pobalopalous
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Apps known to support dual display

Mon Nov 16, 2015 11:12 pm

The https://www.raspberrypi.org/blog/the-ea ... i-display/ announcement makes it clear that only certain apps will be able to take advantage of the HDMI dual display. It goes on to give an example which works great:
omxplayer --display=5 video.mkv

Is there a list of other apps that are known to work with the touchscreen and the HDMI display?

I'm particularly interested in a browser that can be launched fullscreen on the HDMI display.

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DougieLawson
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Re: Apps known to support dual display

Mon Nov 16, 2015 11:32 pm

There's no reason to assume Günter Kreidl's kweb/kweb3 won't work.

A more interesting list would be things that DON'T work on the official display.
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pobalopalous
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Re: Apps known to support dual display

Tue Nov 17, 2015 12:21 am

DougieLawson wrote:There's no reason to assume Günter Kreidl's kweb/kweb3 won't work.

A more interesting list would be things that DON'T work on the official display.
Hmmm. I'm must be missing something obvious then. Of course --display=5 is an option for omxplayer. I can not see a similar command line option for epiphany or kweb/kweb3.

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AndyD
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Re: Apps known to support dual display

Tue Nov 17, 2015 1:01 am

There is very little software that will run on the second display on a Raspberry Pi. The issue is that the second display, doesn't have a framebuffer device and so can only be used by software that interfaces with the Raspberry Pi compositor/DispmanX. This does include software that is written for the Raspberry Pi that uses OpenGL ES, Open VG etc, as long as you can pass a display number into the software. I am not aware of any browser that meets these requirements.

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DougieLawson
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Re: Apps known to support dual display

Tue Nov 17, 2015 9:21 am

Try adding

Code: Select all

display_default_lcd=0
to /boot/config.txt
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pobalopalous
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Re: Apps known to support dual display

Tue Nov 17, 2015 9:27 am

AndyD wrote:There is very little software that will run on the second display on a Raspberry Pi. The issue is that the second display, doesn't have a framebuffer device and so can only be used by software that interfaces with the Raspberry Pi compositor/DispmanX. This does include software that is written for the Raspberry Pi that uses OpenGL ES, Open VG etc, as long as you can pass a display number into the software. I am not aware of any browser that meets these requirements.
When epiphany was released it had some use of DispmanX but perhaps that was just for video playback. I can not easily find any documentation on that but I'm probably not looking in the right places.

But getting back to the original question, and rephrasing based on the responses so far:
Is there a list of applications that uses DispmanX / OpenGL, etc and which ones provide an option to pass a display number into the software?

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AndyD
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Re: Apps known to support dual display

Tue Nov 17, 2015 9:31 am

DougieLawson wrote:Try adding

Code: Select all

display_default_lcd=0
to /boot/config.txt
The OP wants to use both the Official Display and a monitor/TV attached to the HDMI port of the Raspberry Pi. Yes, you can select which of the two display gets the single framebuffer device, but you can't have two framebuffer devices. AFAIK to have two framebuffer devices requires some work to be done in the firmware and the Linux driver.
Last edited by AndyD on Tue Nov 17, 2015 10:44 am, edited 1 time in total.

ghans
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Re: Apps known to support dual display

Tue Nov 17, 2015 9:42 am

Exactly.

So far i know this limits users to Kivy , Kodi and omxplayer. There was a new enviroment variable for other dispmanx apps too - i just can't find the thread now ...

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AndyD
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Re: Apps known to support dual display

Tue Nov 17, 2015 10:55 am

ghans wrote:Exactly.

So far i know this limits users to Kivy , Kodi and omxplayer. There was a new enviroment variable for other dispmanx apps too - i just can't find the thread now ...

ghans
I had a look in the userland repository ... it is VC_DISPLAY. The only reference I could find to it on the forum is here.

pobalopalous
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Re: Apps known to support dual display

Tue Nov 17, 2015 8:38 pm

AndyD wrote:
ghans wrote:Exactly.

