On 9/12/19, Michael Koch <[email protected]> wrote: > Paul, > >> >>>> Make this correction: >>>> >>>> new_fov = 180 * tan(fov/4) >>>> >>>> where fov the the field of view you get from the command line, and >>>> fov_new is the value that you use for the filter. >>>> You must exclude values too close to 360°, because 360° stereographic >>>> projection is impossible. >>>> >>> P.S. of course fov must be converted to radians before using tan(): >>> >>> new_fov = 180 * tan(fov * pi / 720) >> Thanks, that cleared some stuff. >> Should be fixed. > > Converting from equirectangular to stereographic is working fine now. > Field of view is correct. > But in the other direction from stereographic to equirectangular the > output is wrong. > The output doesn't contain any no-data areas. I mean those areas that > aren't visible in the stereographic input. These areas should be filled > with black (or better a user-defined color).
That is not doable by design. > Also, the default output size should be width/height=2, but it is quadratic. output size for what? > I tested with these command lines: > > ffmpeg -i equirectangular_test.png -lavfi > "v360=input=e:output=sg:h_fov=300:v_fov=300" -y sg.png > ffmpeg -i sg.png -lavfi "v360=input=sg:output=e:h_fov=300:v_fov=300" -y > e.png > > Michael > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
