[FFmpeg-user] V360 filter

[Paul B Mahol]

On 9/10/19, Michael Koch <astroelectronic at t-online.de> wrote:
> Paul,
>
>> Stereographic projection aka little planet added as both input and output.
>> Single fisheye is little different.
>
> v_fov is limited to 90°, that's not enough for little planet.

I increased it.

>
>>
>>> -- I think the d_flip parameter needs some more documentation. What's an
>>> "in-depth" flip?
>> It swaps back with front.
>
> Please add it to the documentation, "in-depth" flip isn't self-explaining.
>
>
> I have a workaround for converting an equirectangular video to a little
> planet video, but I use a fisheye projection (vertical coordinate in
> equirectangular image is proportional to distance from image center in
> little planet image):
>
> set "IN=test3.mp4"          :: Equirectangular input video
> set "H=960"               :: Height of input video (width = 2 * height)
> set "S=1080"                :: Size of quadratic little planet output video
> set "OUT=out.mp4"           :: Output video
>
> rem Create the xmap file
> ffmpeg -f lavfi -i nullsrc=size=%S%x%S% -vf format=pix_fmts=gray16le,^
> geq='%H%*(0.9999+atan2(Y-%S%/2,X-%S%/2)/PI)' -frames 1 -y xmap.pgm
>
> rem Create the ymap file
> ffmpeg -f lavfi -i nullsrc=size=%S%x%S% -vf format=pix_fmts=gray16le,^
> geq='%H%*(1-hypot((2*X/%S%)-1,(2*Y/%S%)-1))' -frames 1 -y ymap.pgm
>
> rem Apply the remap filter to the video
> ffmpeg -i %IN% -i xmap.pgm -i ymap.pgm -lavfi
> "format=pix_fmts=rgb24,remap" -y %OUT%
>

You sure that is little planet projection?

It is not, it is 360 deg fisheye.

>
> Michael
>
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email
> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".