doesn't happen. What is missing from flglrx and open Radeon drivers that will only be fixed with DRI2? (I'm sorry if I'm talking about something utterly obvious that I have not checked out yet).

[adamk]

The question is what do Intel and nVidia drivers do so that this doesn't happen. What is missing from flglrx and open Radeon drivers that will only be fixed with DRI2? (I'm sorry if I'm talking about something utterly obvious that I have not checked out yet).

Unless you are using the intel driver from the git development tree, it does happen with the intel drivers. The nvidia drivers are the only ones that handled Xvideo in a composited environment properly from the beginning. Now that this has been fixed in the intel driver, all the open source drivers will hopefully fall in line... And since DRI2 was not required for the fix with the intel driver (it was fixed before DRI2 was merged into the X server), it's probably not required for the radeon driver either.

[Thetargos]

Yes, I saw this with the Intel git driver.