[FFmpeg-user] Does v360 filter support dewarping circular fisheye images?

[Michael Koch]

Am 24.12.2020 um 10:42 schrieb thongtm2:
> I have a fisheye camera (360 degrees in horizontal & 180 degrees in
> vertical). Is it possible to use v360 filter to dewarp circular fisheye
> images to single perspective images (flatten fisheye images)? I've tried
> many options but the results were not as I expected. Below command is one of
> them:
>   ffplay fisheye_video.mp4 -vf
> v360=fisheye:ih_fov=360:iv_fov=180:flat:yaw=120:pitch=0:roll=0

There are several problems in your command line.
1. As Paul has already pointed out, ih_fov and iv_fov must have the same 
value for fisheye input. In your case both must be 180.
2. It also makes sense to specify the output field of view h_fov and 
v_fov and the output size w and h, because the default values aren't 
known (unless you look in the source code).
3. The command line is better readable if you don't omit the names of 
the options. I mean "output=flat". The names can be omitted if the 
options are specified exactly in the correct order. Your command line 
may work as it is, but it would be better if "flat" or "output=flat" is 
the second option.

This should work:
v360=input=fisheye:output=flat:ih_fov=180:iv_fov=180:h_fov=90:v_fov=60:w=900:h=600:pitch=-60

Michael