What software language/tool/technology allows you to insert a picture into an animated video on a website?

Question

HTML

Specifically, what is at stake - there is a site - www.jibjab.com/holidays , where you can insert your photos into the "dummy" video postcards and they will move in accordance with the animation on the video. How can this be technically implemented? Explain, please, who understands. Googling didn't lead to much success.
Thanks in advance. And Happy New Year =)

Answer 1

Answer 2

Here it is - much cooler: ihero2012.com/newhero.html
1. Initially, there is a binding (pinning) of the rectangular area of ​​each frame from the finished video to the coordinates.
2. We paste the given photo into each frame with distortions based on pinning.
3. And, voila - PROFIT!)