Kodi Community Forum

Hi!

The other day I got myself a new projector (InFocus X10) and directly enabled auto refresh rate by editing my xorg.conf and setting the switch in xbmc. When playing movies, the projector source information shows me that I in deed have 24Hz and I see that also in the codec information.

I then played some test clips to check that I had in deed eliminated the 24Hz juddering, but it seems I haven't. When playing the opening scene in Transporter 2, where the camera rotates it judders so much I almost get sick. I turn off the auto refresh rate and I can't see any difference. As I have read tests on the projector before buying it, they say that one of the benefits with this model is that it is pretty good at displaying 24Hz material without judder. So I'm completely clueless here. I don't know what could be wrong and I don't know how I could debug it. Any ideas or information is VERY appreciated!

Edit: I could add that I use an Asrock ION 330 for htpc and my xbmc version is svn 26018. I also have a A/V receiver between the player and the projector (Marantz SR 6003), but I have this set as pass-through, so it shouldnt' do anything with the signal.

Maybe I should also add that before I used another projector with this xbmc setup. I'm starting to wonder if this could have messed things up. That I have old settings somewhere for my old projector. If I check my xorg.conf, the vsync/hsync are for instance not matching my new projector. But I know to little about this, so I don't know if it affects a certain resolution/frame rate-kombo or just sets the limits for what modes I could use. I mean, I DO get 1080p/24hz out, so it seems correct, right? Could I somehow get it to rebuilt the xorg.conf for my new projector or does it do that automatically?

Here is my current config:
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder63) Mon Mar 23 15:33:27 PST 2009

Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "Module"
Load "dbe"
Load "extmod"
Load "type1"
Load "freetype"
Load "glx"
EndSection

Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Unknown"
HorizSync 28.0 - 33.0
VertRefresh 43.0 - 72.0
Option "DPMS"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "DynamicTwinView" "False"
Option "FlatPanelProperties" "Scaling = Native"
Option "NoLogo" "True"
SubSection "Display"
Depth 24
EndSubSection
EndSection

I've been thinking all day trying to figure this out and the only way my problem makes sense is if there is some transcoding from 24hz to 50/60Hz somewhere and then it is converted back to 24Hz. Does that make sense? Could this happen somehow with a combination of xbmc and/or my hardware setup? I mean, I DO get the correct signal type when checking the projector, so this is the only way I can explain it. But where would this stupid conversion take place in that case?

If anyone has the slightest idea or suggestion, please post it! Thanks!

What is XBMC tellling you about the framerate? (IIRC press O while playing a movie)

the_alien Wrote:What is XBMC tellling you about the framerate? (IIRC press O while playing a movie)

I don't have a keyboard connected, I'm using the iPhone remote so I'm not sure exactly what the O button brings up. But I guess that command is the same as the codec info button on that remote and that output shows a fps of a bit lower than 24 (guess the material is 23.976) as it should.

"O Displays CPU useage and video diagnostic information "
That showed me 25FPS when i had the judder problem with 24FPS movies. Don't know what the codec info button is

Did you activate the sync in the settings?
Tried the xorg.conf settings recommended for flat panel users? (can't exactly remember what it was)

the_alien Wrote:"O Displays CPU useage and video diagnostic information "
That showed me 25FPS when i had the judder problem with 24FPS movies. Don't know what the codec info button is

Did you activate the sync in the settings?
Tried the xorg.conf settings recommended for flat panel users? (can't exactly remember what it was)

Yes, that should be the same information. It shows stuff like cpu usage, skipped frames, fps and such. And it seems to be correct. I mean, I might have 23.976 source and play it in 24 Hz, but that would as I understand it only make it judder once every 41.667 seconds. So that's not the case. But I guess 25 fps would be a problem and as my projector doesn't support that, It would have explained it.

You mean the "Sync playback to display" option? No, I haven't tried that as I wasn't sure exactly what it does. I have googled it now and it seems interesting. I will at least try it when I get home. I guess this could affect my audio quality though, but if there isn't any other way...

Edit: One thing I'm wondering is, do I need to have mode lines in my xorg.conf. I see that there is a lot of discussions about what mode lines people should use. As I don't have any, I'm starting to think that maybe I should? What would be the difference? From where does X get the settings without that? EDID?

Could it be this?

Option "FlatPanelProperties" "Scaling = Native"

It looks like you've used the buildmeister xorg.conf ,but you have removed a lot of stuff from it . You need composite and twinview disabled for things to work properly.
Also enabling native scaling is a good idea as well.

And I can't see how you'll get 24fps when your vertical refresh is set to minimum of 43. I'm guessing your output will be 50Hz or maybe 60Hz.


Try this config which is the original buildmeister one with my data added to vert refresh+horiz sync ,and then change it to your specs. You need to look up the data on that projector.
You can probably remove the modeline altogether and let it auto detect. It's just that my TV is not reporting EDID properly (or isn't read properly in Linux..whatever lol) so I have to force it into 60Hz:

http://pastebin.com/m6c68a6b8


or if you need a modeline you can type gtf in a command line and make one that suits your setup.

You projector specs are here:

http://www.infocus.com/Products/Projectors/x10.aspx

it says:

H-Sync Range: 31.5 - 80kHz

V-Sync Range: 50 - 85Hz

enter those into the xorg.conf I provided and remove the modeline and see if it autodetects.

Judging from the datasheet I think it should output 24p as a multiple of 24 within the vertical sync range i.e. 72Hz. Also called 3:3 pulldown (kinda misleading name since it's not actually pulling down more like multiplying lol )

preppie Wrote:Could it be this?

Option "FlatPanelProperties" "Scaling = Native"

That was one of the settings i meant. That and
Option "DynamicTwinView" = false

Oh, sorry...I made a mistake when copy-pasting the file, I DO have a screen section as well. I have edited my first post now. As for the other tips, I will try it when I get home! In the meantime, thanks a lot!

UglyBob Wrote:Oh, sorry...I made a mistake when copy-pasting the file, I DO have a screen section as well. I have edited my first post now. As for the other tips, I will try it when I get home! In the meantime, thanks a lot!

Ok,now it looks more like mine

But your vertical refresh and horizontal sync are not correct according to the projector spec. Changing those should make things better .

cejstrup Wrote:Ok,now it looks more like mine

But your vertical refresh and horizontal sync are not correct according to the projector spec. Changing those should make things better .

Hope it does! It feels so bad to buy a new projector and then not get all benefits you were hoping for. I will try changing that values and also try sync to display if needed (but I'm guessing I might not need that if the other change works?).

Nothing seems to help. I get judder after changing the hsync/vsync, I get judder with sync to display (all variants, some of them only makes the sound "judder" as well). Don't know what to do...

Bob, check out this post and run through the various ideas there. Particularly, I'd recommend you try the triplebuffer option, but there may be other tidbits there that help as well. I can't guarantee it'll solve the problem, but it should allow you to rule out a few more things at the very least.

Good luck.