Directs audio in from Bluetooth device to all audio outputs on connect.

bluez-udev-audio.sh

#!/bin/bash
#This script was written for raspberry-pi-audio-reciever
#Project and can be found in it's original form at: 
#https://github.com/BaReinhard/Super-Simple-Raspberry-Pi-Audio-Receiver-Install/blob/master/usr/local/bin/bluez-udev
#My version of this script directs audio input from a 
#bluetooth device to all availabe audio outputs (aka sinks)

audio_sink=0
name=$(sed 's/\"//g' <<< $NAME)
#exit if not a BT address
if [[ ! $name =~ ^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})$ ]]; then exit 0;  fi

bt_name=`grep Name /var/lib/bluetooth/*/$name/info | awk -F'=' '{print $2}'`

audio_source=bluez_source.$(sed 's/:/_/g' <<< $name)

action=$(expr "$ACTION" : "\([a-zA-Z]\+\).*")
logger "Action: $action"
if [ "$action" = "add" ]; then
    audio_sinks=$(pactl list sinks short |cut -f 1)
    for audio_sink in $audio_sinks; do
        logger "[$(basename $0)] Bluetooth device is being added [$name] - $bt_name"
        logger "[$(basename $0)] Patching $audio_source into ALSA sink #$audio_sink"
        #hciconfig hci0 noscan
        bluetoothctl << EOT
discoverable off
EOT
        amixer cset numid=3 1
        amixer set PCM 90%
        #espeak -s 160 -k 1 "Device, $bt_name Connected"
        /usr/local/bin/say.sh "Device, $bt_name Connected"
        amixer set PCM 100%
        sleep 1
        pactl set-sink-volume 0 65537

        # loop back this source to the default sink
        ID=$(pactl load-module module-loopback source=$audio_source sink=$audio_sink)
        logger "[$(basename $0)] PulseAudio module-loopback returned handle [$handle]"
        logger "$bt_name"
    done
fi

if [ "$action" = "remove" ]; then
    logger "[$(basename $0)] Bluetooth device is being removed [$name] - $bt_name"
    #hciconfig hci0 pscan

    bluetoothctl << EOT
discoverable on
EOT

    # remove any loopback modules assigned to this source
    # only required for USB sound cards, which PulseAudio will not automatically remove
    for ID in $(pactl list short modules | grep module-loopback | grep source=$audio_source | cut -f 1); do
        logger "[$(basename $0)] Unloading module-loopback with handle [$ID]"
        pactl unload-module $ID
    done
    sleep 5
    amixer set PCM 90%
    #espeak -s 160 -k 1 "Device, $bt_name Disconnected"
    /usr/local/bin/say.sh "Device, $bt_name Disconnected"
    amixer set PCM 100%
fi

# prevents any feedback loops caused by multiple module-loopbacks to sink(s)

audio_sinks=$(pactl listt sinks short |cut -f 1)

for audio_sink in $audio_sinks; do

    while [[ $(pactl list modules short |grep module-loopback |grep source=bluez |grep sink=$audio_sink |cut -f 1| wc -l) -gt 1 ]]; do

        EXCESS_MODULE="$(pactl list modules short |grep module-loopback |grep source=$audio_source |grep sink=$audio_sink |cut -f 1 |tail -n +2 |tail -n1)"

        logger "[$(basename $0)] Multiple source to sink detected unloading module-loopback with handle [$EXCESS_MODULE]"

        pactl unload-module $EXCESS_MODULE

    done

done