IMX415 + NPU demo on ROCK 5B

Can you explain what this is for?

Not sure i understand the question, i will try to answer and be brief.

Those are deb built by Rockchip members to get most of the board working features, like HW video acceleration, 3D, 2D, and encoder, and decoder working as expected on their BSP/SDK.

If you don’t want to spend hours, weeks, or months figuring out how to build it yourselves you just install the required deb to make gstreamer work. In order not to have dependencies errors like the above, you start with a clean image and then install what you need.

You can use a ready-to-use image if you don’t want those hassles. At some point, you will need to get your hands dirty to fix things that broke when you update to the latest kernel version.