~ $ mpv -vo=opengl-hq -hwdec=vaapi test.mkv 
Playing: test.mkv
Can not open external file test.txt.
[stream] Video (+) --vid=1 (h264)
[stream] Audio (+) --aid=1 (*) (ac3)
libva info: VA-API version 0.35.1
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib64/va/drivers/radeonsi_drv_video.so
libva info: va_openDriver() returns -1
[vaapi] vaInitialize(): unknown libva error
[vo/opengl-hq] Couldn't load hwdec driver 'vaapi'
VO does not support requested hardware decoder.
Using software decoding.
AO: [pulse] 48000Hz stereo 2ch float
VO: [opengl-hq] 1280x720 => 1280x720 yuv420p
AV: 00:00:10 / 00:41:37 (0%) A-V: 0.000





~ $ vlc test.mkv 
VLC media player 2.1.5 Rincewind (revision 2.1.4-49-gdab6cb5)
[0xd561f8] main libvlc: Esecuzione di vlc con l'interfaccia predefinita. Usa 'cvlc' per utilizzare vlc senza interfaccia.
[0xe37918] qt4 interface error: Unable to load extensions module
[0x7f6bc109b9e8] main demux error: option sub-original-fps does not exist
[0x7f6bb0001208] main input error: no suitable demux module for `file/subtitle:///home/niko//test.txt'
No accelerated IMDCT transform found
libva info: VA-API version 0.35.1
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib64/va/drivers/radeonsi_drv_video.so
libva info: va_openDriver() returns -1
[0x7f6b9c000db8] vaapi generic error: Failed to initialize the VAAPI device
libva info: VA-API version 0.35.1
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib64/va/drivers/radeonsi_drv_video.so
libva info: va_openDriver() returns -1
[0x7f6b9c000db8] vaapi generic error: Failed to initialize the VAAPI device
[0x7f6b8c001248] main vout display error: Failed to resize display