So far i know this limits users to Kivy , Kodi and omxplayer. There was a new enviroment variable for other dispmanx apps too - i just can't find the thread now ...

ghans
I had a look in the userland repository ... it is VC_DISPLAY. The only reference I could find to it on the forum is here.
Thanks for the contributions so far folks. For me, the goal is to have a browser in kiosk mode full screen rendered on HDMI and the desktop displayed on the LCD touchscreen. I have been unsuccessful with using VC_DISPLAY as an env var with epiphany to achieve this.

Wietse
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Re: Apps known to support dual display

Wed Jan 06, 2016 10:58 am

We are trying something similar to what pobalopalous is also trying to achieve. We have two television screens, one connected through Gert's VGA666 port and one on the HDMI port of the raspberry. Currently everything works fine when we play a stream/videofile on the VGA connected TV with omxplayer and using the "--display 4 " variable. However, we want to show a webpage on that TV that is connected to the VGA port and another website on the TV that is connected to the HDMI port, simply said a "dual screen" situation with two TV's showing a different webpage. Is there a way to achieve this currently?

EllipsenPark
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Re: Apps known to support dual display

Wed Jan 06, 2016 5:08 pm

Would it be possible to use the generic tty console on dual screens ?

ghans
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Re: Apps known to support dual display

Wed Jan 06, 2016 8:08 pm

So far i know , that is currently unsupported as well.

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EllipsenPark
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Re: Apps known to support dual display

Wed Jan 06, 2016 8:24 pm

Is there a chance it will ever be supported ? It'd enhance the usefulness by a great amount, really ...

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karrika
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Re: Apps known to support dual display

Thu Jan 07, 2016 5:40 am

For small embedded computers use of osc/twisted for communicating between apps sounds like a better solution. Here one app can control one display only. But through osc the apps can communicate and for the user you have the feeling of controlling the system from multiple screens.

There is other threads of how to use USB for fast communication between PiZero and Pi 2. Allocating a PiZero for the 2nd display would also give more memory and one extra core.

QLC+ already supports OSC for controlling lights from a tablet or mobile phone. So there is more than one way to split the GUI into several monitors.

I don't believe that the Pi's have the power to render two screens simultaneously.

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Re: Apps known to support dual display

Thu Jan 07, 2016 8:21 am

So as mentioned in this and other posts, kivy should support dual display, so for example output to the official display, and also to the hdmi output.
I am working on a kivy based GUI that also connects to my DSLR. It would be useful to have the GUI on the 7" display and an image downloaded from the DSLR on a hdmi screen. Any resource or examples available anywhere?

Texy
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https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

Wietse
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Re: Apps known to support dual display

Fri Jan 08, 2016 8:30 am

Hi texy, thanks for your reply, but I am slightly lost, how do I use Kivy to show a webpage on tv 1 (via Gert's vga 666) and another one on tv 2 (via hdmi)? Currently I am able to play a video on tv 1 (using omxplayer --display 4) and browse webpages on tv 2 at the same time and everything runs smooth, no heavy processor load. So I would expect that it should be possible with the hardware, it is just a matter of how to set-up the software.

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Re: Apps known to support dual display

Fri Jan 08, 2016 9:03 am

Wietse wrote:Hi texy, thanks for your reply, but I am slightly lost, how do I use Kivy to show a webpage on tv 1 (via Gert's vga 666) and another one on tv 2 (via hdmi)? Currently I am able to play a video on tv 1 (using omxplayer --display 4) and browse webpages on tv 2 at the same time and everything runs smooth, no heavy processor load. So I would expect that it should be possible with the hardware, it is just a matter of how to set-up the software.
This thread was in reference to using the Official Touch Display with HDMi, you appear not to be using this setup ??

Maybe you should start YOUR OWN thread where other users using the VGA66 will see your post ???
Retired disgracefully.....
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Re: Apps known to support dual display

Fri Jan 08, 2016 9:24 am

fruitoftheloom wrote:This thread was in reference to using the Official Touch Display with HDMi, you appear not to be using this setup ??

