24Hz judder problem
#16
Ok, thanks for the tip! I have at least created me a log now and looked around a bit. I don't know, but it seems it is the A/V receivers edid information it gets. For instance, the frequency information says:

(II) Jan 28 00:43:02 NVIDIA(0): Frequency information for MJI SR6003 HDMI1 (DFP-0):
(II) Jan 28 00:43:02 NVIDIA(0): HorizSync : 16.000-69.000 kHz
(II) Jan 28 00:43:02 NVIDIA(0): VertRefresh : 43.000-85.000 Hz
(II) Jan 28 00:43:02 NVIDIA(0): (HorizSync from EDID)
(II) Jan 28 00:43:02 NVIDIA(0): (VertRefresh from EDID)

As cejstrup said before, the frequency range for my projector is:

H-Sync Range: 31.5 - 80kHz

V-Sync Range: 50 - 85Hz

Could this be a problem?

I will try without my receiver just to see what happens after work. If it works, I guess I have to create my own mode lines to override what the receiver says? One would think that it should just pass the information from the display and not it's own information or is it the receiver that limits what kind of signal I could use?

Also I'm wondering, if you have a certain resolution and a certain refresh rate, does that mean you always have a certain hsync/vsync? I'm guessing I could not have 1080p@24hz with the wrong hsync/vsync, right? So if my projector says 1080p 24hz, how could it be wrong?
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#17
Yes,it could be a problem. The receiver doesn't pass the correct EDID information.

Manually creating modelines that fits within your projector's specifications would be the next thing to try out.

This tool can generate them:

http://amlc.berlios.de/
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#18
and you can try to grab the correct EDID Information from the NvidiaControllpanel and add them to you Xorg.conf as file .. this was the only way for me to get my LCD working properly. Just do a search for custom EDID files & Xorg.conf

of course you need to attach your projector directly to the htpc
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#19
UglyBob Wrote:Also I'm wondering, if you have a certain resolution and a certain refresh rate, does that mean you always have a certain hsync/vsync? I'm guessing I could not have 1080p@24hz with the wrong hsync/vsync, right? So if my projector says 1080p 24hz, how could it be wrong?

You could still be having problems related to Nvidia driver's believing that that 24hz mode is incompatible. On mine, before I manually changed to include 24hz in the range of support syncs, I would find error messages in the log. It's best to get it right as otherwise you can't guarantee xbmc is going to find the right refresh rate and modeline that you intend for it to. (i.e. on mine, before I made the change, it would ignore my custom modeline as invalid and then default to some other 24hz mode that it seemed to find more acceptable). Definitely not what you would think would happen, so it's worth looking at.

Also, trying it at first with the projector directly connected would seem to take out the receiver as a variable in the problem. If you can't get it working that way, I'd recommend you consider starting with a direct connection, getting it working, and then plug into the receiver and figure out what is changing.

Interestingly, when I ran the verbose X log command, I got different results when plugged into the projector directly vs. through the (supposedly) passthrough receiver. In the end it worked fine through the receiver, but I found it odd that the receiver would return different results than the projector.
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#20
OK, that's interesting! I will definitely try all of your suggestions tonight, starting with removing the receiver! Thanks once again for all your help!
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