HDR content has overexposed trickplay preview

[ToTheXtreme64]

Describe the bug

While playing an HDR movie the trickplay preview image is not rendered correctly and is overexposed

To Reproduce

1. Play HDR movie
2. Hover over playback bar
3. See overexposed image

Expected behavior
The trickplay image should not be way too bright

Screenshots

Desktop (please complete the following information):

• OS: Windows 11
• Version 3.0.0 Pre 13

[iwalton3]

The screenshot you sent suggests the problem is a roughly 2.53× gain on SDR content in the screenshot.

Three questions:

1. Have you adjusted the SDR content lightness setting within Windows?
2. Does the trickplay look fine in jellyfin-web? Jellyfin trickplay doesn't properly tonemap some media like Dolby Vision by default.
3. Does the progress bar also look overexposed in real life? The screenshot suggests the UI controls are also being "overexposed".

This is the specific setting I am curious about, if you have it set to max that could be causing this issue:

You can also try throwing hdr-reference-white=203 into the mpv.conf file in your config folder, which you can access from the Playback tab at the bottom of the page. If that fixes it I'd also like to know.

[ToTheXtreme64]

1. No I have not messed with the SDR content brightness setting, and messing with it doesn't seem to make the trickplay seem any more correct
2. The trickplay looks perfect in the browser
3. The progress bar looks fine to me

If I add in the line you mentioned to my mpv.conf the trickplay looks the same.

If I turn HDR off in the windows settings the trickplay looks correct

Thank you

[iwalton3]

Thanks for the update, that helped settle this.

It's an upstream problem, tonemapping for the video is also being applied to the trickplay thumbnails. The thumbnails from Jellyfin are SDR and are already tonemapped, so the colors get blown out by that.

Relevant also to:

• Thumbfast (they had the reverse issue, HDR overlays broke): Remove tonemapping po5/thumbfast#24 (comment)
• MPV Upstream: Support colorspace tag for OSD, Subtitles and overlay-add mpv-player/mpv#10678

[iwalton3]

mpv-player/mpv#18392

This patch is confirmed to fix it. Will keep an eye out if it lands in a buildable version on Windows especially, the shinchiro release right now is pinned because I was getting a vulkan dll error on it in testing.