[jubilex]

My receiver is a Yamaha RX-V2700 7.1 channel receiver which supports multichannel LPCM over HDMI. It also decodes DTS and AC3.

Running Gotham beta 3 on Windows 7.

Under Audio Output, with channels set to 7.1 and passthrough enabled, I do not have an option for Multichannel LPCM capable receiver as shown here: http://wiki.xbmc.org/index.php?title=Tal...o_settings . This option must have existed in previous versions of XBMC, as my old advancedsettings.xml that I used with a previous XBMC version has <multichannellpcm>true</multichannellpcm> in it, and I swear I remember seeing "multichannel LPCM" as the audio source on my receiver's display back in the "good old days".

As a result, the only way I can play back FLAC 5.1/7.1, or DTS-HD or TrueHD, is to set my channels to 2.0 and enable Dolby Digital transcoding in the passthrough section. I would think this transcoding would result in worse sound quality than sending straight LPCM and be more taxing on the PC as well.

What am I missing?

[jjd-uk]

The GUI option was removed but xbmc still does Multichannel LPCM as internal logic now dictates when it is used.

Simply set Audio Output Device to HDMI and Number of Channels to 7.1 and flac 5.1/7.1should be passed, if you want DTS-HD/TrueHD decoded to Multichannel LPCM then disable those options.

[jubilex]

Yes, that's what I have. Audio device is Directsound-HDMI-yamaha, 7.1 channels, best match; passthrough is enabled; passthrough device is WASAPI-HDMI-Yamaha, DTS and DD enabled. I'm only getting Left and Right PCM channels output from 5.1 and 7.1 FLAC (haven't tried other HD sound formats yet).

Here's a debug log of an attempt at playing a remuxed Gravity with FLAC 5.1: http://tny.cz/07244346

[jjd-uk]

Try with Audio device also set to WASAPI-HDMI-Yamaha

[jubilex]

That did it, thank you very much! Iirc the reason I switched to the combo originally some time ago was because having both as WASAPI caused some kind of performance issues or something with some material. I know there's some reason I did it. I guess I'll find out as I go through my library.

Why doesn't directsound pass multi LPCM? I thought WASAPI was only required for HD encoded audio formats.

[jjd-uk]

Basically:

WASAPI: XBMC <-> Windows Driver <-> Audio Device

Directsound: XBMC <-> Windows Audio Mixer <-> Windows Driver <-> Audio Device

So with Directsound the configuration of audio devices within the Windows can have an effect.

The log reports Directsound the HDMI as 2 channel only, do you happen to have Speaker Setup in Windows set to Stereo? see Step 4 at Windows_Settings_for_AudioEngine (wiki)

[jubilex]

That was it. Thank you! Not sure how, when, or why my Windows sound settings got changed....

[vicmanpergar]

That was it. Thank you! Not sure how, when, or why my Windows sound settings got changed....

The Windows sound setting will change randomly, it's a known problem on HDMI handshaking. Happens everytime u turn ur TV and/or AVR on.
I got the habit of always checking the speakers settings for 5.1.
If u have the Yamaha ARC HDMI Control on, may be u could trade turning on TV and AVR with one button ability for a more stable handshaking with windows. I turned that off, and found my speakers configuration is not returning to stereo every now and then.

[steelman1991]

Use WASAPI like jjd suggests and it doesn't matter what windows sound does - you'll still get proper playback.

[jjd-uk]

That was it. Thank you! Not sure how, when, or why my Windows sound settings got changed....

The Windows sound setting will change randomly, it's a known problem on HDMI handshaking. Happens everytime u turn ur TV and/or AVR on.
I got the habit of always checking the speakers settings for 5.1.
If u have the Yamaha ARC HDMI Control on, may be u could trade turning on TV and AVR with one button ability for a more stable handshaking with windows. I turned that off, and found my speakers configuration is not returning to stereo every now and then.

I wouldn't called it random as it is always likely to follow a pattern, most likely components being switched on in the wrong order.

[vicmanpergar]

That was it. Thank you! Not sure how, when, or why my Windows sound settings got changed....

The Windows sound setting will change randomly, it's a known problem on HDMI handshaking. Happens everytime u turn ur TV and/or AVR on.
I got the habit of always checking the speakers settings for 5.1.
If u have the Yamaha ARC HDMI Control on, may be u could trade turning on TV and AVR with one button ability for a more stable handshaking with windows. I turned that off, and found my speakers configuration is not returning to stereo every now and then.

I wouldn't called it random as it is always likely to follow a pattern, most likely components being switched on in the wrong order.

Yeah, probably, this is what i read everywhere i searched. However, doesn't always happen that way in my system.
Anyway, as guys said, if u use WASAPI no matter if u have 2.0 selected as speakers configuration in Windows, it will pass the audio as it is.

[jubilex]

I will try WASAPI only, and hopefully whatever problem I used to have that forced me to use DirectSound with WASAPI for passthrough has been fixed in the versions since.

Will also check the Yamaha ARC, if it's on, I don't mean it to be. I control everything with irule.