Hey @PaulF - thanks for doing the heavy lifting here! This really helped me get started.   I was trying to wrap my head around cropping the right part of the frame when I stumbled into something that might make the solution to this problem even easier!   I ended up with the following filter string for ffmpeg:   -vf v360=fisheye:output=flat:ih_fov=180:iv_fov=180:order=rpy:roll=165:pitch=60:d_fov=90   let me try and explain what's going on there (at least what I think is happening)   By saying `output=flat` we're asking ffmpeg to go straight to a normal flat/rectilinear projection   The `ih_fov=180:iv_fov=180` tells it the fisheye field of view, but interestingly enough ffmpeg seems to assume the fisheye is facing "forward" (for lack of a better word). This part was important to realise, since these cameras are almost certainly ceiling mounted facing down.   `order:rpy` says apply the camera movements in the order, roll, pitch then yaw. This lets makes it easier to think about the camera movements. Imagine your standing under the camera and looking at your feet. We start with roll, which equates to turning on the spot, positive roll is turning to your right, negative to the left. Then pitch, which lifting your gaze from your feet (pitch=0) to the horizon (pitch=90)   Finally `d_fov` is like zooming in or out.   All of this is kind hurting my brain, but it did let me crop exactly what I wanted from the dewarped image, and I hope it helps someone else!     ... View more