[yocto] Screenshot tool

[Evan O'Loughlin]

Hi Herman,

Thanks for providing links to the screenshooter source.

Based on your code I've tried implementing a similar method within our application but I still get a blank (black) image.

It's possible that under the hood the 'grabWindow' method is just saving the framebuffer.


Regards,
Evan

-----Original Message-----
From: Herman van Hazendonk [mailto:me at herrie.org] 
Sent: 16 April 2019 10:19
To: Evan O'Loughlin <evan.oloughlin at vitalograph.ie>
Cc: yocto at yoctoproject.org
Subject: Re: [yocto] Screenshot tool

Hi Evan,

We don't currently have a 4.9 kernel running for our project since we're working mainly with mobile devices which are stuck on 3.4 and 3.18 kernels for now, however we do have small screenshot utility which we have as a plugin to our compositor which we have been using since early
Qt5 releases and we're currently on Qt 5.11/5.12.

Might be worth to give a go at your end:

https://github.com/webOS-ports/luna-next/blob/f5fc4c8af0d0c6f74f57d3963eb570966bc8fa55/plugins/compositor/screenshooter.cpp

And the header file at:

https://github.com/webOS-ports/luna-next/blob/f5fc4c8af0d0c6f74f57d3963eb570966bc8fa55/plugins/compositor/screenshooter.h

Hope this helps.

Best regards,
Herman

On 2019-04-16 09:15, Evan O'Loughlin wrote:
> Hi,
> 
> I’m currently using yocto to build a custom OS based on Linux 4.9 for 
> our hardware:
> Build Configuration:
> BB_VERSION        = "1.32.0"
> BUILD_SYS         = "x86_64-linux"
> NATIVELSBSTRING   = "Ubuntu-16.04"
> TARGET_SYS        = "arm-linux-gnueabi"
> MACHINE           = "CUSTOM_MACHINE_NAME"
> DISTRO            = "arago"
> DISTRO_VERSION    = "2017.12"
> TUNE_FEATURES     = "arm armv7a vfp thumb neon       
> callconvention-hard"
> TARGET_FPU        = "hard"
> meta-processor-sdk = "HEAD:92db4d8023d88ab59fab2953e7447ec0bd5a6db1"
> meta-ros          = "HEAD:e2566402ab108a19634354a934788109422cf409"
> meta-arago-distro
> meta-arago-extras = "HEAD:5b2a44b0c4d989133bc13d59398fd10375d351bb"
> meta-browser      = "HEAD:26d50665e2f7223c5f4ad7481a8d2431e7cb55fb"
> meta-openamp      = "HEAD:8a214032bfb7e8124bc1485c70c69f7d60abb819"
> meta-qt5          = "HEAD:2c9f0e4eb0e9097f6f872ec1e1d81768a8ab5f1b"
> meta-networking
> meta-ruby
> meta-python
> meta-oe
> meta-gnome
> meta-multimedia   = "HEAD:b40116cf457b88a2db14b86fda9627fb34d56ae6"
> meta-ti           = "HEAD:3dc08477529b31ce887bb22a08201a843ded48f0"
> meta-linaro-toolchain
> meta-optee        = "HEAD:d73e794c7e7ebb1cc5bf495a52a72b26fb118250"
> meta              = "HEAD:39fd8c129e2bff7f2f1649b7f6e036ccc50fd5d8"
> meta-custom  = "########################################"
> meta-printing     = "morty:72811bc3755d1a943fa2a2e79601781b44a77420"
> 
> 
> We run a Qt5 application using EGLFS but can no longer capture 
> screenshots.
> In a previous yocto build based on Linux 3.x we were able to use a 
> screenshot tool which effectively just read /dev/fb0 to a file.
> 
> I believe this was a change to how the underlying drivers interact 
> with the GPU/Screen - I've started reading up on KMS/DRM.
> 
> 
> Does anyone know is there a utility/tool which I could use to capture 
> the Qt5 application as its drawn on screen?
> 
> 
> Regards,
> Evan