you can use chmap to query the channel map http://git.alsa-project.org/?p=alsa- lib.git;a=blob_plain;f=test/chmap.c;hb=HEAD
control.45 { iface PCM name 'Playback Channel Map' value.0 0 value.1 0 value.2 0 value.3 0 value.4 0 value.5 0 value.6 0 value.7 0 comment { access read type INTEGER count 8 range '0 - 36' } } control.47 { iface PCM device 1 name 'Playback Channel Map' value.0 0 value.1 0 comment { access read type INTEGER count 2 range '0 - 36' } } control.54 { iface PCM device 3 name 'Playback Channel Map' value.0 0 value.1 0 comment { access read type INTEGER count 2 range '0 - 36' } } post pulseaudio verbose log when you play AC3 5.1 DVD to your spdif or hdmi you can find the channel matrix https://wiki.ubuntu.com/PulseAudio/Log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1249705 Title: HDMI output not available in 13.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1249705/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs