How to Redirect from Audio Output to Mic Input Using Pulseaudio

How to redirect from Audio Output to Mic Input using PulseAudio?

The manuals for pactl and pacmd are readily available if you give it a search. I found them here:

pactl

pacmd (pulse-cli-syntax)

I think you are interested in the following excerpt from the pactl manual:

move-sink-input ID SINK :
Move the specified playback stream (identified by its numerical index) to the specified sink (identified by its symbolic name or numerical index).

You should be able to use pactl list sink-inputs, pactl list source-outputs, pactl list sinks, and pactl list sources combined with some grep and/or sed or something of that nature to programmatically determine the correct stream and sink.

Linux pipe audio file to microphone input

After many painstaking hours, I finally got something acceptable working. I undid everything I did with ALSA (since the default is for ALSA to use PulseAudio instead, which I initially overrode). I created a simple bash script install_virtmic.sh to create a "virtual microphone" for PulseAudio to use as well as PulseAudio clients:

#!/bin/bash

# This script will create a virtual microphone for PulseAudio to use and set it as the default device.

# Load the "module-pipe-source" module to read audio data from a FIFO special file.
echo "Creating virtual microphone."
pactl load-module module-pipe-source source_name=virtmic file=/home/charles/audioFiles/virtmic format=s16le rate=16000 channels=1

# Set the virtmic as the default source device.
echo "Set the virtual microphone as the default device."
pactl set-default-source virtmic

# Create a file that will set the default source device to virtmic for all 
PulseAudio client applications.
echo "default-source = virtmic" > /home/charles/.config/pulse/client.conf

# Write the audio file to the named pipe virtmic. This will block until the named pipe is read.
echo "Writing audio file to virtual microphone."
while true; do
    cat audioFile0.raw > /home/charles/audioFiles/virtmic
done

A quick script uninstall_virtmic.sh for undoing everything done by the install script:

#!/bin/bash

# Uninstall the virtual microphone.

pactl unload-module module-pipe-source
rm /home/charles/.config/pulse/client.conf

I then fired up Chromium and clicked the microphone to use its voice search feature and it worked! I also tried with arecord test.raw -t raw -f S16_LE -c 1 -r 16000 and it worked too! It isn't perfect, because I keep writing to the named pipe virtmic in an infinite loop in the script (which quickly made my test.raw file insanely large), but it will do for now.

Please feel free to let me know if anyone out there finds a better solution!

Pulseaudio - combined mic streams to play output on combined speaker sink

This did what I wanted:

pactl load-module module-loopback latency_msec=1 source=alsa_input.pci-0000_00_1b.0.analog-stereo sink=bluez_sink.00_02_5B_00_FF_03

pactl load-module module-loopback latency_msec=1 source=bluez_source.00_02_5B_00_FF_03 sink=alsa_output.pci-0000_00_1b.0.analog-stereo

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