Quite messy, because it normally would require GTK. I made it to alter it to make the commandline version only if gtk USE flag is not active. Probably best would be to contact author to make needed changes to the build concept of the tool.
Created attachment 6909 [details] Ebuild for xvattr-1.3
Forget to add that some choppy video in NVidia cards might be due to the XV_DOUBLE_BUFFER setting being on. With this it is easy to turn off. Some more description of the tool: It have GTK GUI to alter XV contrast brightness saturation hue etc. Don't know if it's any use to non NVidia cards. So somebody pleass test.
Im a pack-horse.
stanislav, please add an acknowledgement to the ChangeLog -- this bug has been sitting in bugzilla forever, and certainly Sami deserves credit.
Merged with my old ebuild - added gtk USE flag.
Works with my ATI All In Wonder 128Pro and GATOS drivers (not those in Gentoo - these do not work).