Adding effect to video.

I created a gif image of a flashing "rec" to add to a video project to simulate a record light. How can i add this over a video? Can i do this in imovie or quicktime? I realize programs like final cut can do this but i dont own that software.

 

Thanks for the advice.. I may have to purchase it, i hear it's worth it, Thanks again!

 

**Just a follow up**..
I was able to get the results i needed with photoshop and quicktime.. It turned out better than i could have imagined. If anyone is interested PM me and i'll explain. Thanks for all the responses.