bluealsa-handsfree-audio.bash.in

#!/bin/bash

# bluealsa simple handsfree version @version@
# HFP/HSP audio stream routing

# Default ALSA speaker, microphone, and latency
# override by defining in environment
BA_HF_SPEAKER="${BA_HF_SPEAKER:-default}"
BA_HF_MICROPHONE="${BA_HF_MICROPHONE:-default}"
BA_HF_LATENCY="${BA_HF_LATENCY:-100}"
BA_HF_SOFTVOL="${BA_HF_SOFTVOL:-true}"

declare -A device=( [path]="" [codec]="" [profile]="" [sink]="" [source]="" )
declare -A audio
declare -A sink
declare -A source
declare -A monitor=( [fifo]= [pid]= )
declare -A alsa=(
	[spk]="$BA_HF_SPEAKER"
	[mic]="$BA_HF_MICROPHONE"
)
declare use_softvol="true"
[[ "${BA_HF_SOFTVOL,,}" =~ (false|no|off|0) ]] && use_softvol="false"
[[ "${BA_HF_SOFTVOL,,}" == "hsp" ]] && use_softvol="hsp"

reset_sink() {
	sink=(
		[running]=
		[pid]=
	)
}

reset_source() {
	source=(
		[running]=
		[pid]=
	)
}

reset_state() {
	audio=()
	reset_sink
	reset_source
}

init_alsa_properties() {
	BA_HF_LATENCY=$(( (BA_HF_LATENCY + 10)/ 20 * 20 ))
	(( BA_HF_LATENCY >= 20 )) || BA_HF_LATENCY=20
	alsa[threshold]="$(( BA_HF_LATENCY * 1000 ))"
	alsa[period]=$(( alsa[threshold] / 2 ))
	alsa[buffer]=$(( alsa[period] * 4 ))

cat <<-EOF >&2
	ALSA CONFIG:
	period: ${alsa[period]}us, buffer: ${alsa[buffer]}us, latency: ${alsa[threshold]}us
	Speaker: ${alsa[spk]}
	Microphone: ${alsa[mic]}
EOF
}

# @param $1 codec
set_codec() {
	local codec="${1,,}"
	case "$codec" in
		cvsd)
			audio[format]=s16_le
			audio[channels]=1
			audio[rate]=8000
			device[codec]="$codec"
			;;
		msbc)
			audio[format]=s16_le
			audio[channels]=1
			audio[rate]=16000
			device[codec]="$codec"
			;;
	esac
}

start_monitor() {
	local fd path=$(mktemp -u)
	mkfifo $path
	exec {fd}<>$path
	rm $path
	bluealsa-cli --quiet --verbose monitor --properties=Codec,Running >&$fd &
	monitor[pid]=$!
	monitor[fifo]=$fd
}

stop_monitor() {
	[[ "${monitor[pid]}" ]] && kill ${monitor[pid]}
	[[ "${monitor[fifo]}" ]] && exec {monitor[fifo]}>&-
	monitor=()
}

start_source() {
	[[ "${device[source]}" ]] || return
	bluealsa-cli open "${device[path]}source" > >(aplay -q -t raw -f "${audio[format]}" -c 1 -r "${audio[rate]}" -D "${alsa[spk]}" -F "${alsa[period]}" -B "${alsa[buffer]}" -R "${alsa[threshold]}") &
	source[pid]=$!
}

stop_source() {
	[[ "${source[pid]}" ]] && kill -TERM "${source[pid]}"
	source[pid]=
}

start_sink() {
	[[ "${device[sink]}" ]] || return
	[[ "${alsa[mic],,}" = none ]] && return
	arecord -q -t raw -f "${audio[format]}" -c 1 -r "${audio[rate]}" -F "${alsa[period]}" -B "${alsa[buffer]}" -R "${alsa[threshold]}" -D ${alsa[mic]} | bluealsa-cli open "${device[path]}sink" &
	sink[pid]=$!
}

stop_sink() {
	[[ "${sink[pid]}" ]] && kill -TERM "${sink[pid]}"
	sink[pid]=
}

start_audio() {
	start_sink
	start_source
}

stop_audio() {
	stop_sink
	stop_source
}

cleanup() {
	stop_audio
	stop_monitor
	kill -- -$$
}

# @param $1 device path
get_device_codec() {
	local REPLY
	while read -r ; do
		case "$REPLY" in
			"Selected codec:"*)
				set_codec "${REPLY#*: }"
			;;
		esac
	done <<<$(bluealsa-cli info "$1")
}

apply_softvol_setting() {
	local setting="true"
	[[ "$use_softvol" == "hsp" && ${device[profile]} == "hfp" ]] && setting="false"
	[[ "$use_softvol" == "false" ]] && setting="false"
	bluealsa-cli soft-volume "${device[path]}source" "$setting"
}

trap 'trap "" EXIT INT TERM; cleanup 2>/dev/null; exit' EXIT INT TERM

reset_state
init_alsa_properties
start_monitor

stream=
properties=

while read -u ${monitor[fifo]} ; do
	case "$REPLY" in
		ServiceStopped*)
			[[ "${sink[running]}" ]] && stop_sink
			[[ "${source[running]}" ]] && stop_source
			reset_state
			continue
			;;
		*": "*)
			[[ "$stream" && "$properties" ]] || continue
			property_name="${REPLY%%:*}"
			property_value="${REPLY##*: }"
			case "$property_name" in
				"Selected codec")
					set_codec "${property_value}"
					;;
			esac
			continue
			;;
		"")
			properties=
			stream=""
			continue
			;;
	esac

	reply=( $REPLY )
	path="${reply[1]}"
	if [[ "$path" == */hfphf/* ]] ; then
		device[profile]="hfp"
	elif [[ "$path" == */hsphs/* ]] ; then
		device[profile]="hsp"
	else
		continue
	fi

	stream="${path##*/}"
	dev_path="${path%$stream}"
	if [[ "${device[path]}" && "${device[path]}" != "$dev_path" ]] ; then
		stream=""
		continue
	fi

	case "${reply[0]}" in
		PCMAdded)
			device[path]="$dev_path"
			device[$stream]=1
			properties=1
			apply_softvol_setting
			;;
		PCMRemoved)
			stop_audio
			reset_state
			device[path]=""
			device[$stream]=""
			stream=""
			properties=""
			;;
		PropertyChanged)
			property_name="${reply[2]}"
			property_value="${reply[3]}"
			if [[ -z "${device[path]}" ]] ; then
				device[path]="$dev_path"
				device["$stream"]=1
				get_device_codec "$path"
				apply_softvol_setting
			fi
			case "$property_name" in
				Codec)
					set_codec "${property_value}"
					;;
				Running)
					declare -n pcm=$stream
					if [[ "$property_value" = "false" ]] ; then
						stop_$stream
						pcm[running]=
					else
						pcm[running]=1
						if [[ "${sink[running]}" && "${source[running]}" ]] ; then
							start_audio
						fi
					fi
					;;
			esac
			;;
	esac
done