[thedingo]

A couple of weeks ago I swapped out my old receiver for a new one that supports HDMI. My previous method of hooking up my XBMC was over HDMI to my TV (which handled my HDMI switching) and passed to my stereo using an optical out. Now the HDMI runs directly to the stereo itself.

The issue I am seeing is that it appears random bits of content are no longer playing back audio. When audio does work, the receiver displays "Multichannel PCM" and when it does not, the receiver displays nothing as if it is getting no audio information. I have checked some similar content and found that both contain MPEG2 audio (at different bitrates), but only one will work. Is the issue that the audio is not getting decoded before passing down and in these cases the receiver is unable to decode? Is there anyway to ensure that all decoding is done on my HTPC and sent multichannel to the receiver? I have tried every combination of the three audio settings (DTS, DD, Downmix to stereo) and saw no difference.

Here is my setup (the important part anyway):
Windows XP SP3
Nvidia 9400m (latest drivers from Windows Update)
Onkyo TX-SR507
Latest XBMC build from XBMCUpdate (though I have confirmed this issue with the latest stable 9.04 as well)

[thedingo]

Anyone?

[Dullie]

Why dont you bitstream audio from your HTPC to your new AVR through HDMI, and let it handle the decoding.. Receivers are much better decoders than HTPC..

And you might want to try new drivers for your Audio Card. I had issues with sound cutting off and coming back before. But when updated the drivers all went fine..

What is your sound card..?

[thedingo]

I assumed I was doing a bitstream as I have DD and DTS turned on. Are there any other options I am missing?

My drivers are all up to date as per Windows Update, though I can try newest ones through the partsmakers. I do doubt that is the issue though because this problem first showed up when I switched to this new receiver.

The sound is being provided via the HDMI output from the Nvidia 9400m chipset (at least the output device indicates "Nvidia High Definition Audio Output"). The other onboard sound chip is from Realtek, but it looks like that only handles the analog and dedicated digital outs, with Nvidia handling the HDMI output.

EDIT: And if it makes any difference, I did switch my dedicated Blu-Ray player to bitstream and it is working fine, so I know the receiver is handling some decoding just fine.

[Dullie]

Windows Update is the worst place to look for drivers..

go to nVidia website, and download the latest driver..

To bitstream audio from your HTPC with XBMC, go to settings, system, Audio Hardware, choose Digital as Audio Output, then tick Dolby Digital capable Receiver, and DTS capable receiver.. I am assuming you have 2002 + Receiver cause they all do have DTS and DD decoding capabilities.. 2007 + have Dolby True HD, and DTS HD Master Decoding capabilities..

Anyways, now when you play a video containing DD or DTS your receiver front screen should say DTS or Dolby Digital.. When it says Multichannel PCM it means that it is not handling the decoding, and the source is sending audio already decoded as PCM..

By the way, I think your receiver is a Denon..

[thedingo]

Sadly I am already using Digital/DD/DTS as my settings. The receiver is Onkyo: http://www.onkyousa.com/model.cfm?m=TX-S...ceiver&p=i

[joshuass]

Most HDMI output coming from graphics cards do not output multichannel PCM. Its either Stereo, DTS, DD, or the HD variants of it.

You'll want to make sure that in the Audio settings for windows that you passthrough DTS and DD streams. And make sure your speaker configuration is Stereo (you might have a 5.1 setup, but again, your graphics card most likely isn't capable of outputting multichannel PCM via hdmi).

Next, you'll want to make sure the DD and DTS capable receiver settings are checked on in XBMC. Its probably a good idea to check on "downmix to stereo" too. This is going to downmix AAC and other off formats down to stereo since VERY few receivers can natively decode those.

If everything is set correctly, you should have stereo sound from your receiver (shows up as "Stereo" or some PLII format like "PLII Theater" or "PLII Music") for all formats except DD and DTS. DD and DTS should switch your receiver to DD or DTS modes.

This has worked flawless for me (I have an Onkyo TX-SR605) and ATI Graphics.