I want to test out some of the Dolby Atmos trailers to test my DN1080 and dial in settings. I have a PS3, which is too old. I have a Roku Ultra, but can't find any channels on it that have a demo. I have a Macbook Pro with a USB-C to HDMI cable that I use to hook my computer up the the TV sometimes. I thought that might be my best bet. When I play one of the downloaded Dolby trailers in MP4 format, the receiver only detects 2-channel stereo. I tried playing the video from iTunes, and VLC, and same result. I tried messing with audio settings I read about on various websites, but nothing shows 5.1, only 2.0. I don't know if it's my Macbook settings, VLC settings, or maybe USB-C to HDMI doesn't allow 5.1? I also tried Airplay, which played audio, but only 2.0. Any ideas?