Originally Posted by slizzap
Your Denon screen looks very similar to mine.
In the first picture you can see that the receiver is detecting a Dolby Digital signal, which means it's properly being passed through to the receiver (it's doing the decoding). The only difference between the 2 pictures is that the first one says Dolby Digital and the Dolby Digital logo at the top left is illuminated, and the 2nd picture PCM is being used (Dolby Digital is no longer illuminated, just the PCM indicator is lit). That means your PC is doing the decoding (i.e. you're dealing with a software issue).
At this point I've read enough about S/PDIF, PCM, AC3, stream-wrapping, codecs, encoders, decoders, filters and such that I am beginning to realize just how much there is to learn about multi-channel audio!
I interpreted the Denon's hints essentially as you described, although I'm still wondering about the significance of having a Dolby Digital Logo, the "DIG" box, and a "DOLBY DIGITAL" readout all on the same screen. And what the heck are the "ADVANCED" and "AL24" indicators trying to tell me? Apparently Denon up-samples all formats up to 192kHz sample rates to expand the word length to 24 bits...(?) To me, it's just a lot of quasi-information. I'd much rather see actual information about the audio format. But I digress...
The AC3 test file from me contains a Dolby Digital audio stream, and so when you play it the front of your receiver should look the same as your first picture. I bet if you load XBMC and play that same video file, you'll see Dolby Digital kick in. XBMC uses its own set of codecs, no tweaking required...just enable HDMI output and make sure AC3/DTS are enabled. If it works there, but not in media player, you'll know it's software-related.
Well, for what it's worth, I did load XBMC and at least one of those pictures was taken while playing the AC3 test file with XBMC. I was thinking that it was example1, but many things transpired that evening and I didn't take notes, so I could be mistaken. I'll try to check it again this evening.
I can tell you this though - no matter which player I use to play the AC3 test file, it does not render entirely correctly. One has 5-channel surround, but no subwoofer output while the other produces only 2-channel, but the subwoofer test is audible. None of the half-dozen or so players on my HTPC produced both 5-channel and subwoofer audio at the same time. And in all cases, the Denon was showing the LFE, FL, C, FR, SL, and SR boxes all lit up, even as certain channels were silent.