My Apple TV sometimes doesn't negotiate hdmi correctly and ends up without hdcp enabled, and it whines similarly to what you describe. If I switch inputs on the

My Apple TV sometimes doesn't negotiate hdmi correctly and ends up without hdcp enabled, and it whines similarly to what you describe. If I switch inputs on the receiver it'll re-negotiate correctly and everything works again. It's annoying, but it's not necessarily caring specifically about the content you are watching.