No Audio options for HDMI with 15 inch rMBP

[AdvocateUK]

When I plug my rMBP into my AV receiver via HDMI there are no options to switch the audio to be sent via HDMI.

When I installed the recent SMC update I did finally see an option to send audio via HDMI but then my rMBP froze and after a hard reset the option has disappeared never to be seen again.

I've tried resetting the SMC and NVRAM/PRAM all to no avail, I'm at the end of my tether. If anyone has any ideas how I can get this option back I will be eternally grateful.

TIA, Alistair

 

[AdvocateUK]

Update: I just tried plugging my rMBP into my Samsung TV and HDMI came up straight away as an option for sound output, so it looks like it's a problem with the av receiver. Odd, everything else works great with it.