HDMI output linearity

pierluigi_p — Fri, 19 Nov 2021 23:15:29 GMT

Dear NXP support,

one of our customers is using a SoM based on iMX8MQ with kernel based on branch imx_5.4.24_2.1.0 and Xwayland.

He displayed a linear grayscale gradient (graygradient.png) via HDMI.

Then he used a MAGEWELL "USB Capture HDMI Gen 2" to capture a frame (grayframe.png) from HDMI.

From a comparative analsys of the 2 images (graycompare.png) it turned out a kind of non linearity in the HDMI output.

Is there any know explanation for this behavior?

Thanks

Pier

Re: HDMI output linearity

Zhiming_Liu — Tue, 23 Nov 2021 02:45:38 GMT

I can't find similiar issue in internal jira.

Can customer try the newest bsp?If this issue exist in newest bsp, i can report it to internal.