Play audio files on your microphone with ffmpeg

README.md

play-audio-mic.sh

This script was adapted to allow you to play audio files through your microphone input. It does so by creating a virtual microphone and piping an audio file to it.

The work was mostly done in this StackOverflow answer, I just adapted it to use ffmpeg and add a trap to cleanup on exit.

Requirements:

• ffmpeg
• Bash
• PulseAudio/pactl

play-audio-mic.sh

#!/bin/bash

# This script will create a virtual microphone for PulseAudio to use and set it as the default device.
# Adapted from: https://stackoverflow.com/a/43553706/2272346

INPUT_FILE=$1
VIRTMIC_PATH=/tmp/virtmic

function cleanup() {
  pactl unload-module module-pipe-source
  rm -f "$HOME"/.config/pulse/client.conf
}

# 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=$VIRTMIC_PATH format=s16le rate=16000 channels=1

trap cleanup EXIT

# 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"/.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."

ffmpeg -re -i "$INPUT_FILE" -f s16le -ar 16000 -ac 1 - > "$VIRTMIC_PATH"

cleanup