[pulseaudio-discuss] Getting a null sink to show up as an ALSA device.

[Chris]

For the list archives.... I had things inside out and upside down for
a while, but finally got things sorted.

What I wanted was a virtual audio cable to pipe output from one app
into a device that could be set as the input for another app.  The
answer was module-null-sink and here's how I have it plumbed.

My platform is Ubuntu 11.10, though this is fairly generic.

My ~/.asoundrc

pcm.pulse {
   type pulse
}
ctl.pulse {
   type pulse
}
pcm.!default {
   type pulse
}
ctl.!default {
   type pulse
}
pcm.vac {
   type pulse
   device vac
}
pcm.vacmonitor {
   type pulse
   device vac.monitor
}

In /etc/pulse/default.pa  I uncommented and edited one line

load-module module-null-sink sink_name=vac

The end results

amixer -i
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch pswitch-joined penum
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 65536
  Mono:
  Front Left: Playback 22037 [34%] [on]
  Front Right: Playback 22037 [34%] [on]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch cswitch-joined penum
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 65536
  Front Left: Capture 19194 [29%] [on]
  Front Right: Capture 19194 [29%] [on]

pactl list short sinks
0       vac     module-null-sink.c      s16le 2ch 44100Hz       SUSPENDED
1       alsa_output.pci-0000_01_00.1.hdmi-stereo
module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
2       alsa_output.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00-CODEC.analog-stereo
      module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
3       alsa_output.pci-0000_00_14.2.analog-stereo
module-alsa-card.c      s16le 2ch 44100Hz       RUNNING

pactl list short sources
0       vac.monitor     module-null-sink.c      s16le 2ch 44100Hz
 SUSPENDED
1       alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor
module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
2       alsa_output.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00-CODEC.analog-stereo.monitor
      module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
3       alsa_input.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00-CODEC.analog-stereo
       module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
4       alsa_input.usb-Microsoft_Microsoft___LifeCam_Cinema_TM_-02-CinemaTM.analog-mono
module-alsa-card.c      s16le 1ch 44100Hz       SUSPENDED
5       alsa_output.pci-0000_00_14.2.analog-stereo.monitor
module-alsa-card.c      s16le 2ch 44100Hz       IDLE
6       alsa_input.pci-0000_00_14.2.analog-stereo
module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED


So one app that is properly pulse aware now sees for capture and
playback devices "vac" and "vacmonitor"

My issue now is that the other app I wanted to chain into this does
not seem to have sound implemented completely so it still isn't seeing
it.  However my "mystery" in the config is solved now :-).

-- 
73      de     Chris       KC2RGW
-----------------------------------------------
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