[alsa-devel] Nvidia HDMI and four codecs

Stephen Warren swarren at nvidia.com
Sat Feb 5 00:25:20 CET 2011

David Henningsson wrote at Wednesday, February 02, 2011 1:04 AM:
> As for PulseAudio, showing four HDMI devices is quite simple [1] but I
> still think it would be a little confusing to show four devices to
> choose from and would wish for something more intuitive.
> ...
> [1] I haven't tested it, but I guess the following addition to
> /usr/shared/pulseaudio/alsa-mixer/profile-sets/default.conf should do it:
> [Mapping hdmi-stereo-extra1]
> description = HDMI out extra 1
> device-strings = hdmi:%f,1
> channel-map = left,right
> priority = 2
> direction = output
> [Mapping hdmi-stereo-extra2]
> description = HDMI out extra 2
> device-strings = hdmi:%f,2
> channel-map = left,right
> priority = 2
> direction = output
> [Mapping hdmi-stereo-extra3]
> description = HDMI out extra 3
> device-strings = hdmi:%f,3
> channel-map = left,right
> priority = 2
> direction = output

This kinda works, but is pretty broken.

I tested on:
* Ubuntu Lucid with all updates
* Your audio PPA, so the latest ALSA kernel driver
* alsa-lib

I tested earlier on Karmic too, and saw the same behavior. Unfortunately,
Maverick is having issues on my test machine, so I didn't test it.

When I log in, there is only 1 display by default, and hence only one pin
complex with valid ELD information (eld#0.0 in my case).

In the Gnome volume applet, Hardware tab, I do see those extra sinks show
up. However, as soon as I select one of the new extra options, the entry on
the Output tab for the GPU gets removed, so I can't actually route audio
over HDMI anymore.

pavucontrol is similar; the Configuration tab shows the new profile, but the
Output Devices tab doesn't show any entry for the GPU.

Now, if I use nvidia-settings to light up another display, in TwinView
mode, there are now two pin complexes with valid ELD information (eld#0.0
and eld#3.0 in my case).

There is no immediate change to the Gnome volume applet or pavucontrol.

However, if I kill the PulseAudio daemon, and let it restart, then both
the Gnome volume applet and pavucontrol start behaving more as expected; I
can use either to change the GPU's profile selection, and audio will get
moved between the two monitors, or /dev/null if I select a non-connected

I assume this is an issue within PulseAudio. Unfortunately, I doubt I'll
be able to find time to look into this in detail.


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