Maybe you should start YOUR OWN thread where other users using the VGA66 will see your post ???
The dual display issue is actually the same for the VGA666 adapter as the Official Foundation Display. For either of these choices, only one display has a frame buffer device and so only one display can show the X11 desktop. Again for either, you can choose using config.txt which display gets the frame buffer device. The display without the frame buffer device can be used by any software that uses the DispmanX interface of the Raspberry Pi.

So why do we need separate threads to solve the same issues?

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Re: Apps known to support dual display

Fri Jan 08, 2016 9:38 am

For my particular project I don't want or need X11. I'd like to use Kivy with the 7" display for the GUI, and hdmi to display a jpeg. So if I am understanding it correctly the 7" display doesn't use a framebuffer, so I should be able to use fbi to display the jpg? Just researching at the moment until I can get access to the TV this weekend.....
Texy
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

fruitoftheloom
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Re: Apps known to support dual display

Fri Jan 08, 2016 9:42 am

AndyD wrote:
fruitoftheloom wrote:This thread was in reference to using the Official Touch Display with HDMi, you appear not to be using this setup ??

Maybe you should start YOUR OWN thread where other users using the VGA66 will see your post ???
The dual display issue is actually the same for the VGA666 adapter as the Official Foundation Display. For either of these choices, only one display has a frame buffer device and so only one display can show the X11 desktop. Again for either, you can choose using config.txt which display gets the frame buffer device. The display without the frame buffer device can be used by any software that uses the DispmanX interface of the Raspberry Pi.

So why do we need separate threads to solve the same issues?
Because the OP was asking a specific question relating to HIS use,
not asking about someone elses use of VGA66 dual-display :shock:

Is it polite to hijack threads :?:
Retired disgracefully.....
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texy
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Re: Apps known to support dual display

Fri Jan 08, 2016 9:48 am

fruitoftheloom wrote:
AndyD wrote:
fruitoftheloom wrote:This thread was in reference to using the Official Touch Display with HDMi, you appear not to be using this setup ??

Maybe you should start YOUR OWN thread where other users using the VGA66 will see your post ???
The dual display issue is actually the same for the VGA666 adapter as the Official Foundation Display. For either of these choices, only one display has a frame buffer device and so only one display can show the X11 desktop. Again for either, you can choose using config.txt which display gets the frame buffer device. The display without the frame buffer device can be used by any software that uses the DispmanX interface of the Raspberry Pi.

So why do we need separate threads to solve the same issues?
Because the OP was asking a specific question relating to HIS use,
not asking about someone elses use of VGA66 dual-display :shock:

Is it polite to hijack threads :?:
Pot-kettle-black :roll:
You've added nothing to the thread on the subject matter.
Texy
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

Wietse
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Re: Apps known to support dual display

Fri Jan 08, 2016 12:56 pm

Sorry texy, I wasn't trying to hijack the thread. AndyD, thank you for pointing out the DispmanX necessity. Just to finish the question of pobalopalous:
I'm particularly interested in a browser that can be launched fullscreen on the HDMI display.

Is there a web browser that is able to be launched from one screen (either a touch display or vga 666) to be displayed on the other i.e. HDMI screen? I am guessing that there currently isn't any right?

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topguy
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Re: Apps known to support dual display

Fri Jan 08, 2016 6:32 pm

One can use Qt5 and WebKit to create a browser and run it with the EGLFS rendrer. I just tested that the other day, the trick is still to use VC_DISPLAY to redirect it to correct display.

Unfortunatly the Qt5 version in Raspbian is not built correctly for EGLFS so you have to build it yourself or use someone elses packages.

Tryph
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Re: Apps known to support dual display

Thu Jan 14, 2016 10:14 pm

ghans wrote:Exactly.

So far i know this limits users to Kivy , Kodi and omxplayer. There was a new enviroment variable for other dispmanx apps too - i just can't find the thread now ...

ghans
Hi,

how exactly do you run Kodi on the HDMI when using official LCD display by default? i can't find any way to do it.

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