# linux jack audio config

## linux audio

`ALSA` is kernel module 必選

{jack, pulseaudio, pipewire} 是 usermode audio server, 三選一。又因為 jack realtime 最好，可以優先使用。

alsa-->jack-->mpd 這個打通了

but, since ubuntu expect pipewire, alsa(remained audio card)-->pipewire-->system desktop app 被強制用hdmi。

由於pipewire 移除可能會問題，所以最佳解是。

1. 讓 jack 管理盡量多的 audio 介面
1. 讓 pipewire 做為jack 的 二級server，而非直接和alsa 對接（只有jack 可以）。

Wireplumber 是什麼？
> WirePlumber is a powerful session and policy manager for PipeWire

簡單說就是要一起才能工作。

ideal 的 情況是

alsa --> jack --> pipewire --> wireplumber --> gnome-control-center

### jack config

jackd 啟動時只能選一個 device。然後用 alsa_in, alsa_out 去加入其他device。

jack2 == jackdmp == jackd

`aplay -l`

#/etc/systemd/system/jack.service

[Unit]
Description=JACK Audio Connection Kit
Documentation=man:jackd(1)
After=sound.target local-fs.target
StartLimitIntervalSec=3
StartLimitBurst=5

[Service]
Type=notify
#EnvironmentFile=-/etc/jack/%i.conf
#EnvironmentFile=-%h/.config/jack/%i.conf
User=morgana
Environment="JACK_NO_AUDIO_RESERVATION=1"
ExecStart=/usr/bin/jackd -P95 -dalsa -dhw:2,0 -r44100 -n3 -p512
#ExecStart=@PREFIX@/bin/jackd $JACK_OPTIONS -d $DRIVER -d $DEVICE $DRIVER_SETTINGS
ExecStartPost=/usr/local/bin/add-jack-devices.sh
Restart=on-failure
LimitRTPRIO=95
LimitRTTIME=infinity
LimitMEMLOCK=infinity

[Install]
WantedBy=multi-user.target

#!/bin/bash
# filepath: /usr/local/bin/add-jack-devices.sh

# Add HDMI 1 from card 0 (HDA NVidia)
#alsa_in -j "HDMI_1_Nvidia" -d hw:0,7 &
alsa_out -j "HDMI_1_Nvidia" -d hw:0,7 &

# Add HDMI 1 (ASUS VZ27V) from card 1 (HD-Audio Generic)
#alsa_in -j "HDMI_1_ASUS" -d hw:1,7 &
alsa_out -j "HDMI_1_ASUS" -d hw:1,7 &

# Add ALC897 Analog from card 2 (HD-Audio Generic)
#already add
#alsa_in -j "ALC897_Analog" -d hw:2,0 &
#alsa_out -j "ALC897_Analog" -d hw:2,0 &

exit 0

### pipewire config

[pipewire.conf](https://docs.pipewire.org/page_man_pipewire_conf_5.html#pipewire_conf__drop-in_configuration_files)

#/home/morgana/.config/pipewire/pipewire.conf.d/custom.conf

context.properties = {
    default.clock.rate          = 48000
    default.clock.allowed-rates = [ 48000 ]
    default.clock.quantum       = 1024
    default.clock.min-quantum   = 128
    default.clock.max-quantum   = 2048
}

context.modules = [
    { name = libpipewire-module-jack-tunnel }
    { name = libpipewire-module-jackdbus-detect }
]

# /home/morgana/.config/pipewire/jack.conf.d/custom.conf
                                         
jack.properties = {
    rt.prio             = 88
    node.latency        = 1024/48000
    node.lock-quantum   = true
    jack.show-monitor   = true
    jack.merge-monitor  = true
    jack.show-midi      = true
    jack.short-name     = false
    jack.self-connect-mode = allow
    jack.default-as-system  = true
}

[jack.conf](https://docs.pipewire.org/page_man_pipewire-jack_conf_5.html)

就能 設定 pipewire

`pw-cli`(Interact with a PipeWire instance.)

if you need restart
`systemctl --user restart pipewire` may work

### wireplumber

最後是 wirePlumber(一般 pipewire 對就ok)

`wpctl status`

> `systemctl --user status xdg-desktop-portal`
> `systemctl --user status wireplumber`

最後其實要確定是否對接到 `gnome-control-center`

要注意 `pulseaudio` 和 `pipewire-pulse` 會 二選一 自動 install。所以不要 uninstall `pipewire-pulse`

## mpd

> 可能改成 系統當 output，在 系統控管下會更好

# ~/.config/mpd/mpd.conf

music_directory		"~/Music/mpd"
playlist_directory	"~/.config/mpd/playlists"
db_file			"~/.config/mpd/database"
# Uncomment to enable the functionalities
#playlist_directory "~/.config/mpd/playlists"
#pid_file           "~/.config/mpd/pid"
#state_file         "~/.config/mpd/state"
#sticker_file       "~/.config/mpd/sticker.sql"

#user				"mpd"
#group                          "audio"

bind_to_address			"0.0.0.0"
auto_update	"yes"
follow_outside_symlinks	"yes"
follow_inside_symlinks		"yes"
zeroconf_enabled		"yes"
zeroconf_name			"Music Player @ %h"



input {
        plugin "curl"
}



decoder {
        plugin                  "hybrid_dsd"
        enabled                 "no"
}
decoder {
        plugin        "wildmidi"
        enabled       "no"
}


# mpd with jack in root priviledge is buggy. use it with user mode.
#[mpc can't control volume?](https://forums.raspberrypi.com/viewtopic.php?t=150505)
audio_output {
        type            "jack"
        name            "jack output"
        client_name     "mpd"
        mixer_type      "software"
}

# An example of an ALSA output:
# minor bug: mixer: Failed to read mixer for 'My ALSA Device': no such mixer control: PCM
# still work.
# make sure jack doens't start.
# audio_output {
# 	type		"alsa"
# 	name		"My ALSA Device"
# #	device		"hw:0,0"	# optional
# 	device		"hw:CARD=sofhdadsp,DEV=0"	#this will work
# #	mixer_type      "hardware"	# optional
# #	mixer_device	"default"	# optional
# #	mixer_control	"PCM"		# optional
# #	mixer_index	"0"		# optional
# }



filesystem_charset		"UTF-8"

`systemctl --user status mpd.service`

* [Problem starting JACK server "Jack Server is not running or cannot be started"](https://askubuntu.com/questions/557906/problem-starting-jack-server-jack-server-is-not-running-or-cannot-be-started)