(starting a new cross-mailing-list thread following some small
discussion on this topic on alsa-devel)
Background:
Many recent graphics cards support sending an audio stream over HDMI or
DisplayPort. This is supported by an HD-audio controller built into the
graphics card.
It'd be nice if
Christopher K. wrote at Monday, February 21, 2011 5:46 PM:
...
My second question is about sound over hdmi with an Nvidia GTX460
(NVC4 /GF104 family):
aplay -L gives
hdmi:CARD=NVidia,DEV=0 - pcm3p/
hdmi:CARD=NVidia,DEV=1 - pcm7p/
hdmi:CARD=NVidia,DEV=2 - pcm8p/
pl bossart wrote:
What I'm talking about is that pulseaudio is incapable of ever sending
audio to anything other than the default device/subdevice within a card,
irrespective of whether a cable is plugged in and signal being transmitted.
ok, I am not sure I understand why there are
Recent NVIDIA GPUs include an audio controller that hosts a number of
different ALSA PCM objects. For example, consider the following output
from aplay -L:
hdmi:CARD=NVidia_1,DEV=0
HDA NVidia, NVIDIA HDMI
HDMI Audio Output
hdmi:CARD=NVidia_1,DEV=1
HDA NVidia, NVIDIA HDMI
HDMI
pl bossart wrote:
If I hack /usr/share/pulseaudio/alsa-mixer/profile-sets/default.conf to
change hdmi-stereo's device-strings value to e.g. hdmi:%f,0, hdmi:%f,1,
etc., then I can cause pulseaudio to open whichever subdevice I wish. This
proves to me that this is simply an enumeration issue