vainfo produced no standard output, but gave (in standard error) a very similar error message to the one I reported when attempting mpv on an mp4 file:
wl_drm@7: error 0: authenticate failed
VA error: wayland: Wayland roundtrip error: Protocol error (errno 71)
libva info: VA-API version 1.10.0
libva error: vaGetDriverNameByIndex() failed with invalid VADisplay, driver_name = (null)
vaInitialize failed with error code 3 (invalid VADisplay),exit
vainfo produced no standard output, but gave (in standard error) a very similar error message to the one I reported when attempting mpv on an mp4 file:
wl_drm@7: error 0: authenticate failed ByIndex( ) failed with invalid VADisplay, driver_name = (null)
VA error: wayland: Wayland roundtrip error: Protocol error (errno 71)
libva info: VA-API version 1.10.0
libva error: vaGetDriverName
vaInitialize failed with error code 3 (invalid VADisplay),exit