This has bothered me for a while.
I have seen a lot of "creditless" version of songs and show opening and anime opening in youtube.
How do they remove the credits? Is it in a different layer or something? Some kind of masking?
Is it even possible? If not, how do they do it?
Not sure, but my guess is that either the credits are stored as a different layer or the studios release creditless versions. Masking wouldn't produce the quality you see in most of those.