horai wrote: ↑
Sat Apr 14, 2018 2:30 pm
Thank you for suggestion, like you said that is reasonably when having ARM v7, but my application is supposed to work on arm v6 (Pi Zero), we use RPI3 only for compilation and testing and also there is no official image yet, I believe it could be very good in some ways (64 bit support) but I stick with Raspbian so far.
Anyway, the slow video rendering drives me crazy, it could be caused by clutter as clutter seems to be running on top of COGL because of this:
When running my application X11, I experienced huge increase in speed when running video rendering in X11 (in a window) using clutter but switching the video driver from default one to VC4 KMS (I guess it is OpenGL not OpenGL|ES2), that means Gallium on top of VC4 driver in X11. I don't know much about the layers behind but default repository COGL library with X11 support only could be build with GLES2 and OpenGL (GL) support and it could detect drivers internally and utilize the driver whichever is available (that was probably done in my case with X11, when KMS driver was present, it started to use OpenGL instead of GLES2 and the video rendering speed increased dramatically), unfortunately I built COGL with GLES2 support and without GL support (I guess this is the KMS openGL driver) moreover in COGL ./configure there is also some gstreamer support disabled by default.
These are all the reasons I suspect the OpenGL driver to be responsible for the speed increase. I'll enable GLES2 (or maybe disable GLES2 to make sure it is not using GLES2 but GL), GL and gstreamer and give it a try.
Weston (Wayland) is definitely running on Gallium VC4, EGL, at least according to log file so I hope there is no need to touch both.
What I don't fully understand is Eric Anholt statement:
VC4 at the hardware level is a GLES 2.0 renderer. However, along with GLES 2.0, the Mesa driver also exposes OpenGL 2.1, which is mostly correct but with a few caveats.
I don't know if this statement could mean that using OpenGL could speed up video rendering compared to GLES 2.0 if both are GLES2 renderers on hardware level.
Please, if anyone is reading this conversation, I would like to encourage all to comment any wrong statement I have mentioned, I don't find myself any expert in this field and I want to make clear I understand the underlying issues properly in order to optimize video speed in Wayland.
By the way, could anyone also explain me why Wayland support in Raspbian was postponed for indefinite, I read everywhere how better Wayland should be compared to X11, there are multiple videos on Youtube showing benefits of Wayland/Weston fast window rendering compared to poor X11 performance.
It is just because of the fact the whole distribution would require a lot of work to suit and tune all applications to Wayland backend or is Raspbian waiting for for Debian to make Wayland default?