zoompan 'd' arguments loops video

[igorfil]

I have a short 5-second video at 25 fps (125 frames). I try to apply 'zoompan', but the 'd' argument loops video d times.

For example,

(
    ffmpeg
    .input("3.png", loop=1, t=5)
    .zoompan(z=1, d=2)
    .output('output.mp4', pix_fmt="yuv420p", vcodec="libx264")
    .run()
)

will produce 250 frames, 10 seconds video. If I set 'd' to 10, it will loop 10 times. If I make 'z' look more realistic, it will do what 'd' is supposed to do, but in addition will loop. I tried different inputs and outputs, reproduces every time. Running same with ffmpeg CLI work normally.

What am I doing wrong?

[furmanlukasz]

Having the same issue, the zoompan function makes more frames than is set in the original file, after finishing it looks like slow-motion fx. Even if I set the zoom to default so it should not change anything.

[lbarraga]

same issue