imx8mm v4l2 capture and display on screen

[greeranjunk]

hello

i am trying to run the mx6_v4l2_capture example. the capture works but the display part does not. it fails on the "FBIOPUT_VSCREENINFO failed 2-[22 : Invalid argument]"
it seems that setting the FB_VSCREENINFO fials.

when i change the code from

var.yres_virtual = 3 * var.yres;

to

var.yres_virtual = var.yres;

the put is successful but the FBIOPAN_DISPLAY  fails.

could someone explain how i need to configure the display or does the IMX8MM not support this sort of display

thanks

Ran

[greeranjunk]

is it possible that the IMX8mm does not support the V4L2 unittest (/unit_tests/V4L )

[greeranjunk]

hi Igor

thanks for the replay. i tried this test but it seems to fail on the FBIOPUT octl. i am using the default (mode =0) with default values and i get

./mx6s_v4l2_capture.out -m 0

---- Running < ./mx6s_v4l2_capture.out > test ----

Found v4l2 capture device /dev/video0.
pixelformat (output by camera): YUYV
WxH@fps = 640x480@30 Image size = 614400
FBIOPUT_VSCREENINFO failed 2-[22 : Invalid argument]

---- Test < ./mx6s_v4l2_capture.out > ended ----

I am running it on an imx8mm evaluation board. could you tell me why i fail to set the FB

thansk

Ran

[greeranjunk]

i forgot to add that i get also

[drm:drm_fb_helper_check_var] fb requested width/height/bpp can't fit in current fb request 800x480-32 (virtual 800x1440) > 800x480-32

in the dmesg. the drm_fb fails and the comment in function where it fails

/*
* Changes struct fb_var_screeninfo are currently not pushed back
* to KMS, hence fail if different settings are requested.
*/

does it mean that i cannot change the screeninfo ? so how can i display the frames

thanks

[igorpadykov]

Hi Ran

i.mx6_v4l2_capture is used for processors with IPU, for i.MX8M Mini one can try i.mx6s_v4l2_capture.c

https://source.codeaurora.org/external/imx/imx-test/tree/test/mxc_v4l2_test/mx6s_v4l2_capture.c?h=im...

Best regards
igor

[greeranjunk]

hi Igor

i by mistake replied to my message and not yours. if you could see my replies please

thanks

Ran