Screenshots using the "Screenshot Output" hotkey only output SDR, even when recording in HDR

Operating System Info

Windows 11

Other OS

No response

OBS Studio Version

32.0.4

OBS Studio Version (Other)

No response

OBS Studio Log URL

https://obsproject.com/logs/QaUXz8goUPUj1dVB

OBS Studio Crash Log URL

No response

Expected Behavior

When recording native HDR content in HDR (i.e. not tonemapping to SDR at any point whatsoever), screenshots should be delivered in native HDR regardless of which screenshot option is used (between "Screenshot Output", "Screenshot Source", and "Screenshot Preview").

Current Behavior

Screenshots taken with the "Screenshot Output" option are delivered in 8-bit SDR PNG, even if the content is a native HDR game capture, recorded to an HDR output.

However, screenshots of the same HDR game capture taken via "Screenshot Source" or "Screenshot Preview" are properly delivered in 10-bit HDR JXR.

Steps to Reproduce

0. Own an HDR display
1. Set up HDR recording output (Set color format to P010, color space to Rec. 2100 (PQ), etc, HEVC profile to main10)
2. Add new game capture source and set the color space to Rec 2100 (PQ)

• 2.5. Make a test recording of an HDR game to verify HDR game recording works

3. Configure the "Screenshot Output" hotkey
4. Take a screenshot using your newly configured hotkey
5. This should result in an 8-bit SDR PNG screenshot, which you can verify with a tool such as MediaInfo or simply by comparing with JXR screenshots taken with "Screenshot Source" or "Screenshot Preview"

Anything else we should know?

This bug notably impacts Elgato's OBS Studio Stream Deck plugin, which features a native screenshot command that happens to use "Screenshot Output" rather than "Screenshot Preview" or "Screenshot Source". Any similar third-party hardware and software integrations may also run into this issue.

Also, I have elected not to include example screenshots in this issue due to GitHub's apparent lack of support for HDR images. Should example image files be requested, I can post some, however GitHub does not accept JXR images and does not render my converted HDR PNGs properly.

Start by tracing OBS Studio's Screenshot Output hotkey path and comparing it with the Screenshot Source and Screenshot Preview paths described in the issue. Reproduce with Windows 11, P010, Rec. 2100 (PQ), and HEVC main10, then verify that Screenshot Output produces native HDR JXR output rather than an 8-bit SDR PNG.