Qt on IPU graphics plane for iMX6q

[andreatessadri]

Hi,

   I am using an iMX6q processor with 2 IPUs, both able to handle 2 different flows video+graphics for each IPU.

Since I have 2 cameras, I thought to use /dev/fb0 (BG) for one and /dev/fb1 (FG) for another on the same IPU in order to have 2 live images rendered on the screen

Looking at DMA channels I have:

- channel 23 going to display (background) /dev/fb0

- channel 27 going to display (foregraound) /dev/fb1

The 2 flows coming from the cameras are:

- channel 11 going to IC and then to channel 23

- channel 12 going to IC and then to channel 27

By the way, I would like also to put some graphics elements made with Qt 5.4.0

Since flows coming from the camera can also accept graphics planes (channels 14 and 15) I am wondering how to make Qt (or eglfs driver or ... maybe ... linuxfb driver) able to render graphics on that planes.

Thank you in advance

   Andrew

   Italy

[jamesbone]

For getting two cameras you would need to use Rogerio's patch:

i.mx6：two camera work at the same time

[athomas]

I have had success using X11 with Qt and hardware acceleration, but I have not gotten eglfs working. Linux FB is a software solution and does not use all of the hardware capabilities available. I have just recently gone back to trying to get the eglfs working though. Let me know if you had any success. Noticing that applications are crashing when I run with eglfs.

I was able to get Qt to fix a EGL configuration mismatch bug that is going to be rolled into 5.5, but in the mean time you can replace the hard coding patch for the EGL configuration with the patch linked at:

[QTBUG-44290] IMX6 - Failure to match EGLConfig and X Visual buffer depth crashes app - Qt Bug Track...