[draggy]

I've been looking around but I can't seem to find an answer in any of the typical audio threads.

I have a htpc running Karmic with the xbmc svn ppa. I am using a Geforce 9400 GT PCIe card with the audio over HDMI which connects to my motherboad's SPDIF output.

I have a 5.1 audio receiver DTS capable, etc. My HTPC connects to an hdmi in on the back of the receiver.

I have set the passthrough to IEC958 in the karmic sound control. I have removed pulseaudio to cut down on the problems.

In XBMC I can set the audio to analog with the default audio device and I can get stereo sound.

If I set it to digital, and select the default, then select iec958 (or hdmi) as the passthrough, and UNCHECK DTS and AC3 I can get sound.
If I set to downmix multichannel audio to stereo in xbmc, I get sound in all of the speakers, but it's not surround sound. If I do not downmix, I only get sound from the front left/right. When playing a DTS track, I get f-left, f-right, but no center, so I can't hear any voices.

Why can I not select DTS + AC3 in XBMC? When I select either of them, playing a DTS track results in silence.

Maybe the reason I have no center audio when not downmixing is because it's not passing the DTS track correctly?

In Karmic's control panel, it says my IEC958 device is stereo, but I thought it could still pass multi-channel sound through it?

Does anyone have any thoughts?

if I run speaker-test -c 5 I can only get sound from the f-left and f-right speakers

[draggy]

I've upgraded alsa to v1.0.21 as suggested in the multichannel audio sticky. I also tried using some of the mentioned conf scripts, but I was still getting the same 2 channel audio, so I reverted the scripts, and kept the new alsa version.

aplay -L

Code:

default:CARD=CK804
    NVidia CK804, NVidia CK804
    Default Audio Device
front:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804
    Front speakers
surround40:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804
    4.0 Surround output to Front and Rear speakers
surround41:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=CK804,DEV=0
    NVidia CK804, NVidia CK804 - IEC958
    IEC958 (S/PDIF) Digital Audio Output
null
    Discard all samples (playback) or generate zero samples (capture)

aplay -l

Code:

**** List of PLAYBACK Hardware Devices ****
card 0: CK804 [NVidia CK804], device 0: Intel ICH [NVidia CK804]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: CK804 [NVidia CK804], device 2: Intel ICH - IEC958 [NVidia CK804 - IEC958]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

all of my iec958 devices are unmuted in alsamixer, and channel is set to 6.

MP3 will work if I downmix to stereo, but I still can't get DD, DTS, or AC3 tracks to work with AC3 and/or DTS checked in xbmc settings.

[draggy]

With my spdif over hdmi (geforce 9400GT), here are the settings I've been trying:

Digital
AC3 [X]
DTS [X]
default
passthrough: iec958
downmix [X]

mp3 works; dd(ac3) and dts do not

Digital
AC3 [X]
DTS [X]
default
passthrough: iec958
downmix [_]

mp3 works; dd(ac3) and dts do not

Digital
AC3 [_]
DTS [_]
default
passthrough: iec958
downmix [X]

sound on all track types, but stereo only

Digital
AC3 [_]
DTS [_]
default
passthrough: iec958
downmix [_]

Left and Right channels work, but no center channel on DTS or DD, so I don't get any voices.

If I use hdmi as a passthrough, which is on the list, it fails to initialize the audio device.

If I run speaker-test -c 5, I only get sound from the front left/right.

I know the speakers work, as my 360 has dts 5.1 enabled, and xbmc will play stereo sound out of the center channel if it's set to downmix with no dts or ac3.

Anyone? thoughts? suggestions? I'm at a loss here after reading tons of audio posts.

[sdellutri]

I had lots of problems getting ac3 and dts passthrough to work consistently with Ubuntu Karmic. I think it has something to do with its PulseAudio sound system. I switched to Xubuntu Karmic which I dont think has the pulseaudio, and now its all working great for me.

[draggy]

I've uninstalled pulseaudio to avoid any problems, so I don't think it's that.

[draggy]

For my testing purposes, I installed xubuntu karmic x86 on another partition and started clean. I enabled iec958 in my sound panel, and made sure the volumes were up. With the default settings, I have stereo sound, I can enable digital, disable ac3 and dts, and enable downmix and I will still have sound in all speakers just like before.

I've tried following this guide, for both iec958 and hdmi versions http://forum.xbmc.org/showthread.php?tid=58216 both result in no sound at all. As soon as I remove my asound.conf I can hear again, but of course no dts/ac3.

I've also tried http://wiki.xbmc.org/?title=XBMC_for_Lin...dio_issues using hw:0,1 which does nothing for me. I think I'm supposed to use hw:0,1 ...see my previous post for my aplay -l

Each time I've tested I've tried multiple combinations of enabling/disabling ac3, dts, and downmix.


One odd thing I've noticed is I've seen people say unmute all 4 iec958 settings in alsamixer. But if I turn up "IEC958 P" I lose all sound completely.... not sure what the P is for...

[andocobo]

Hi guys,
I use ubuntu 11.04 and xbmc 11 (eden). I had no audio coming through when i played dolby sources through xbmc, so no audio for dolby pro logic, dolby digital etc., only regular 2 channel stereo had sound. The problem i had was that ubuntu wasnt detecting the nvidia geforce 9400gt as a sound source, even though it was outputting audio through it when it was basic stereo - ubuntu was confused, i think it was trying to play digital sources through the onboard intel sound care or something, not really sure.

Anyhoo, I uninstalled pulse audio, then went and turned off the built in intel sound in sound preferences and then set the audio device and pass through device in xbmc to iec958. Now ubuntu doesnt detect any sound cards at all, but despite this it outputs all sound through the hdmi port of the geforce 9400gt perfectly. I don't really know why it works, but it does - all sound sources are working fine now, although i dont get any menu sounds in xbmc, but that doesnt bother me, at least all the movies and music work perfectly now.

Hope this helps someone out there!