Pixel values of HDMI output

[bruno.kempf]

Hi everybody,

we have problems getting true pixel values when we output video/images on the HDMI port of the Jetson TX2.

We display a reference image on the Jetson TX2 using the default image viewer in full screen mode. We capture the output on HDMI port using a Magewell USB frame grabber (supports capturing of true pixel values). When comparing the pixel values, we get differences between the reference image and the image captured with the frame grabber.

Can you explain why there is a difference between the reference image and the HDMI output?

Best regards
Bruno

[WayneWWW]

Sounds duplicated with this issue. This is due to some conversion in our display pipeline. Pleas use the workaround described in this post.

Full range RGB strange behavior on Nvidia Jetson AGX Xavier Developer Kit

I am using a Nvidia Jetson AGX Xavier Developer Kit with Jetpack 4.5.1 (L4T 32.5.1) and I intend to transmit full range RGB output video over HDMI. I intend to do a special encoding at the bit level, hence I need to keep the video untouched – “bit perfect”. I have set the color space to “RGB” and the color range to “Full” in the xorg.conf. However, I cannot transmit the video without some errors in the RGB values. I have been doing some tests with the following test pattern: [testColor] Note…

[bruno.kempf]

Hi WayneWWW,

the post you referenced was helpful for digging a little bit deeper into the issue, but I still can’t grasp a solution for our problem. The switches that fixed the issue for @cdsousa don’t do the trick. In our case it actually gets even worse.

But the work on this issue has been postponed by my superiors. I would like to come back to my post as soon as I continue the work and tested some approaches I have in mind.

Thank you so far for your quick support!

Best regards
Bruno