Hello, Thank you for your answer. At the end, I decided to create my null-sink in /etc/pulse/default.pa : load-module module-null-sink sink_name=MySink load-module module-alsa-source device=hw:1,0 source_name=MySoundcard1 Later in my program I make the loopback : $ pacmd load-module module-loopback source=MySoundcard1 sink=MySink Then, I can use gstreamer with : pulsesrc device=MySink.monitor ... To read the audio stream. ++ Jack Le mercredi 16 février 2022 à 00:23 -0800, Sean Greenslade a écrit : > On Sun, Feb 13, 2022 at 09:49:30PM +0100, corbeille wrote: > > Hello, > > > > I would like to know if there is a possibility to create at startup > > (maybe in /etc/pulse/default.pa ?) a "connection" between Alsa > > input hw:1,0 and a null-sink thru a loopback ? > > To have something similar to : > > > > $ pacmd load-module module-null-sink sink_name=MySink > > $ pacmd load-module module-loopback source=hw:1,0 sink=MySink > > > > Instead of : > > > > $ pacmd load-module module-null-sink sink_name=MySink > > $ pacmd load-module module-loopback source=alsa_input.usb-0d8c_C- > > Media_USB_Headphone_Set-00.mono-fallback sink=MySink > > > > Thus, I will be able to link "MySink" with any sound card on > > hw:1,0. > > > > Is it possible ? > > I don't think it's possible with the normal pulseaudio setup, since > the > alsa cards are added after everything in default.pa is processed. The > module-udev-detect module dynamically loads and unloads alsa cards as > they are sensed by the hardware. It's a limitation of the > module-loopback code that the requested source/sink must exist at > loading time. > > One thing you could do if your machine only has one sound card on a > non-removable connection (i.e. not a USB device) is to statically > define > it with module-alsa-card and disable module-udev-detect. > > A more resilient option might be to make a script that checks for the > presence of the loopback and loads it if it's not present. Then just > fire that script unconditionally before launching your programs that > use > it. > > --Sean >
