About a week ago, OnePlus broke the ability to edit slow-motion videos in its Gallery. The latest app update, which is now rolling out on the Play Store, fixes that. It also adds 4K 60fps video editing, which was so far impossible to do in the native app. There's also casting support, supposedly.
Many recent OnePlus phones can record video in 4K 60fps (instead of the default 4K 30fps mode), but until now, those videos weren't editable by the devices' built-in Gallery app. If you tried to edit, a pop-up warned you that the option wasn't supported. This is now working with v3.12.28 of the Gallery app. You can trim the video, apply a color filter, and overlay music instead of the recorded audio.
Left: Pop-up in older versions. Middle: Editing in v3.12.28. Right: 4K 60fps video file details.
v3.12.28 also fixes the missing slow-motion video editing option, which was disabled with v3.12.19 of the app.
Left: v3.12.19. Middle & Right: v3.12.28.
This version also supposedly adds casting ability, as discovered by XDA Developers recently, but nothing I tried made the Chromecast button show up. It could be that the change is triggered server-side or doesn't work on my OnePlus 7 Pro, but the changelog mentions "projecting to OnePlus TV" so it might also be that casting is limited to OPTV units. I have an Nvidia Shield and a Lenovo Smart Display, both of which are cast targets. The limitation to OPTV, if it's true, would be unnecessary and annoying.
1. Fix issues including sharing photos from gallery, red color, and photo missing
2. Fix slow-motion video editor
3. Add photo projecting to OnePlus TV
4. Add 4K60fps video editing