About Summer of code idea -- better big-file support

Hi, there

I am wondering start implementing the idea about better big-file support during summer of code. Here are my idea: often gigantic files is media file, such as rmvb, swf, pdf, dll, etc. And those file themselves are already being compressed, as we all know, git uses zlib to compress all the object in repository, and it is the common sense that if we use zlib to compress those file, the compress ratio will be unbelievable low, from my test if we compress 521MiB mkv file it will be 520MiB after compressed, how ridiculous it is! Also I test that if we use "git hash-object" to calculate SHA-1, and copy all content to repository, it will costs 1 minutes, once we use "git hash-object -w" it will costs 2 minutes. So we sacrificed a lot, but gained a little. So, how do you guys think about that we can test the file type, and then decide to use zlib or not? Cheer Di