[acribb]

From what I have read, XBMC is supposed to decode Dolby TrueHD and spit it out as PCM to the receiver.

I know my Denon AVR is receiving all the channels correctly, because when I test HDMI 7.1 in Audio MIDI Setup, all the channels check out.

Check out this "Dolby TrueHD Channel Check (lossless) file at this link:
http://www.demo-world.eu/trailers/high-d...ailers.php
It's encoded in Dolby TrueHD 7.1.

When I play this test on my 2010 Mac mini running 10.6.3, what are supposed to be the rear surrounds play on the side surrounds.

The Bit Harvest (Lossless) sample on this same trailer page plays the same way - Nothing plays out of the rear surrounds out of XBMC.

Can someone test this on their 7.1 system?

Also, another strange thing I have noticed is that if you open Plex 9, the 7.1 PCM stops outputting from the Mac and then 2 channel Dolby (left and right channel only) starts outputting instead. When you open up XBMC again, I have to manually set the 7.1 setting in Audio MIDI Setup to get 7.1 PCM working again. Movies with 5.1 dolby digital or dts will bitstream correctly though.

Would someone mind testing this too?

[D-tyme]

I too have had this problem recently, and what I realize is that the center channel is whats missing (on a 5.1 system). If I change to 2.0. I can at least hear the center channel (abit from all speakers).

[acribb]

I too have had this problem recently, and what I realize is that the center channel is whats missing (on a 5.1 system). If I change to 2.0. I can at least hear the center channel (abit from all speakers).

Not sure if this is related to what I am talking about.

My issue is with a 7.1 system hooked up to a Denon AVR via HDMI. On first reboot of the Mac mini, the mini outputs 7.1 PCM over HDMI. When I switch menus in XBMC, the 7.1 pcm is indicated on my Denon AVR. Only 2 of the 7.1 channels emit sound from the XBMC menu sounds, the left and right channel. Seems normal to me. When I play a 5.1 movie, everything works fine as XBMC is bitstreaming the Dolby Digital or DTS to the AVR. But when I play the Dolby TrueHD channel tester, the 6 and 7th rear channels don't work at all. The rear channels play through the side channels. Not sound is emitted from the 6th and 7th rear channels.

Then when I open up Plex, the mini starts outputting dolby 2.0 to the AVR and will output 5.1 when a movie with 5.1 is played, as expected.

When I close Plex, the mini continues to output 2.1 Dolby, even when opening up XBMC. Then when I go back in to play the Dolby TruHD channel checker, only the left and right channel play. I have to go into the Audio MIDI Setup and manually switch back to the 7.1 HDMI in there.

While it seems like XBMC can at least partially handle Dolby TrueHD, its implementation is flawed at best as far as I can tell.

There needs to be code in XBMC that tells the Audio MIDI Setup app on the Mac to switch over to 7.1 HDMI, if the HDMI settings are set to 7.1 in the XBMC settings.

And then the 6th and 7th rear channels need to be enabled in the XBMC code when decoding Dolby TrueHD to output as 7.1 PCM over HDMI.

[D-tyme]

So I guess what I'm saying is...its not just 7.1 systems; as I only have a 5.1.

I'm only referring to Dolby TrueHD, as every other format works. I have an Onkyo/mini/HDMI combo and while it reports that it is receiving Dolby TrueHD, just my fronts and surounds play their part, while the center stays mute (no voice/talking). If I change XBMC to 2.0, instead of 5.1, everything plays from the fronts (like it should). I did this to verify that the Center Channel was indeed part of the track.

So, the bottom line is, the title of this thread still holds true in my situation as well.

[acribb]

So I guess what I'm saying is...its not just 7.1 systems; as I only have a 5.1.

I'm only referring to Dolby TrueHD, as every other format works. I have an Onkyo/mini/HDMI combo and while it reports that it is receiving Dolby TrueHD, just my fronts and surounds play their part, while the center stays mute (no voice/talking). If I change XBMC to 2.0, instead of 5.1, everything plays from the fronts (like it should). I did this to verify that the Center Channel was indeed part of the track.

So, the bottom line is, the title of this thread still holds true in my situation as well.

Interesting.

I will test by setting XBMC to 5.1/HDMI tonight (vs. 7.1/HDMI) and let you know if I have the same issue.

Do you have Plex 9 as well?

**Edit** Your Onkyo should not be reporting that it is receiving Dolby TrueHD, because it isn't. XBMC does not bitstream Dolby TrueHD. XBMC only outputs PCM that it supposedly gets from decoding DolbyTrueHD. Your Onkyo should only read 'PCM' or something like that.

[acribb]

5.1 plays just the same for me as 7.1, since the rear surrounds never did work for me anyways.

I tested out XBMC on a Windows 7 partition I have set up and the Dolby TrueHD 7.1 PCM looks like it is working. All 8 speakers output discrete sound when I play the Dolby TrueHD Channel Check (lossless) test file. However, the side speakers are outputting as the rear speakers and vice versa. Everything is configured correctly according to the Windows 7 audio settings, such as when you select the audio device and then test each speaker.

Conclusion:
PCM sound is wonky on both Windows 7 XBMC and Mac XBMC. And it doesn't look to be too high of a priority right now.

Who are the primary OSX Developers? Davilla? Who else?

I may want to get involved in fixing the OSX version.

[D-tyme]

I suggest you put in a ticket.