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View Full Version : Two Separate Instances of X on Dual Card


misleb
12-04-02, 09:41 PM
Hello,

I've been a happy Linux/TNT2 user for a couple years now. I'm ready to upgrade and I also want to experiment with with dual ports and TVOUT. I have read docs on setting up TVOUT, Twinview, and Xinerama. But I am not sure if it is possible to use the two video outputs (on a single card) independently. That is, i want to run two different X sessions. One that displays a PVR application (via X) to the TV and one that is a regular X desktop.

My guess is that all I have to do is maintain two different XF86Config's, each referenceing a different "BusID." Is this correct? Do the dual head NVIDIA cards have two different BusIDs?
Or maybe I can simply have one instance of X running that maintains each head as an independant display. But doing it this way, I have the problem of not being able to logout of my X desktop without killing the TVOUT.

Can someone recomment a good brand/model with TVOUT and dual ports? I was looking at the Geforce 2 MX 200 chipset, but there are so many different manufacturers. Some with dual head, some with TVOUT, some without.

Thanks,
-matthew

qjm
12-05-02, 12:05 AM
I believe that it is not possible to run XFree twice on the same card. There is only one BusID -- for some graphics things there is only one pipeline so the option is "clone", or "more"=Twinview where X sees one huge letterbox and does not know about the two monitors. Twinview is the only option for a single card. Xinerama and a second X only works with a PCI card.

You can however have a TV and a desktop using twinview, BUT the TV will be a desktop. Xine will fullscreen to a single monitor but any windows behind it will disappear. As you mention you will not be able to logout without losing the TV functionality. Generally for home machines this is not a big deal -- but I guess you could always put on a screen lock or have a "TV" user.

Q.

misleb
12-05-02, 08:43 AM
Well that sucks. Are there any NVIDIA cards that have two pipelines? I'm doing this in a Shuttle machine with only 1 PCI slot and 1 AGP slot. I can't use a second video card (TV tuner in PCI and G2MX in AGP).

How would I get xine to run exclusivley in the TVOUT area of the desktop? I would also like to at least put some edge resistence between the two areas as well. Is it possible to make it feel like they are two different heads to the user? I don't need my mouse, focus, or other programs to ever go into the TVOUT area. Perhaps there is a way to tell the Window manager to just use a specific portion of the desktop and have the PVR programs run outside of that area. I seem to recall doing something like this in Windows where you play a movie and it shows strictly on the TVOUT area and the desktop doesn't extend there..

Then again, this machine does have a built in AGP video that is "disabled" when using the nVidia AGP. Is it possible to actually use the built in AGP card as my desktop and the Gefore2 for TVOUT (although it would be a waste of GPU power). I would assume that AGP is a bus like PCI and can support multiple devices. Or is AGP strictly for single devices/BusIDs?

-matthew

qjm
12-05-02, 06:22 PM
The two pipelines is an intrinsic feature (maybe Quadro highend really $ cards do).

I forgot about nvtv!!! Have a look at the nv-tv-out project on soureforge. This may well do what you want wrt tv out. xine and mplayer support this if you have the daemon running.

Q.

abbe
12-07-02, 09:00 PM
Does anyone know if this will be supported in future version of the linux driver?