ALSA - JACK loopback approach

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ttshaw1
Posts: 1
Joined: Tue Jul 13, 2021 2:25 am

ALSA - JACK loopback approach

Post by ttshaw1 »

I'm trying the "robust" approach mentioned here (https://jackaudio.org/faq/routing_alsa.html) and detailed here (https://alsa.opensrc.org/Jack_and_Loopb ... ridge#id02)
to getting ALSA to work at the same time as JACK. The idea is to activate the snd-aloop kernel module to create a virtual soundcard, where any sound input to the card (application playing audio) is available as an output (virtual mic input). Then I use JACK to route that virtual microphone to my system playback.

What I've done so far

1.

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sudo modprobe snd-aloop
to enable the loopback kernel module. Verified it's running with

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aplay -l
2. Copy the generic .asoundrc file from the "asoundrc definition" section to /home/$USER/.asoundrc, as well as to /etc/asound.conf
3. Restart
4.

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sudo modprobe snd-aloop
again
4. Switch output device in the Linux mint audio GUI from the loopback device to the default line out device. Verify audio is working with

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aplay -D default test.wav
5. Start qjackctl and start JACK
6. Manually enter the commands in "Create scripts to automate bridge initialization via QjackCtl" BUT substitute playback_3 and playback_4 for 1 and 2 (necessary on my computer)


I can see the loopback devices in JACK and the connections are as expected from the commands, yet I get no audio from ALSA programs. For example,

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aplay -D default test.wav
outputs nothing.

Could it be that I need to change something else due to my changing the playback devices in step 6? What else can I do to troubleshoot why cloop seems to not be outputting anything? Thanks!
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