Generic: switch to OpenGL

[smp79]

OpenGL has several advantages over current OpenGL ES Generic images:

1. HQ upscaler improvements
2. Dithering support
3. Future Retroplayer OpenGL shader support
4. Colour management support

HDR passthrough would be functional after xbmc/xbmc#26406 is merged.

[antonlacon]

LE13 is Soon(TM), so I believe this needs to be a new device unless the intent is to wait for LE14. If others feel differently, this isn't a strong objection.

Would you see if replacing your Kodi package.mk commit with antonlacon@92f136f works for you? It's a clean up to get x11/wayland/gbm options set in the same part of package.mk. I've been using it for RPi5 builds.

[smp79]

Would you see if replacing your Kodi package.mk commit with antonlacon@92f136f works for you?

👍

LE13 is Soon(TM), so I believe this needs to be a new device unless the intent is to wait for LE14.

It could wait until LE14 I suppose. Not sure if adding it as a new device would be useful to anybody.

[CvH]

Not sure if adding it as a new device would be useful to anybody.

If I understand it right it supersedes gles and just adds features and not removes anything.
So it should replace it in my opinion.

It could wait until LE14 I suppose.

The main problem with that kind of changes are that problems can lurk around dark corners. So a rather big testing phase would not hurt, on the other hand its not new technology and it is widely used so likewise (famous last words) not too much trouble should appear.

[HiassofT]

Just for the kicks I gave this a quick try on RPi (and switched RPi to opengl as well).

First the positive stuff: kodi came up fine on RPi5.

But: as RPi5 only supports OpenGL 3.1 and 1.4 shaders kodi wasn't overly happy as it wants 3.2 (plus a lot of it's shaders are 1.5).

Here's the kodi log from RPi5: https://paste.libreelec.tv/composed-ox.log

Also the quite important direct-to-plane rendering is missing with the GL renderer and videos were software decoded (which is not great for 4k60)

Next test on RPi3: Although kodi GUI came up it was quite unhappy with it's OpenGL 2.1 version (and shaders are also only level 1.2) and the GUI was quite broken - practically unusable due to lots of missing stuff, eg highlighting the currently selected element:

here:s the log from RPi3: https://paste.libreelec.tv/premium-condor.log

[smp79]

Tried it on a rather old AMD Oland GPU - it runs nicely

[antonlacon]

But: as RPi5 only supports OpenGL 3.1 and 1.4 shaders kodi wasn't overly happy as it wants 3.2 (plus a lot of it's shaders are 1.5).

I tried zink on RPI5 to see if it would be better. It's not. Kodi failed to launch (unable to init gbm). Additionally, zink was only providing OpenGL 2.1 and GLSL 1.2:

LibreELEC:~ # MESA_LOADER_DRIVER_OVERRIDE="zink" ./eglinfo  | grep OpenGL
EGL client APIs: OpenGL
OpenGL compatibility profile vendor: Mesa
OpenGL compatibility profile renderer: zink Vulkan 1.3(V3D 7.1.7.0 (MESA_V3DV))
OpenGL compatibility profile version: 2.1 Mesa 24.3.4
OpenGL compatibility profile shading language version: 1.20
OpenGL compatibility profile extensions:

Kodi log: https://paste.libreelec.tv/smashing-emu.log

[smp79]

Can anyone test if this is usable on nvidia? Extra changes to build it with nvidia driver - smp79@cfb5dbe
Looks like it would require some serious hackery to run Kodi on nvidia GBM.

[KOPRajs]

I don't have Nvidia, but I'm going to test this in long-term on my family HTPC along with the upcoming video shader support. I've backported it to my build based on stable LE 12.0.2 and Kodi 21.2 (including the HDR support).

The build is here, if anyone wants to try it:
https://github.com/KOPRajs/LibreELEC.tv/tree/retroplayer-21.2
http://koprajs.mx-net.cz/retroplayer-21.2/LibreELEC-Generic.x86_64-12.0-devel-20250212160024-0fd26c2.tar
http://koprajs.mx-net.cz/retroplayer-21.2/game.libretro-22.1.1.1.zip
http://koprajs.mx-net.cz/retroplayer-21.2/game.shader.presets-22.0.0.1.zip

It is Generic LE 12.0.2 running GBM/GL with the HDR patch + RetroPlayer devel stuff. You need to manually install the 2 above add-ons from zip to get games running with shaders.