[FFmpeg-user] rounding errors in v360 filter

[Michael Koch]

Am 23.02.2020 um 18:20 schrieb Paul B Mahol:
> On 2/23/20, Michael Koch <astroelectronic at t-online.de> wrote:
>> Hi,
>>
>> there seem to be some rounding (or +-1) errors in the v360 filter, when
>> converting from double fisheye to equirectangular. Can be reproduced as
>> follows:
>>
>> ffmpeg -f lavfi -i color=red:size=40x40 -f lavfi -i
>> color=green:size=40x40 -lavfi
>> "[0][1]hstack,v360=input=dfisheye:output=e" -frames 1 -y out.png
>>
> Fixed.

Thank you. For testing I must wait until it becomes available on Zeranoe.
I just found a similar problem in v360 conversion from equirectangular 
to fisheye, but here the problem is only in y axis. The center of the 
fisheye image is half a pixel too low. In x axis it's correctly centered.

ffmpeg -f lavfi -i color=red:size=10x20 -f lavfi -i 
color=green:size=20x20 -f lavfi -i color=red:size=10x20 -lavfi 
"[0][1][2]hstack=inputs=3,format=rgb24,v360=input=e:output=fisheye:d_fov=270" 
-frames 1 -y out.png

Michael