Records audio from live output
Aus Wiki
1) find monitor device:
$ pacmd list | grep "\.monitor"
name: <alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor>
name: <alsa_output.pci-0000_00_1b.0.analog-stereo.monitor>
alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor/#0: Monitor of HDA NVidia Digital Stereo (HDMI)
alsa_output.pci-0000_00_1b.0.analog-stereo.monitor/#2: Monitor of Built-in Audio Analog Stereo
2) Capture audio to file:
$ pacat --record -d alsa_output.pci-0000_00_1b.0.analog-stereo.monitor > dump.raw
3) Convert file to wav:
sox -t raw -r 44100 -e signed-integer -L -b 16 -c 2 dump.raw output.wav