number of output channels over hdmi

[V_J]

Hello,

Strange question... in the properties of e.g. the HDMI audio output device, you can select the speaker configuration. This selects if it should output stereo, 5.1, 7.1, etc. I can see on an indicator in my receiver that it receives the channels selected.

• If I set this to 5.1, and I play a 5.1 source, everything is fine: 5.1 channel sent to receiver, receiver plays 5.1.
• If I set this to stereo, and I play a stereo source, everything is fine : 2 channels sent to receiver, receiver plays 2 channels (or depending on the select surround mode, distributes over more channels).
• If I set this to stereo, and I play a 5.1 source, only 2 channels are sent to the receiver. (not ideal; receiver can distribute over more, but it is pointless to throw away the original channels)

So this seem to tell me that the 5.1 is the way to go. However:
If I set this to 5.1 and play a stereo source, the receiver indicates it receives 5.1 channels, but only the left and right main channels carry sound. As the receiver gets a 5.1 signal, the surround modes that work to redistribute a stereo signal have no effect. It only has an effect when the receiver indicates it gets 2 channels. So ideally, I would want to use 5.1 only if the source is 5.1 and stereo if the source is stereo (to allow the receiver to deal with it).

Any suggestions on automating this?
One idea would be to always send 5.1, and have the player upsample a stereo signal. But I feel the amplifier is better at this.

The next idea would be to adjust the output channels in the properties of the hdmi output, based on the source that is playing. But I'm not sure that is possible.

I think a workaround could be:
1. also connect optical from soundcard to receiver
2. set hdmi output on computer to 5.1, set optical out to stereo
3. select optical signal on the receiver if the source is stereo, set hdmi audio on the receiver if the source is 5.1 (my receiver supports choosing a different audio channel)
Then it would be a matter of detecting the source (stereo/5.1), and choosing the output to optical / hdmi.
To detect the source would require some file info program / data from the player, changing the output also is a player setting. I'm currently using MPC-HC, but the file statistics are not available from Eventghost, neither is the output setting.... Output setting is available from commandline, but I don't think it works on the fly to modify an open instance (need to test this).

Any other suggestions?

Thanks!

J├Ârg

[V_J]

I read a bit more on it, and it may be possible with Wasapi or Ac3Filter, to automatically adjust the output channels (no need to do it via EventGhost)... Still learning though.

[blaher]

XBMC with the HDMI WASAPI setting does what you're after.

[V_J]

It is a bit difficult to find information on how the whole wasapi thing works, and all software still seems to default to Directsound

Thanks for the confirmation!
I managed to run some tests with Winamp and the Maiko Wasapi plugin, and it is indeed what I'm after. It allowed me to send a stereo signal, regardless of the windows settings.
I am at the moment still using MPC-HC, and the ReClock software can be used to set as an audio renderer that uses wasapi. While I'm still working on the whole setup, I will need to decide on an interface for watching movies (so far, nothing fancy). I used to use MCE+Mediabrowser+MPC HC, but also liked MediaPortal. Never really got into XBMC, but I should check it out again: it supports all I need in one package.