I have a pretty low end machine (AcerC720) and I relied on hardware accelerated video decode for smooth video playback using Arch which worked flawlessly. This is currently a blocker for me switching to solus.
Prerequisites
an intel gpu
intel vaapi driver
# eopkg it libva-intel-driver
mpv and vlc
# eopkg it mpv vlc
Testing
Running these commands
$ vainfo $ mpv --profile=opengl-hq --hwdec=vaapi test.file $ vlc --vout=glx --avcodec-hw=vaapi test.file
This is the test file I used: https://www.dropbox.com/s/zr068zb69lvs9ht/1080i_4ChAud.ts
Output from Arch
Output from Solus
Under solus both mpv and vlc fall back to software decoding even though the output from vainfo suggests that vaapi is correctly configured on the system.
The most helpful output is from mpv which says:
VO does not support requested hardware decoder, or loading it failed.
Further reading
https://wiki.archlinux.org/index.php/Hardware_video_acceleration