No matter what we try, my puppy won’t stop growling/barking at animals on TV. What can we do?

My puppy (he is 1.5 so not really a puppy anymore but he acts like it still) growls and barks at anything animal or animal-like on TV. He is a boxer/GSD. We have tried treats, saying no, redirecting him, etc. It has been over a year of this and I can't do it anymore. He also growls/barks at animals outside but that is less annoying because they're at least here. I want to get it all to stop but I don't know what else to try. Does anyone have any advice? I love the dog but this is ruining my peace and rest. Thank you.