You could try CoreELEC.
Thank you - my HDR videos are perfect with CoreELEC now (see screenshot 1, which was totally ugly with Libreelec)
Some others videos (e.g. .ts files, german satellite tv, 720p) still look very very bad (Screenshot 2). I have a also a kind of ghosting with these videos in dark scenes.
Any ideas how to fix this issue with non HDR files? Isnt this a serious bug?!
Btw: I wonder why Libreelec officially supports Khadas Vim1 with these (known?!) issues.