vo_dmabuf_wayland: No color correction with HDR content

[rmader]

So far vo_dmabuf_wayland seems to ignore the HDR metadata, forwarding content to the compositor unconditionally. This is problematic as Wayland compositor right now assume BT709 / sRGB content and there's no way to tell them otherwise. The later will change once the color management protocol lands/gets adopted.

Thus vo_dmabuf_wayland should be able to trigger color space conversion from upstream elements, like it already does for pixel formats etc., and use it for any non-BT709 content. Once the color management protocols lands it will be possible to properly negotiate supported HDR modes.

How to test:

• play BT2020 content, such as Camp by Sony), on a Wayland compositor that supports P010

Expected result

• colors should look sharp

Observed result:

• colors look washed out, not as sharp as when using other backends

[Dudemanguy]

The amount of colorspace-related code in vo_dmabuf_wayland is exactly zero. I'll take a peek later and see what existing things we already have for this.

[philipl]

If you are running on Intel hardware, you can use the tonemap_vaapi filter to do this. I have a conceptual TODO to hook this up to as an automatic filter if we can detect that it's needed. I don't know if AMD drivers support it - their approach to vaapi is very bare-bones so I'd be surprised if they do.

[archerallstars]

I try the tonemap_vaapi on Intel iGPU, UHD Graphics 620 (KBL GT2), but the result looks a lot darker than it should've been (I know because I also view the same movie on Prime Video - John Wick 4). Changing the format or the transfer value as specified on https://ffmpeg.org/ffmpeg-filters.html#tonemap_005fvaapi doesn't help.

And I don't think tonemap_vaapi is supported on AMD yet, see: Mesa issue #3865.

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openSUSE Tumbleweed
mpv 0.37
ffmpeg 6.1.1
intel-media-driver 24.1.3

[Dudemanguy]

With #15048, this works now on mutter 47. For any other compositor, they will need to implement xx-color-management-v4 and the correct format for support to work. e.g. kwin works with this MR.