What software i need to compress or shrink the bytes of copied movies from dvd to hard drive or external?

If i copied a dvd to my hard drive, lots of bytes needed to download the movie in my hard drive, the advantage of the movie downloaded its clear same as the original copy but the problem is it occupies to much bytes in my hard drive. what software i need so that if i copy again a dvd it wont eat too much space in my hard drive? its doesnt matter if commercial or freeware i just need it.