I'm using one of the common 3D software to animate this video.

I have included screenshot of what I'm trying to do.

The animation is as follow:

A stock video will first be revealed.

Then, the video will zoom out. As it zooms out, it will start appearing in a ball. The video is entirely enclosed in the ball.

I've already modelled the ball and the tree. I just want to know how I can animate the stock video to be within the ball. Please, help with explanation.

Thanks.

I think you can do all that with a little motion tracking and masking in adobe premiere pro or after effects

Thanks very much. I'll check them out.

It looks simple. I am not a graphic designer but just paste a picture over it and reduce transparency to almost 2%. It does look like animation or even 3D.

Just search for how to motion track and mask in after effects on YouTube, you'll get pretty good ideas from watching a few videos.
When you done, you could just embed your stock videos in those balls. You'll have to experiment with the blend modes and transparency level. That should let you achieve something close or the same. I hope this helps.

Thank you very much. I'm working on the tips.