IIRC RPi 4/5 only support Vulkan under Wayland, and we do not run Kodi under Wayland because Wayland does not support refresh rate changing for optimal media playback. So yes FFMpeg added some support for DV but the devil is in the details and this is not a usable solution for our use-case. I'd also argue that using shaders is not "true" DV support; it's simply a way to get DV encumbered media to display with an acceptable (but not exact) on-screen appearance. True support requires knowledge of the proprietary stuff or a clean-room implementation. The former won't happen because it torpedo's Dolby's commercial model and the latter is rather unlikely since it will require a massive effort and the Linux community generally prefers to make a minimum acceptable effort when the target "standard" is vendor proprietary crap. I'll update/reword the wiki article a little to prevent further 2+2=5 conclusions.
Okay, but nobody says it has to be a 'true' implementation of DV, if there is a good enough one that does Profile 5 conversion to HDR/PQ or SDR and reads side data, it is functional and compatible enough, it is interesting at least to discuss. We're not expecting a 'clean implementation' anywhere near. If the linux community has put an effort in developing this library, obviously they don't consider DV 'propietry crap'. We're talking that most HDR content is in DV, and there are platforms and displays that don't support (or license) it, be TVs (old and new), the most popular RPI or even Windows (Does Windows include free/licensed DV software decoding yet?). If LE is open source, based on ffmpeg and it might include this powerful library (not just for DV decoding, but GPU offloading, jinc upscaling), I think it is worth mentioning. I don't know how LE plays HDR, I read it does by V4L, DRM framebuffer, or KMS on low level programming (I'm not an expert and do not know exactly) and a tight ffmpeg integration.
If you say RPI4/5 only support Vulkan under Wayland, okay I get it, although it doesn't mention this on building documentation: it only requires support for either opengl, vulkan or d3d11. I'm not sure DV decoding requires Vulkan.
But talking about Wayland: RPi has got full working support of it on their official desktop distro. RPI has a Vulkan and OpenGL driver GPU. Open source Mpv player, manages HDR and SDR in Windows and Linux. Is there any talks to move from low level DRM processing to a standard Wayland protocol and display server/compositor without requiring a full desktop environment/window manager?
You say "we do not run Kodi under Wayland because Wayland does not support refresh rate changing for optimal media playback", does it mean it is feasible? How many real content has refresh rate changing? I think some cell phones record video in minimal variable framerate, I don't know if this apply.
Does Wayland expect support for HDR soon to begin with? (passing HDR metadata)
I hope my rant is interesting for someone. It's meant for learning and discussing direction. Thanks for the support.
