Add full support for Rec. 2100 (PQ)

[shotcut]

You can already do it if your source is HDR and do not need preview. In Export, start with a 10-bit preset, then in the Other tab change/add:

mlt_image_format=yuv420p10
colorspace=2020
color_trc=smpte2084

You also need to avoid certain effects before version 25.12: track compositing/blending, transitions, filters without the #10bit tag. With 25.12 you can use a 10-bit processing mode and do track blending as well as transitions, and there are many more 10-bit safe filters.

With the x265-based HEVC preset, you can add metadata:
x265-params=master-display=G(8500,39850)B(6550,2300)R(35400,14600)WP(15635,16450)L(10000000,50):max-cll=1000,300

You should get the exact values from the source.

For more simplicity and external HLG HDR preview see

Editing HDR Source Clips

Introduction Some users report that their clip looks “washed out” or “pale” in Shotcut compared to media players. This is often because the clip is encoded as High Dynamic Range (HDR). Shotcut has very limited support for editing HDR, and most users do not want to bother with HDR output. So, HDR clips can be converted to SDR that Shotcut can edit. Identifying HDR Clips To identify HDR clips in Shotcut, open the clip and view the Properties panel. In the properties panel, look for the “Color t…

HDR export options are not explicit in the UI until embedded preview works because without that, there will be confusion and bug reports. And I have not been able to figure out how to get embedded HDR preview working with the current software architecture of the app.