The problem:
You've installed a video conversion app on Windows 10, but it seems to be missing the option to encode/convert/output to H.265 HEVC.
The solution:
1. Download the latest MS HEVC Video Extension AppX package from Free-Codecs.com .
Make sure to select the correct architecture for your system (x86/x64) - Green button for x86, Red button for x64. The ones on top should be the latest ones.
These AppX packages are digitally signed by Microsoft and are safe to download & install.
It's also available directly from the MS Store , but it seems to be a paid app.
2. Install the package by double-clicking on it. If Smart Screen comes up, click Run.
3. Open the Microsoft Store app > click on the Library icon (lower left) > Click on "Get Updates" (upper right).
Let it update all your UWP apps to the latest version. Most likely it will also update
the HEVC extension package you just installed. Close the Store when done.
4. Important! Open an HEVC video file with the built-in "Movies & TV" app. Wait until you see the video playing, and then close it. I'm not sure what it does, but it looks like it "enables" the HEVC codec (it seems to require internet access).
* If you have a 3rd party firewall running, allow "Movies & TV" internet access until you see the video playing.
5. Now if you open a video conversion app, for example, Movavi Video Converter, you'll get an additional option - to output the video to H.265 (HEVC).
* EDIT: Confirmed working with Apple iPhone 13 Pro HEVC videos.
