Custom display resolution

[sp00n]

Hi boyz and devz

My question is regarding the possibility to add custom display resolutions to our hdmi sticks.

I have an old Philips monitor with 1440x900 resolution which cant handle the 720p @ 60 or 50 hz.
Besides that I have an Optoma HD66 projector which can turn on 3D only at 720p@120 hz.
In windoze i used hacked .inf file with addition EDID info added which allows me to enable this resolution. But here I don't have a clue how to do it. Is there a chance to edit some entries in corresponding files at boot in order to enable new resolutions or this should be compiled in kernel?

Sorry if my questions sound too stupid but I am a real newbie in android and have a little experience in linux.

Thanks in advance for your answers

[JDfense]

Your questions are absolutly not stupid.
I learned so fare, the resolution would be adjusted in the kernel, but sorry, it is over my abillities to do it.

JDfense

[sp00n]

Thanks JDfense ... I guess we probably shall ask for help bob, leolas, neomode or other from the top devs here.

[Finless]

You do not say what stick you have. If you have a MK808 Omegamoon's kernel might support your needed resolution. Other than that, no kernel sources, no custom resolution.

Bob

[sp00n]

Hi Bob,

I have a chinese clone of UG802 called S19C - http://www.ahappydeal.com/product-113736.html (not sure if its ok to post links to merchants , i will remove it if necessary)
Already tried pretty much every other available rom for Rikomagic RK3066 based devices and also Minix G4.
Most of them work without problem, only the realtek 8188 driver needs to be compiled for wifi to work.

Other than that I think your UG802 rom 1.8 was the best available for this device.

[kong76]

This is a screenshot of my mk808 1080p kernel with android UI canvas resized to 640x480. As you can see "am display-device 640x480" definitely works. Any resolution I have tried have worked provided is was not bigger than the visible framebuffer size.

Since hdmi output mode requires the video mode to be declared inside the kernel a custom resolution will involve patching an unused video mode in the kernel I guess. 720x480 on 2dark4u's kernel would be my candidate to be replaced with whatever mode is desired. Stock kernels would have to lose either 720p or 1080p, whichever the kernel is not using.

The big obstacle is resizing the framebuffer itself. The UI composites itself on the framebuffer which is created at boot time. I would have to dig deeper for this. I can tell you right now that my kernel creates a 32-bit fb0 for the UI and a same size 16-bit framebuffer (fb1) for the mouse cursor. Note how the cursor overlay it is a full screen framebuffer unlike other devices (amlogic) where the cursor is painted on a small framebuffer which is panned around to the desired position when composited.

The mouse cursor bounds remain constant to the whole framebuffer even if you resize the UI as in above screenshot. The cursor image is clipped to the UI area and is not visible outside but it actually moves behind the black outher bounds rather than staying within the visible UI area.

I do believe it is actually possible to have custom resolutions with more research into changing framebuffer size. Not sure if I will have time to do more research but I will keep people posted.

[sp00n]

@ BOB,

Thanks again mate !

Just flashted your 1.8 rom for UG802 with Omegamoon kernel DVI 720p and voila I got the monitor working at 720p. Sadly no WiFi but no big deal. The point is - its working.
Probably will write in Omegamoon's blog with request for other custom res added to kernel.

@ kong76

Thank you for your detailed answer. Kinda got the idea for patching the unused resolution settings in kernel but unfortunately I am really way behind you in understanding how the framebuffer size works. But anyway thanks again. I am pretty sure some advanced users will find this info very useful.

[neomode]

AW: Custom display resolution

If I know right omegamoon has discovered a way to set customer resolution on boot. Let me see where I found it.

Neomode Freaktab.com Developer

[Guest]

Hi Neomode, did you found that option ? I really need to be able to set a custom (1024x768) resolution on my MK808B.... I'm seeing everything with the wrong aspect ratio right now....

Thanks.