independent rotation of each half of dual fisheye Gear360 video

Question

The Samsung Gear360 2017 records dual-fisheye video. ie. two side-by-side circular images in a black square, one from each lens. mediainfo reports:

General
[...]
Format           : MPEG-4
Format profile   : Base Media / Version 2
Codec ID         : mp42 (mp42/isom/hvc1)
[...]
Video
[...]
Format           : HEVC
Format/Info      : High Efficiency Video Coding
Format profile   : Main@L5.1@Main
Codec ID         : hvc1
Codec ID/Info    : High Efficiency Video Coding

I use the camera as a bicycle dashcam. As I am using linux and don't usually care enough to convert for proper viewing, I just view the raw files off the sdcard.

This is fine if the camera is placed upright. The left and right circles are oriented as:

       top         |         top
left        right  |  left        right
     bottom        |       bottom

However, if the camera is placed on its side when recording, which would be more convenient for mounting on my bike, it does not detect or compensate for the orientation and the layout becomes:

       left        |       right
bottom      top    |  top        bottom
      right        |       left

Is there a fast, simple, ideally lossless, way to independently rotate the two halves of the video, the left half by 90 degrees anti-clockwise and the right half by 90 degrees clockwise?

Perhaps ffmpeg or mpv, etc, can do this?

Answer 1

Here is the best reference on using FFMPEG. You will see how to convert dual fisheye images to equirectangular and align image to desired orientation. The alternative is to use Mistika Boutique by SGO under Education license for free. The latter needs moderately powerful PC.

Michael Koch, Astroelectronic FFMPEG Notes 2023