Rotate a video taken on an iPhone, and save it as an MP4 I was recording a video on an iPhone and I had it "upside down" by mistake, meaning the camera was in the bottom-right corner rather than the top-left.

When I watch the video on my Mac in Quicktime, the orientation is fine, anyway, but when I watch it in VLC, then it is upside down. I want to fix the orientation because I want to convert the video from MOV to MP4, and this would also make it upside down (because it loses the orientation/rotation metadata that the MOV file contains, to properly orient the video).

How can I properly rotate the video so that it looks correct?

I tried a few methods already, but none worked. For instance, I tried this (Can HandBrake flip/rotate a video?), but that didn't work for me. I also tried this (
video captured from iphone gets rotated when converted to .mp4 using ffmpeg
) but I got a few errors in Terminal when running the commands, like regarding experimental features, etc.
I opened iMovie, and imported the upside down video (which only appears upside down in non-Apple apps, like VLC). Since iMovie is an Apple app, it is able to read the rotation metadata, so it showed the video correctly. I then simply exported the video as an MP4 from iMovie, which resulted in a video with the correct orientation.

No manual rotation was necessary in iMovie since it already was able to read that metadata, as I mentioned.