[lithiumc]

well i tried 5.1 passthrough, on my zotac ion and it seems to work through hdmi. The only issue I have is dts sources have no speech audio only sound effects. I compiled xbmc without the pulse audio option.

[schumi2004]

I have a custom asound.conf file that you may be interested in and I'll post it below.

With this setup I can have dual audio output from the HDMI port and the Optical port (both on board).

Generally if I'm watching TV I'll use sound through HDMI and it plays through my TV. If I want 5.1 sound through my receiver I'll turn the volume on my tv off and turn my receiver on.

Keep in mind that I'm using on board HDMI and Optical Out. You may have to modify this to fit your needs.

results from aplay -l

Code:

**** List of PLAYBACK Hardware Devices ****
card 0: SB [HDA ATI SB], device 0: ALC889A Analog [ALC889A Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: SB [HDA ATI SB], device 1: ALC889A Digital [ALC889A Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 3: ATI HDMI [ATI HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

asound.conf file

Code:

cat /etc/asound.conf
pcm.!default {
        type plug
        slave {
                pcm "both_digital"
        }
}

pcm.both_digital {
        type route
        slave {
                pcm multi
                channels 4
        }
        ttable.0.0 1.0
        ttable.1.1 1.0
        ttable.0.2 1.0
        ttable.1.3 1.0
}

# Toslink digital_1 output
pcm.digital_1 {
        type hw
        card 0
        device 1
        channels 2
}

# HDMI digital_2 output
pcm.digital_2 {
        type hw
        card 0
        device 3
        channels 2
}

pcm.multi {
        type multi
        slaves.a {
                pcm "digital_1"
                channels 2
        }

        slaves.b {
                pcm "digital_2"
                channels 2
        }

        bindings.0.slave a
        bindings.0.channel 0
        bindings.1.slave a
        bindings.1.channel 1
        bindings.2.slave b
        bindings.2.channel 0
        bindings.3.slave b
        bindings.3.channel 1
}

XBMC Audio Settings:
Audio output = analog
speaker configuration = 5.1
Boost volume level on downmix = off (not really sure what this does)
Audio Output Device = Simultaneous output to RS880 Audio Device [Radeon HD 4200]

If you want 5.1 audio why is channels set to 2 in asound.conf for Toslink digital_1 output?

Shouldn't this be 6 (5+1) or 8 for 7.1 ?