Quote: "Hello there, I've no any knowledge about the copyright laws so I ask your help !"
Quote: "Wow, seems it's very complicated."
To make short about copyright laws, (1) if something is copyrighted (a song, writing, etc), you
cannot use it without the original author's permission; UNLESS you can find a license for the original piece that says otherwise.
In this case (using a remix of a copyrighted piece), you still need permission from the author of the original work. For example, you CANNOT use a cutscene in your game made by 'Joe Smith' on Youtube, which was nothing more than a compilation of mildly edited scenes taken from The Dark Knight, because the content in those scenes from Joe's video are copyrighted.
If you've ever seen user videos on Youtube, which don't have any audio in them, with a statement; "The audio for this video has been removed due to a copyright claim by ...", it's the same thing. The original author took action against his work being used without his permission, and the audio was removed.
(2) If you're unsure about a license, or if you can or can't use this or that; the safest thing to do is simply not use it.
Kravenwolf
