[LINUX] HOW-TO get Digital Audio Pass-Through Output working on Linux with XBMC

mowgli80 Wrote:I have been able to get it working for intel HDA cards on two systems

o Make pulseaudio output go to analog out
o in alsamixer, unmute spdif and spdif default pcm

This way, I easily get both passthrough and pulseaudio working smmothly side
by side.

Thanks for the super tip. How exactly did you setup PA to use alalog out? Doet PA have a setup prog?

I noticed in your first post that you said you weren't able to to get passthrough working on Live. I believe I know how to get passthrough to work on Live (Dharma beta 3 tested) on an ION-based box (I've used two Revo 1600 boxes to test this) via HDMI connection.

1) SSH into your box, then type the following:


2)


3)


4)


5) In the system audio settings, I believe everything is set to HDMI (including passthrough device) and then make sure the DTS (and whatever the other one is) is checked.

6) Reboot

Works now?

@Alexpigment: thank you very much for the Howto. Do you know how it works if one does not have an intel soundcard, but a C-Media CMI8738 based one?

is there any sense to use passthrough for mp3/aac streams ?
Does passtrough improve the quality of sound in this case ?

Wow i've been struggling for hours/days to get XBMC with DTS working on my ION system which is connected through HDMI to my Denon receiver. All i've tried failed but removing pulse audio seems to work a little bit. Cause when i start a DTS movie i have DTS sound, but the image is stuttering so hard that its impossible to watch.
But before i removed pulse audio the image was smooth but just no DTS sound.

Still i don't know how to fix it

Wimploo Wrote:Still i don't know how to fix it

http://forum.xbmc.org/showthread.php?tid=34655

alexpigment Wrote:I noticed in your first post that you said you weren't able to to get passthrough working on Live. I believe I know how to get passthrough to work on Live (Dharma beta 3 tested) on an ION-based box (I've used two Revo 1600 boxes to test this) via HDMI connection.

1) SSH into your box, then type the following:

Code:

sudo apt-get update

2)

Code:

sudo apt-get install wget

3)

Code:

sudo wget http://pastebin.com/download.php?i=f5f9654bb -O /etc/asound.conf

4)

Code:

sudo wget http://pastebin.com/download.php?i=f2e38265 -O /usr/share/alsa/cards/HDA-Intel.conf

5) In the system audio settings, I believe everything is set to HDMI (including passthrough device) and then make sure the DTS (and whatever the other one is) is checked.

6) Reboot

Works now?

Running Dharma Beta 4 Live, I tried all these steps on asus AT3ION-I Deluxe and cannot get audio via HDMI. Without these steps, I can get audio via spdif and only get "static" via hdmi. After these steps applied I get the same behavior. So no go on AT3ION-I.

tafypz Wrote:Running Dharma Beta 4 Live, I tried all these steps on asus AT3ION-I Deluxe and cannot get audio via HDMI. Without these steps, I can get audio via spdif and only get "static" via hdmi. After these steps applied I get the same behavior. So no go on AT3ION-I.

1. You're usng the 'live' variant of xbmc: one may read in my first post that I didn't get it to work either w/ s/pdif.

2. HDMI audio? Depends on the status of your hardware driver. I am under the impression that hdmi audio out (= dig. au. out) is still being very actively developed by the various driver programmers. See if you can find a website or forum topic anywhere (Google!) on your specific hardware setup. You may have to upgrade (software or drivers) to get it to work.

Good luck

P.S. Added the following remark to my top post:
"Geting dig. au. out via HDMI seems to be difficult too. I do not own hdmi hardware so I heve no personal experience w/ that. But it seems to me that drivers for the hdmi part of video cards are still in active development and that it depends on Alsa supporting it. A separate sticky How To about hdmi and dig. au out may be necessary."

I wanted to add my experience and thank the OP for this awesome thread!

Following the directions in Ubuntu 10.10 produced the expected results. I could get audio and passthrough, but no menu sounds. Also Mupen64Plus did not work at all after removing pulse (it didn't have sound in the first place).

The magic touch was this:
Note: Installing that will also remove libsdl1.2debian-pulseaudio

But once libsdl1.2debian-alsa was installed, mupen64plus worked, and so did all of the xbmc menu sounds, as well as mp3s, and digital passthrough. Amazing!!!!



Under Ubuntu 10.10, here were my steps to get my SPDIF passthrough (to hdmi) working with all sounds:
removed ~/.asoundrc
sudo apt-get purge pulseaudio gstreamer0.10-pulseaudio
sudo apt-get autoremove
sudo apt-get install alsa-base alsa-tools alsa-tools-gui alsa-utils alsa-oss linux-sound-base alsamixergui
sudo apt-get install esound esound-clients esound-common libesd0 gnome-alsamixer
sudo apt-get install libsdl1.2debian-alsa

reboot

run gstreamer-properties
Plugin: alsa
Device: default

xbmc settingsOptical/Coax
Audio Device: Defaults
Audio Passthrough: plughw:0,0