When using straight HDMI output, my Amp read it as 'PCM Audio' but when using 'Encoded HDMI' it read it as 7.1 DTS Audio giving the sample rate and bit rate. To my amazement it worked!! - I got glorious 7.1 DTS-MA into my Amp, and it sounded simply stunning!! In VLC I had two HDMI audio devices to choose from 'HDMI' and 'Encoded HDMI' (or something like that - I'll have to hook it up again to be sure). I tried opening them up in VLC media player (version 2.1.5) and hooked up my 2014 MacBook Pro via HDMI to my Amp. Therefore out of curiosity I decided to download a couple of HD demos from that have DTS-HD MA 7.1 audio tracks embedded in them. However, I realised my work laptop is a 2014 MacBook Pro with HDMI out. I was quite happy with this arrangement, until I get around to buying a blu-ray player. Up until now I've not been able to try this sound format out as my current 2009 Mac Mini only sends audio through the Optical Out, so the best I can get is Dolby Digital 5.1 pass thru via S/PDIF. It handles DTS-HD Master Audio 7.1 and Dolby TrueHD 7.1.

I've just bought a new 7.1 Amp, the Yamaha RXV677 from Richer Sounds. I know this thread is a little old now, but I've been wondering the same thing myself - so I googled it and came up with this thread.

Play sound through hdmi for mac