Implement JPGXL or AVIF format options for video snapshots

[Apposite245]

The fewer issues I have to read, the more new features I will have time to implement, so I ask that you please try these things first

• [X] Check out all the menus and keyboard shortcuts. Maybe the feature already exists?
• [X] Try with the newest version from GitHub
• [X] Read the documentation and FAQ, Known issues, Troubleshooting to see if the feature already exists
• [X] See if someone already suggested this under Issues or Discussions

Description

With HDR becoming more and more prevalent due to the increase in support from modern smartphones as well as HDR film and tv releases, having a way to capture accurate stills from HDR content would be greatly appreciated.

It seems that ffmpeg already supports JPGXL using libjxl.

[mifi]

added your suggestion here: #1907