Linux HOW-TO achieve perfect playback at 23.97 or 59.94 Hz with NVIDIA GPU hardware

I think I solved it. It looks like an issue with 24p and the 100hz motion plus settings. Which I should have known to check first
Anyway after playing with all the TV settings I seem to have got it running nice and smooth again.

My current build is Eden on Ubuntu 12.04. My hardware is as follows:

Case: Foxconn Case / Mobo
CPU: Intel Pentium Wolfdale E5700
GPU: Nvidia GeForce 8400GS
RAM: GSkill 2Gb

I have so far been unsuccessful in getting the GeForce card to dispaly 24hz. I have all the latest Nvidia drivers in place. I have tried running the script manually (with lightdm in place of gdm) but after putting the new Xorg file in place, my system hangs at boot until I replace with the original Xorg.

The step of the process that is supposed to provide a text file of all the modelines from Xorg.0.log does create a text file but with nothing in it. After digging down and finding my Xorg.0.log, there is not "modelines" listing similar to Jum Jum's post. I am getting the feeling we are comparing apples to oranges. See my log below:

http://pastebin.com/embed_js.php?i=D6TnEVVv


Is this instructional not applicable for 12.04? I am 100% sure my television can handle 24hz as I have a Revo build that switches between 60 and 24 no problem. Any ideas?

Thanks in advance,
Rob

Ok,

I was able to get the nvidia.sh script to run all the way through. Now when playing content (settings are "sync to display" and "change refresh rate") the codec info reports 24 hz with 23.97 fps. The judder now appears worse than before though .

One other thing of note. My Revo actually does change my Samsung TV to 24hz correctly. This build though when I fire up a movie and it reports the info above, the TV remains in 60hz. Would this cause the now noticeable judder?

I feel like I am just missing something ever so slight here. Also, sorry for the newb question, now how are you guys posting your pastes? I'd like to throw up my Xorg.conf but I feel that I failed in my last post.

Rob

I'm also fighting this in Ubuntu 12.04, NVIDIA drivers 295.40 and 302.17, XBMC Eden.
I was able to modify the script that it works, the problem is, the driver seems to ignore the Option "ModeDebug" "true", there are no modes in xorg.log, only this:
No modes were requested; the default mode "nvidia-auto-select"
will be used as the requested mode.
Validated modes:
"DFP-0:nvidia-auto-select"

The modes.txt file is empty.
I was able to extract the modes from OpenELEC. I have added the needed modes to xorg.conf but they seem to be ignored by the driver.
I'm not able to switch resolution even in Ubuntu to something else than 1280x720_60 = nvidia-auto-select.
Playback in XBMC stutters badly.
I'm stuck.
Has anyone any ideas how to solve this, please?

The only way to achieve perfect playback of 23.976 with NVidia on Linux is to define a custom modeline. With EDIT you'll get 23.971.
Driver 302.17 can distinguish between 23.97 and 24 Hz because it has support for xrandr 1.2 and 1.3. No need to set meta modes or modes in the Screen section. I am running 302 with this modeline in Monitor section:


and those Option in the Screen section (otherwise the modeline would be ignored)

i had to modify the script too to run on 12.04. My modifications:

Lines 50 & 51, change gdm to lightdm

Line 59 (this might be the one you need) change "cut -c32-" to "cut -c31-". It was truncating the first character of each line of the edid.

With those changes the script ran flawlessly here.

Sorted it out removing the NVIDIA driver, deleting configs and reinstalling again.
I had to disable EDID and add modelines because my TV support 1080p24 but this mode is not in the EDID.
The last problem seems to be NVIDIA removed the "FlatPanelProperties" "Scaling = Native" option from 302.17 driver.

Hello,

I've following this post and the guide, and I was able to set xbmc to run in 23.97fps really well, but my problem is that If i set everything to work through the GPU I loose the HW acceleration on ubuntu desktop.

This is my xorg.conf


Testing the diferent opcion, as I'm not an expert in xorg, I've noticed that the problems seems to come from Section "Extensions" -> Composite. If I comment this part, HWacceleration in desktop works but with "artifacts" and mouse some times loose the draw but when I try to run a 1080 movie in XBMC hwacceleration is not working and all i managed by the CPU.

What I should do? Because, I would like to have hwacceleration in both, but I don't know how to achieve it.

Thanks

You can't have it both ways. For XBMC to work well, compositing needs to be turned off. For eye-candy on the desktop, it needs to be turned on. At best, when you want to switch to the desktop, you can kill X, enable compositing in xorg.conf and then restart X. To go back to XBMC, you could reverse the process. This could all be scripted to work with a single command, but it needs to be a workaround.

Is there an equivalent guide like this for Windows?