Trying UVD causes my system crash and hang on my RV730. Unfortunately I was not able to get any backtrace logs after rebooting cause it is not saves.

I tried:

mpv -vo vdpau -hwdec=vdpau
mpt -vo vaapi -hwdec=vaapi

it starts to play for a second but then display becomes black and only hardware reset can reanimate my system.

Kubuntu 18.04
Linux: 4.15.0-12-generic x86_64
mesa-vdpau-drivers: 18.0.0~rc4-1ubuntu3
libva2: 2.1.0-1

$ lspci | grep -i vga
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV730 XT [Radeon HD 4670]

$ glxinfo | grep -i version
server glx version string: 1.4
client glx version string: 1.4
GLX version: 1.4
    Version: 18.0.0
    Max core profile version: 3.3
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.0
OpenGL core profile version string: 3.3 (Core Profile) Mesa 18.0.0-rc4
OpenGL core profile shading language version string: 3.30
OpenGL version string: 3.0 Mesa 18.0.0-rc4
OpenGL shading language version string: 1.30
OpenGL ES profile version string: OpenGL ES 3.0 Mesa 18.0.0-rc4
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.00