jernej

That is default fallback resolution when kernel can't read resolution info from display (on all platforms and architectures). There can be multiple reasons, like cable, monitor, some kernel/driver issue...

Your understanding is incorrect: 1. VDPAU was used only with vendor kernel, which is obsolete for a long time. Armbian uses only mainline kernel. 2. No need to worry due to 1) 3. GPU doesn't do anything for video decoding. That's desktop PC concept. Embedded SoCs have dedicated VPUs (video processing unit). But it's true that ffmpeg need patching. More specifically, it needs v4l2 request api support. 4. That's not necessary if ffmpeg libraries are patched and installed system wide. Last but not least, v4l2 request video decoding support is tested only in Kodi GBM mode. This means that it must be started from console, when no desktop environment is running. Maybe wayland mode would work, but I don't know. Certainly it won't work under X11. You have to use software decoding there.