Compositing Question. PLEASE HELP!!!!!!!!!!!!!

Ive seen a lot of videos around youtube lately of people adding effects to video using blender. But can It go the other way? Like is it possible to do something like, put a video of a person into a background made with blender? Can you kind of “cut out” part of a video? Like say I have a video of a person walking down the street. Can I cut the person out of the street so I have just the person?

yes, it’s called pulling a matte. You can buy my book which explains it, or see the tutorial I wrote http://wiki.blender.org/index.php/Doc:Tutorials/Composite_Nodes/Setups/Blur_the_Background for a very brief overview. To pull a matte from a video that you cannot key, you will have to rotoscope. I published a video tutorial on that as well on Vimeo in my SFX series. Look up PapaSmurf on Vimeo. Enjoy.