I'm working on a project where I want to replicate the function of horizon levelling presented in the GoPro Player. I have the .360 video files captured with a GoPro MAX. From this I can extract telemetry data (acceleration, gyro, gravity vector) and the 360 degree video in equirectangular form as .mp4 file. I had a bit of search online and most people say it's done by calibrating the gravity vector with gyro data but I have no clue how that's gonna work. Does anyone know how this works or is there any open source code for similar purposes? Thanks a lot 
