Can I use pir sensors to start a video?

Hi, so my idea for an art piece simply is this: A screen mounted on the floor where you see a persons feet standing close to the camera. And when you as a spectator move towards the video piece the person in the video moves backwards. And the person in the video moves closer to the camera again as the spectator moves away.

Is this possible to do this with arduino and pir sensors? Ive never worked with this technik so I´m really a newbie. I understand that I can use Max msp to play the video files right? Has anyone tried doing something like this?

I haven't bought the technic yet, so please tell me what i need to buy for this project.

Thank you in advice

Generally speaking, if you want to do something that's computationally expensive or requires a significant UI, and video is both of those things, it's easier to use a Raspberry pi. A pi would do this very easily and you could have it working within minutes using the PIR sensor and OMXplayer software.

You can use a PIR sensor to start world war 3. You have to divide your task into several sections. First you have your PIR sensor, which reads the spectator's position. Your PIR sensor sends information about that to next section. What is the information? The distance to the screen? Or also sideways movement? Or also which leg is moving? You might need more PIR sensors. The receiving device could be an Arduino, which only translates the sensor readings to say XY-coordinates, or just Y-coordinates. Arduino could send this as serial data to a computer, which in turn could create the animated person walking in the screen. Or have the computer start the prerecorded video sequences. Or start world war 3.

Well, thanks! I'll try them. Are these paid programs?