Ubuntu Server - Virtual Sound Card

Deleted74295

@thwr said in Ubuntu Server - Virtual Sound Card:

@Breffni-Potter Are you sure? snd-dummy represents a sound card on its own, with no specific hardware behind. I have no real use case for this, but this should work out of the box. If not, I may take a look into it.

The idea behind is simple:
snd-dummy represents the first (and only) soundcard. ALSA (or more likely PulseAudio) will "route" everything through it. From there, you should be able to grab a stream.

https://ubuntuforums.org/showthread.php?t=2119648

I gave up on that linux VM so can't test it but I tried many things under the sun involving ALSA and PulseAudio, I had a real Linux brain box helping me out with it and neither of us could get it working after a week of trying different things out.

If it works in testing by someone else, that'll be nice to know how to get it working.

thwr

@Breffni-Potter said in Ubuntu Server - Virtual Sound Card:

I gave up on that linux VM so can't test it but I tried many things under the sun involving ALSA and PulseAudio, I had a real Linux brain box helping me out with it and neither of us could get it working after a week of trying different things out.

So that's not urgent at all. You made me curious, so maybe I'll take a look into it during the next few days

Deleted74295

@thwr said in Ubuntu Server - Virtual Sound Card:

@Breffni-Potter said in Ubuntu Server - Virtual Sound Card:

I gave up on that linux VM so can't test it but I tried many things under the sun involving ALSA and PulseAudio, I had a real Linux brain box helping me out with it and neither of us could get it working after a week of trying different things out.

So that's not urgent at all. You made me curious, so maybe I'll take a look into it during the next few days

Oh it was urgent 3 months ago

The fix was to bite the bullet and pay triple the cost for a Windows VM to do it.

thwr

Hehe. Is Ubuntu Server 16.04 ok for you?

Deleted74295

@thwr said in Ubuntu Server - Virtual Sound Card:

Hehe. Is Ubuntu Server 16.04 ok for you?

Sure, whenever really, no rush.

chrisnbrooks

@thwr said in Ubuntu Server - Virtual Sound Card:
...

https://ubuntuforums.org/showthread.php?t=2119648

Good read! Wish I still had my blade in Chicago so I could test this out just for gits and shiggles.
Maybe finally time to renew that contract ... this time sans hosting clients.

thwr

@chrisnbrooks said in Ubuntu Server - Virtual Sound Card:

@thwr said in Ubuntu Server - Virtual Sound Card:
...

https://ubuntuforums.org/showthread.php?t=2119648

Good read! Wish I still had my blade in Chicago so I could test this out just for gits and shiggles.
Maybe finally time to renew that contract ... this time sans hosting clients.

Just create a VM with no sound hardware

chrisnbrooks

@thwr said in Ubuntu Server - Virtual Sound Card:

@chrisnbrooks said in Ubuntu Server - Virtual Sound Card:

@thwr said in Ubuntu Server - Virtual Sound Card:
...
Maybe finally time to renew that contract ... this time sans hosting clients.

Just create a VM with no sound hardware

Hah! Nooo... Just take my money!!!

thwr

Ok, got it. It's actually pretty simple. Tried this in a fresh new Ubuntu 16.04.1 VM on VirtualBox. The VM does not have sound hardware (disabled in VirtualBox).
I had some problems with the recorded file, there was just white noise. Turned out something went wrong when I tried to record the output using arecord and pipe that to lame to get a MP3. Switched to WAV instead.

Preparations:

sudo modprobe snd-aloop
sudo apt-get install alsa

Check devices:

tw@ubuntu-snddummy:~$ sudo aplay -l
**** List of PLAYBACK Hardware Devices ****
Home directory not accessible: Permission denied
card 0: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 7/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 0: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
tw@ubuntu-snddummy:~$

Play something

sudo aplay -D hw:0,0,0 sample.wav
Playing WAVE 'sample.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

Record (different shell)

sudo arecord -D hw:0,1,0 -f cd record.wav

PS: Did everything as root to avoid any permission issues.

Source:
http://www.alsa-project.org/main/index.php/Matrix:Module-aloop

Deleted74295

Nice work, really good find.

Will remember to try this in the future.

thwr

Thanks, I was just curious Please report back if that works for you.

scottalanmiller

This got way more popular than I had been expecting it to be!

thwr

@scottalanmiller said in Ubuntu Server - Virtual Sound Card:

This got way more popular than I had been expecting it to be!

Now we just need to find use-cases for this

scottalanmiller

@thwr said in Ubuntu Server - Virtual Sound Card:

@scottalanmiller said in Ubuntu Server - Virtual Sound Card:

This got way more popular than I had been expecting it to be!

Now we just need to find use-cases for this

That's the bigger challenge

travisdh1

@thwr said in Ubuntu Server - Virtual Sound Card:

@scottalanmiller said in Ubuntu Server - Virtual Sound Card:

This got way more popular than I had been expecting it to be!

Now we just need to find use-cases for this

Back in the late 90s, a group of ~50 engineers and FEA people would have loved to have that available. We could do 3D remotely, but sound without an audio card, not so much.