On Sun, 11 Jul 2021, Rhialto wrote:
If I play a much "harder" video, say H.265 at 1920x1080, the default
output from mpv gets way behind and starts to drop lots of frames.
The default output is "sdl", which I think uses MesaLib/GL. Which is
claimed to be accellerated: (output from glxinfo)
Extended renderer info (GLX_MESA_query_renderer):
Vendor: X.Org (0x1002)
Device: AMD CEDAR (DRM 2.43.0 / 9.2, LLVM 7.0.0) (0x68f9)
Version: 18.3.4
Accelerated: yes
Video memory: 1024MB
Unified memory: no
Preferred profile: core (0x1)
Max core profile version: 3.3
Max compat profile version: 3.1
Max GLES1 profile version: 1.1
OpenGL renderer string: AMD CEDAR (DRM 2.43.0 / 9.2, LLVM 7.0.0)
OpenGL core profile version string: 3.3 (Core Profile) Mesa 18.3.4
OpenGL core profile shading language version string: 3.30
If I increase the cpu frequency this improves and gets ok.
(--vo=gpu, and --vo=drm from wscons behave the same)
How can this be? If it's GPU-accellerated, this should be independent of
the CPU frequency, I would think?
GPU-acceleration does not necessarily imply HW-assisted video decoding.
This latter depends heavily on the decoding capabilities of one's CPU
and the video being played. Some CPUs don't do H.265. Using the `I'
command in mpv will tell you if decoding is being done by the HW.
-RVP