AVS Forum banner
Status
Not open for further replies.
1 - 12 of 12 Posts

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #1 ·
Nvidia forgot to include a very important step in the "CONFIGURING MULTIPLE X SCREENS ON ONE CARD" section of their README.txt. If you have two displays connected and you follow their instructions, it won't work and you'll get a very discouraging message:

Code:
Code:
(WW) NVIDIA(0): Multiple displays connected, but only one display allowed;
   (WW) NVIDIA(0): using first display
Of course you'll have no such problems if you use their "TwinView" which they highly recommend in the README.txt.


They forgot to mention that each Screen section in your XF86Config file needs to specify which display it will be using with the "ConnectedMonitor" option. For example:

Code:
Code:
Section "Screen"
      Identifier "SharpHDTV"
      Option "ConnectedMonitor" "DFP-0"

   :

   Section "Screen"
      Idenfifier "OldVGAMonitor"
      Option "ConnectedMonitor" "CRT-0"
With this, their X server will start up with no complaints and you'll have traditional dual X screens.


And if you're going to be using this for an HTPC, you'll want to do this instead of using TwinView. Xvmc and video overlays will not work on either display when running TwinView but they work perfectly on the first screen with multiple X screens. TwinView will force you to use software MPEG decoding and the video will have ugly tearing that will drive you nuts.


Another problem with TwinView is that X windows players get the display characteristics directly from X. Since TwinView creates a virtual display in a rectangle just large enough to fit the two combined displays, you'll have to do some trickery to get players like xine to use an 16:9 aspect ratio. The least worst way is to have TwinView create a virtual 16:9 display and manually specify where each display will be in it. Now everything running on the 4:3 display will have the wrong aspect ratio. And neither display will have Xvmc or overlays. No thanks.


There's one small annoyance with multiple X screens. Some players lilke xine don't have the traditional -display option so you'll have to set the DISPLAY environment variable to the screen you want it to use before you start it.
 

·
Registered
Joined
·
30 Posts
Connecting two CRT's did not require me to use 'Option "ConnectedMonitor". Might just be my video card. Use "export DISPLAY=:0.0" for screen 0 and "export DISPLAY=:0.1"for screen 1.
 

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #3 ·
Quote:
Originally posted by masters
Connecting two CRT's did not require me to use 'Option "ConnectedMonitor". Might just be my video card.
Or it could be a new "feature" in their recent drivers that they forgot to put in their README. Does your card support "TwinView"?
 

·
Registered
Joined
·
30 Posts
Yes, its a new FX 5200. Maybe the default is CRT. I didn't try TwinView because your excellent post says I shouldn't bother. The hard part is the xine post-processing. I have it working but knowing what to use the problem.


What's the easy way to lock the refresh rate to 72Hz?
 

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #5 ·
I think I have an Geforce FX 5200 too. I wonder if my driver is a little old. I haven't built a new kernel in a while so I wouldn't have seen any updates.
 

·
Registered
Joined
·
3 Posts
Man! I had this exact problem about a month ago. I had a dual head PCI FX 5200 card that I had previously used as two X screens (no Twinview). I built a new desktop intended to be triple headed. I put in two FX5200 cards, the dual head pci one and a single head AGP one. I then proceeded to get the latest NVidia driver (1.0-6106). I couldn't make the two screen method work with the pci card no matter what. I googled that error message about "only one screen allowed" , scoured AVS and deja and anywhere I could think of. Using twinview worked fine.. but with the caveats already mentioned. I finally gave up, resigned myself to no triple head desktop, and swapped in an old dual head matrox G450 and removed the FX5200 pci.


I made up for no triple head by setting up the synergy package from synergy2.sf.net with sun blade 100, a windows box, and my linux box.


so it's psuedo quad head now....
 

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #7 ·
I found the solution on the nvnews.com boards. Someone happened to mention it. A couple of people mentioned that they had figured it out but didn't bother to say how or what board they were using. And there were some red herrings like needed to start the X server from the command line with startx. I was pretty sure it was something that Nvidia had broken since they rave about how wonderful TwinView is in their documentation.


I've emailed Nvidia asking them to add this info to the README.txt. The error message really makes it seem like it's just not possible to do this with the board and you'll just have to use wonderful TwinView. If that were the case, I'd be looking for another card.


Fortunately it does work and it's a perfect solution for a Linux HTPC.
 

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #8 ·
I tried updating my Nvidia driver from 1.0-4498 to 1.0-6111. Suddenly my LCD monitor won't work at all claiming to be receiving an unsupported resolution. I switched back to the 1.0-4496 driver and everything works great again.


Can you believe it? Of course you can!
 

·
Registered
Joined
·
3 Posts
On the bright side, last night i successfully got a fx 5200 with the 6111 drivers working with a 1080i modeline to my hdtv. This is an improvement over the previous drivers which didn't do interlaced 1920x1080 (as far as i ever found out).


I also rebuillt the mplayer src.rpm from freshrpms and enabled xvmc vo device, but a couple attempts to use -vo xvmc with hdtv recordings and divx movie files failed to work. ... some error about codec is not compatible with selected -vo device. I was busy messing with dvb drivers and apps and didnt' pursue the xvmc problem (yet). I never fiddled with xvmc previosuly so I know little about what ever worked or didnt'.


I get fairly regular dropped frames (mplayer -framedrop) with a athlon 2400 playing a hdtv recording. I was wondering if xvmc would make a difference, and if it would handle hdtv resolutions.
 

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #10 ·
Yes, xvmc makes an enormous difference. It cuts my CPU usage in half (I'm running an Athlon XP 2700 at 2.166 Ghz).


I've had some problems with it. It tends to be more jumpy at times, especially with 60fps sources. Also it's worthless with my local WB station. Whereever there's no motion, the image has awful vertical lines. Both of these sources look fine with xv.
 

·
Registered
Joined
·
3 Posts
You're right... xvmc is the answer I've been looking for for some time now. I'd always assumed it was enabled... but I usually had so many other problems I was fiddling with, enabling xmvc was last on the list... sort of like infrared remote control in X, it was last on my list once I got eveything else worked out.



My final issue turned out to be that I had the svideo output hooked up to my tv which was also giving that infamous error:


"Multiple displays connected, but only one allowed;"


then mplayer would quit (gracefully) when trying to use -vo xvmc


with no xvid hooked up, the X log was clean and when I played back that hdtv recording... I was in disbelief... ~49% cpu utilization with 1920x1080i display and 1920x1022i size recording without a single dropped frame . Previously it was 70% mplayer and 30% X utilization with probably at least 10% dropped frames.

(both with Athlon XP 2400+, FX5200, 1GB ddr266 )


poor playback performance (and money:) ) was basicaly all that was stopping me from buying a pcHDTV card.... although now they are out of stock and awaiting the new model pcHDTV-3000.
 

·
Registered
Joined
·
10,688 Posts
Discussion Starter · #12 ·
Yes that's about how much CPU I use with XvMC watching 1080i material. The hardware also does deinterlacing (I think it supports three or four methods) and that's a big bonus for 1080i.
 
1 - 12 of 12 Posts
Status
Not open for further replies.
Top