I find that strange because the movie I ripped a couple of days ago that lead to my discovering this issue has a DD 5.1 soundtrack. So why did asking MC21 to output DD cause it to shut-down when asked to play a movie, or bring up an error message when asked to output redbook 16/44.1 stereo?
I'm not really sure. That option is sort of unusual. It's designed to take everything that MC processes and stick it into a Dolby Digital container, re-encoding everything on the fly. This wouldn't be necessary just to play DD content. MC decodes DD and sends it as PCM. That option would have your DD5.1 soundtrack get decoded to 5.1 channel PCM, then *re-encoded* back to Dolby Digital and sent out via your sound output device.
Why does this option exist? It's designed for sending multi-channel audio across interfaces that only support 2 channels, when you really, really want to send 5.1 channels. Like optical digital connections for example. Optical digital can't support PCM for 5.1 channels. It does stereo PCM, but not 5.1 PCM. So you tell MC to re-encode everything into a Dolby Digital stream and *then* it can be sent out over optical digital. Of course this all requires your receiver to be able to decode the DD stream, so it can be played.
I suspect that it doesn't work for you because MC still can't "see" your receiver and it doesn't think that DD will be accepted.
Correct me if I'm wrong, you can't play 5.1 from ANY source via HDMI right? (VLC, Mac DVD player, etc) So it's not really an MC specific problem, but rather a Mac + HDMI + AVR problem?
Good luck in any case.
Brian.