sensor controlling media player?

Hello, I'm in a class that revolves around using the Arduino. For my project I want to control video playback. At the most simple I want to start with one video which loops and then using a senor a different video plays through. when that video is over the first video continues to loop again until the sensor is activated.

My instructor said this would be possible with the Arduino and Processing. Other than that my instructor doesn't seem to be much help. I have searched and searched for examples of video playback being controlled with the Arduino with no success. Im going to continue reading about processing and asking around the school here.

Thanks for any help.d

video playback being controlled with the Arduino

All the arduino is is a serial device so first of all look for examples of how to play back video in your chosen environment.

Then look to see how you can read the serial port in that environment.

The final step is to get the arduino to send something along the serial port and have your environment respond to that.

If you are looking for someone who has already done it all you are not learning much are you?

Here's a couple links that can get you started.. but the first one is awesome.. you can turn your Arduino into a Keyboard by just plugging it in!
The program will respond to Serial.print, so using Serial.print("Hello!");
Will type that just as if it were a keyboard. Also, Serial.println("Hello!"); will first type, then push enter key (Serial.println)

The second link will work with regular keyboards as well, but you can program it to do ANYTHING on a button press.
For example, I was controlling Windows Media Player via RF remote I made with my Arduino.

http://www.aacinstitute.org/Resources/ProductsandServices/AACKeys/AACKeys.html

Auto hot key can also move your mouse if you push a button on your Keyboard (or arduino).