"It's not that I'm knocking the movie and television work"

George Peppard is expressing his appreciation for the work he has done in movies and tv. He is not trying to criticize or belittle the work he has done, but rather to emphasize that he is grateful for the chances he has had. He is acknowledging that the work he has actually done in the show business has actually been important and has actually provided him with a platform to showcase his skills. He is also revealing his desire to check out other opportunities of acting, such as theater, and to challenge himself in brand-new methods. He is not trying to discredit the work he has actually carried out in movies and tv, but rather to highlight that he is searching for brand-new opportunities to grow and develop as an actor.