As of now, this is the situation with common distros in regard to supporting hardware acceleration:
- Ubuntu: Not by default but possible with ubuntu-restricted-extras and few other packages all in repos and easily done with gui or cli
- Fedora: Not by default but easily possible by installing mesa-freeworld from rpmfusion repo. All steps possible within gui
- Arch and other arch based distros : Not even an issue
- Manjaro: Not by default. Install mesa-git from AUR or manually compile mesa manually or with PKGBUILD from manjaro with necessary changes. Not applicable to intel users and users with nvidia proprietary drivers
Of all the distros commonly used, manjaro has worst support as of now, and it makes it a difficult recommendation to AMD users. A simple way to get a mesa build with hardware decode support with patented software is required, that supports automatic updates and is accessible to average user.
For general idea about what is being referred to, read here