combine_streams.sh

#!/bin/bash

# this small scrip combine audio streams from a running instance of pulseaudio
# and creates a new virtual input

f_log() {
   echo "[+] $0 -> $*"
}

function usage () {
cat << EOF
You need to call this script like this : $0 (-r) -i <input>
  -r : reset pulseaudio to default and so removes virtual input
EOF
}

while getopts "hri:" option
do
  case ${option} in
    h)
      usage
      exit
      ;;
    r)
     action=reset
      ;;
    i)
     amplifier_model=${OPTARG}
     ;;
    ?)
      usage
      exit
      ;;
  esac
done

# Checking first if we just need to reset pulseaudio
if [ "${action}" == "reset" ] ; then
   f_log "Resetting pulseaudio to defaults ..."
   pactl unload-module module-loopback
   pactl unload-module module-null-sink
   sleep 2
   pulseaudio -k
   exit
fi

# Parsing amplifier input to combine and exit if not specified
# One can use the following commands to know which sources are available
# pacmd list-sources | egrep '(^\s+name: .*)|(^\s+device.description = .*)'

f_log "Soundcore Life Q30"
source_device="alsa_input.usb-046d_BRIO_4K_Stream_Edition_1DB4692C-02.analog-stereo"
sink_name="monitor-soundCore"
fake_input_name="SoundCore-And-Mic"

# Now let's do the real work
# Common
monitor_device="bluez_sink.AC_12_2F_50_D9_56.a2dp_sink.monitor"

f_log "Adding new sink [${sink_name}]"
pactl load-module \
    module-null-sink sink_name=${sink_name} \
    sink_properties=device.description=Source-monitor-amp

sleep 5
f_log "Adding monitor device [${monitor_device}] to created sink [${sink_name}]"
pactl load-module \
    module-loopback source=${monitor_device} \
    sink_dont_move=true sink=${sink_name}

sleep 5
f_log "Adding external amplifier [${source_device}] to created sink [${sink_name}]"
pactl load-module \
    module-loopback source=${source_device} \
    sink_dont_move=true sink=${sink_name}

sleep 5
# Create fake input combining all sinks
f_log "Creating new virtual input [${fake_input_name}] to be used as input for recording"
pactl load-module \
    module-remap-source source_name=${fake_input_name} \
    master=${sink_name}.monitor \
    source_properties=device.description=${fake_input_name}