Windows – How to record audio from the microphone with ffmpeg

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

A little late, but if anyone had the same question, you have to use the trim "effect" to record a set length of audio.

So to record 10 seconds of audio just append trim 0 10 at the end of your command, e.g.,

$ sox -b 32 -e unsigned-integer -r 96k -c 2 -d --clobber --buffer $((96000*2*10)) /tmp/soxrecording.wav trim 0 10

From the SoX man:

trim {position(+)}

Cuts portions out of the audio. Any number of positions may be given; audio is not sent to the output until the first position is reached. The effect then alternates between copying and discarding audio at each position. Using a value of 0 for the first position parameter allows copying from the beginning of the audio.