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Resolution not selectable because of monitors DDC

#1

… not really a bug but something that i think does not make any sense - so i decided to post it here.

Switching output of Renderer (EX9) to custom resolutions or refresh rates normaly was and should not be a problem since beta9. Until yesterday my my experience was that any resolution you can customize in the display driver or powerstrip shows up in Inspektors pull down menus and can be selected.

But yesterday I was not able to set vvvv to any custom resolution that worked perfectly with the windows desktop. After some time (grrrr) i found out that the difference was, that the first time ever I had standard monitors sending DDC-data (Display Data Channel) connected directly to the graphics card - so the graphics card was receiving DDC from the monitor.

As soon as the graphics card is receiving any DDC from the monitor it seems that you are only able to set the Renderer(EX9) to the resolutions and refresh rates DDC is recommending (proof me if i am wrong). If you cut of Pin12 of the VGA-cable (Pin 12 is used to transmit DDC) you are (after reboot) again able to select any resolution available under windows.When no DDC is received you can select “Default Monitor” in the graphics card driver otherways only “Plug and Play Monitor” or a more specific monitor.

I think, this behaviour does not make any sense at all. Maybe vvvv is only reading these “allowed” graphics card system from the wrong “registry” - instead of reading the under windows possible settings !? In my eyes VVVV should at least offer all settings possible under windows and not only the ones “allowed” by the monitor manufacturer.

Markus

#2

this sounds like completely annoying. i have seen graphic card drivers who explicitly allow you to select if DDC shoudl be used or not. what cards did you use?

but to add an probably unrelated bug to that observation:

it happened to me that when i select a valid fullscreen resolution or frequency in the inspector this value gets not displayed as the current setting of the renderer.
when i change e.g. the backbuffer count pin, the value will appear suddenly. any ideas? i never experienced that before beta10

#3

thanks markus for sharing that interesting information. i’m afraid there is nothing we can do against this problem. vvvv is asking the directx-api for display capabilities. in return it gets a list whose values it can then use to go fullscreen. if vvvv uses any other settings than returned by the directx-api there comes an error.

@oschatz:
i don’t get that…you mean like an enum display update problem?

when i change e.g. the backbuffer count pin, the value will appear >>suddenly.
please try to rephrase that.

#4

@joreg: yes, an update problem. take the fullscreen resolution pin. i can select an enum value in the pulldown, but when i release the pulldown, the value which i selected is not displayed as the current value (i had also the feeling that that value was not used, but did not take the time to reproduce that)

the value which was originally selected shows up later when i eg change the backbuffer count pin

#5

Just out of curiosity - Will Powestrip override the DDC setting? I’d think that once you force the card to use a non-registered freqency, it might switch to “ignore DDC” altogether.
Quite certainly this is the case with DVI connections, as these also do VESA DDC support, and we’ve just had a similar situation.

#6

@oschatz. understand, but cannot reproduce.

#7

It is not the card, that is having the problems with the DDC.
In almost every driver you are able to override the DDC.
It is only a problem of VVVV or directx.

A strange detail:
If you have two monitors connected to the two heads of the graphics card - one with and one without DDC, you can for exmple if the render is on the “No DDC-side” select 50Hz vertical on this adapterbut not on the other. But if you you move the “50Hz-Renderer” from the non DDC-side without any changes to the DDC-side and than switch to fullscreen, fullscreen works with 50Hz !?

Markus

#8

any news on this?

I’m having the same issue (again). Last time it was strangely solved by switching the physical output on my GC and switch them back in the driver. But this doesn’t work now.

Setup:
One grafic card for patching as primary screen. two more grafic cards for the projectors. two renderers in dual span mode (2048x768) in fullscreen mode. The projectors are connected via 5 BNC-connections routing to little amps. from there via VGA to a VGA-DVI adapter and in the GraCa-output.

The resolution of both renderers is set to 2048x768 and the patch saved. After restarting the patch, the resolution of both renderers are set back to 1024x768 and the image is scrambled. Also if the patch is saved and re-started with the correct resolution in windowed mode switched to fullscreen via pin manually.

I’ve tried the “switch physical outputs” trick but no success.
Shall I start cutting some pins ???

z.

PS.: My post would probably have been better located here.

#9

following a fine hint from the worlds tallest patcher, that’s what solved my problem:

I re-organized the cables to the grafic cards physically

  • set Fullscreen outputs to GraCard 1 and 2
  • set patching screen NOT set as primary screen

After restarting I had to re-collect all my sub-patches manually in the XML file as they where stored with funny coordinates…
Now fullscreen works as expected.

#10

Though I’d update this thread.

I was able to achieve tricking the system by removing pin 12 from my VGA cable and setting a custom resolution using RivaTuner. Now able to get 6144x768 (6x 1024x768, 2xtripplehead2go’s) as a possible resolution inside of vvvv even though nothing other that a normal monitor connected to it.

Was having trouble getting full 6144x768 on my client machine when only using a single display on my server machine. sorted and happy now! thanks MSBERGER for the tip removing pin 12

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