It's a little tough not knowing exactly how your hardware is working and sending in info, but if it were me, I'd probably just assign a boolean variable which allows access to the sensor status, and pair that with a timer which correlates to your video playback. So here's some code/pseudo that demonstrates what I'm thinking:
Code:

int sensor_status;
boolean movIsFinished = true;

if(movIsFinished){
     sensor_status = somehardware.getSensorStatus();
     movIsFinished = false;
}
if(sensor_status == 0){
     play movie;
     if(check_to_see_if_movie_is_finished_playing){
          movIsFinished = true;
     }
}
 

So basically, you're only updating your sensor_status variable when no movie is playing. That way, although your hardware is constantly sending in numbers, your system will ignore them until you need to check on them again, i.e. when your movie is finished playing. There are a few ways you can check to see if your movie is finished. You should check those out at the video library page. I don't know, is this the type of answer you were after