How to record audio from only a specific program on linux?

Question

Is there a way to record the audio from only a specific program, so that other sounds (e.g. notifications) are not recorded?

I'm running Archlinux with pulseaudio.

Answer 1

You can use pacat which is part of pulseaudio.

First open your application. THen run pactl list and find your device. in my example, I will use chrome

snipet:

Client #229
Driver: protocol-native.c
    Owner Module: 8
    Properties:
        application.name = "Chrome input"
    native-protocol.peer = "UNIX socket client"
        native-protocol.version = "28"
    application.process.id = "16404"
        application.process.user = "robert"
        application.process.host = "HS"
        application.process.binary = "chrome"
        application.language = "en_US.UTF-8"
    window.x11.display = ":0.0"
        application.process.machine_id = "15d4d55cf80e320acb892977520d0894"
        application.process.session_id = "c1"

I'll grab the application name and run pacat.

 pacat -r -n "Chrome input" | sox -t raw -r 44100 -s -L -b 16 -c 2 - "output.wav"

You can also use pacat to capture from a device, etc. the pacat man page has some more info