I think I am doing the same exam as you. Was the breif something to do with planning an action adventure film for Hollywood and winning a trip there?
Anyway I like to revise for media by making mindmaps of all the key termonology which will get you extra marks in the exam. Also listing the big films out, the relase dates and key scenes which you can quote in the exam.
In relation to the breif you can decide what you film idea is going to be. For example you can create a plot idea at home to make sure you know what you are doing in the exam if they ask you to create a stroyboard for the trailer or something along the lines of that.
Also I am making revision nots on media studies soon so you can use mine if you would like to. If you need anymore help just send me a message.