はじめに
ラズパイ上でインターネットラジオを作成した経験をもとに、使用したコマンド (ALSA、Bluetooth、Unix) をまとめました。
ALSA（Advanced Linux Sound Architecture）
出力
aplay /usr/share/sounds/alsa/Front_Center.wav
aplay -v /usr/share/sounds/alsa/Front_Center.wav
aplay -D plughw:1,0 /usr/share/sounds/alsa/Front_Left.wav
aplay -D hw:1,0 /usr/share/sounds/alsa/Front_Center.wav
Bluetooth出力
aplay -D bluealsa:HCI=hci0,DEV=6C:56:97:90:15:1F,PROFILE=a2dp /usr/share/sounds/alsa/Front_Center.wav
aplay -D bluealsa /usr/share/sounds/alsa/Front_Center.wav
リスト
aplay -l (List all soundcards and digital audio devices)
aplay -L (List all PCMs defined)
サウンドloopBack
sudo modprobe -r --first-time snd-aloop || true
aplay -l
sudo modprobe snd-aloop pcm_substreams=2
aplay -l
sudo -u pi alsaloop -C dsnooped -P plughw:1,0 -c 1 -t 500000 &
sudo -u pi alsaloop -C dsnooped -P bluealsa -c 1 -t 500000 &
sudo -u pi alsaloop -C dsnooped -P bluealsa:HCI=hci0,DEV=C9:72:03:77:06:71,PROFILE=a2dp -c 1 -t 500000 &
sudo -u pi alsaloop -C dsnooped -P bluealsa -c 1 -t 50000 （MicroSecond、underrun for playback bluealsa）
alsaloop -C hubcap -P hw:0 -v -v -U (デバッグ)
Bluetooth
ペアリング、接続、状況確認
$ sudo /usr/bin/bluetoothctl
info
show
scan on/off
pair
trust
connect
remove
デバイス確認
$ amixer -D bluealsa
Simple mixer control 'Echo Dot-BF4 - A2DP',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 127
Mono:
Front Left: Playback 127 [100%] [on]
Front Right: Playback 127 [100%] [on]
再起動 sudo service bluetooth restart
vlc /usr/bin/cvlc --aout=alsa --alsa-audio-device=bluealsa
PulseAudio の自動起動を中止する
/etc/pulse/client.conf を１行修正する
autospawn = no
インストール
sudo apt-get install bluez pulseaudio-module-bluetooth python-gobject python-gobject-2
sudo apt install bluealsa
Unix
プロセス監視、kill
top
ps -ef | grep alsaloop | grep -v grep | awk '{ print $2}'
ps -ef | grep alsaloop | grep -v grep | awk '{ print $2}' | sudo xargs --no-run-if-empty kill -9
ps -ef | grep -E "pulse|vlc|node|loop|alsa|startx|X|light|crom|python"
CPU、Memory、Net、Paging、Dsk、Interrupts監視
dstat -cmngdi
Log監視
tail -f /var/log/syslog
dmesg -T --follow
サーバ起動
sudo -u pi /usr/bin/tightvncserver &
export HOME=/root ; startx
sudo service lightdm stop/start
sudo -u pi /usr/bin/node-red &
ロガー
logger msg
| logger
その他
sleep 1
sudo -u pi
particular_script || true
set -o pipefail
参考URL
https://www.alsa-project.org/wiki/Asoundrc
https://wiki.archlinux.org/index.php/Advanced_Linux_Sound_Architecture
Raspberry PiでBluetoothスピーカーを鳴らす
https://qiita.com/homelan/items/e82b919638d3c458d2ec
Bluez5/bluez-alsa
https://wiki.archlinux.jp/index.php/Bluetooth_%E3%83%98%E3%83%83%E3%83%89%E3%82%BB%E3%83%83%E3%83%88#Bluez5.2Fbluez-alsa
Raspberry Pi で Bluetooth レシーバー (オーディオ:A2DP) を作成するための設定方法解説
https://qiita.com/dwarfJP/items/a4a90d5c0aa2833dac5b
Bluetooth audio streaming
https://www.raspberrypi.org/forums/viewtopic.php?t=68779
Raspberry Pi をA2DPのsinkにして携帯やタブレットから音楽を再生する
http://d.hatena.ne.jp/penkoba/20130909/1378744109
付録
設定ファイル
defaults.bluealsa {
interface "hci0"
device "6C:56:97:90:15:1F"
profile "a2dp"
delay 500000
channels 2
}
# dsnooped input
# dsnooped allows multiple applications to use an input device (microphone)
# without dsnoop, devices are exclusive, and the mic can only be used by one app at a time.
pcm.dsnooped {
type dsnoop
ipc_key 5978293 # must be unique for all dmix plugins!!!!
ipc_key_add_uid yes
slave {
pcm {
format S16_LE
rate 48000
nonblock true
type hw
card Loopback
device 1
subdevice 0
}
channels 2
period_size 1024
buffer_size 8192
periods 0
period_time 0
}
}
pcm.dmixed {
type dmix
ipc_key_add_uid true
ipc_key 5678293
ipc_perm 0660
ipc_gid audio
slave {
channels 2
pcm {
format S16_LE
rate 48000
nonblock true
type hw
card Loopback
device 0
subdevice 0
}
period_size 1024
buffer_size 8192
}
}
# this 'combines' both input and optput devices into a single pseudo-device
pcm.asymd {
type asym
playback.pcm "dmixed"
capture.pcm "dsnooped"
}
# this sets the above combined device as the default input/output
pcm.!default {
type plug
slave.pcm "asymd"
}