FFMpeg Effect Zoom In and Zoom Out Video File

Question

I need to implement the effect of zooming in and out for video.

Two operations are needed. The first operation is to set the zoom to zero at the beginning of the clip, and by the end of the clip the zoom was gradually increased twice.

The second operation is that at the beginning of the video the zoom is equal to two, and by the end of the video the zoom should be zero.

That is, it is necessary for the zoom to increase / decrease smoothly throughout the entire duration of the video.

I know that Zoompad effect is used for this, but I could not use it for video.

Thank you all in advance for your help!