;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2023 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2023 Brian Cully <bjc@spork.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu home services sound)
#:use-module (gnu home services)
#:use-module (gnu home services shepherd)
#:use-module (gnu home services xdg)
#:use-module (gnu packages linux)
#:use-module (gnu services configuration)
#:use-module (guix records)
#:use-module (guix gexp)
#:use-module (srfi srfi-1)
#:use-module (ice-9 match)
#:export (home-pulseaudio-rtp-sink-service-type
home-pulseaudio-rtp-source-service-type
%pulseaudio-rtp-multicast-address
home-pipewire-configuration
home-pipewire-service-type))
;;;
;;; PipeWire support.
;;;
(define-configuration/no-serialization home-pipewire-configuration
(pipewire
(file-like pipewire)
"The PipeWire package to use.")
(wireplumber
(file-like wireplumber)
"The WirePlumber package to use.")
(enable-pulseaudio?
(boolean #t)
"When true, enable PipeWire's PulseAudio emulation support, allowing
PulseAudio clients to use PipeWire transparently."))
(define (home-pipewire-shepherd-service config)
(shepherd-service
(documentation "PipeWire media processing.")
(provision '(pipewire))
(requirement '(dbus))
(start #~(make-forkexec-constructor
(list #$(file-append
(home-pipewire-configuration-pipewire config)
"/bin/pipewire"))))
(stop #~(make-kill-destructor))))
(define (home-pipewire-pulseaudio-shepherd-service config)
(shepherd-service
(documentation "Drop-in PulseAudio replacement service for PipeWire.")
(provision '(pipewire-pulseaudio))
(requirement '(pipewire))
(start #~(make-forkexec-constructor
(list #$(file-append
(home-pipewire-configuration-pipewire config)
"/bin/pipewire-pulse"))))
(stop #~(make-kill-destructor))))
(define (home-wireplumber-shepherd-service config)
(shepherd-service
(documentation "WirePlumber session management for PipeWire.")
(provision '(wireplumber))
(requirement '(pipewire))
(start #~(make-forkexec-constructor
(list #$(file-append
(home-pipewire-configuration-wireplumber config)
"/bin/wireplumber"))))
(stop #~(make-kill-destructor))))
(define (home-pipewire-shepherd-services config)
(cons* (home-pipewire-shepherd-service config)
(home-wireplumber-shepherd-service config)
(if (home-pipewire-configuration-enable-pulseaudio? config)
(list (home-pipewire-pulseaudio-shepherd-service config))
'())))
(define (home-pipewire-asoundrc config)
(match-record config <home-pipewire-configuration>
(pipewire)
(mixed-text-file
"asoundrc"
"<" pipewire "/share/alsa/alsa.conf.d/50-pipewire.conf>\n"
"<" pipewire "/share/alsa/alsa.conf.d/99-pipewire-default.conf>\n"
"pcm_type.pipewire {\n"
" lib \"" pipewire "/lib/alsa-lib/libasound_module_pcm_pipewire.so\"\n"
"}\n"
"ctl_type.pipewire {\n"
" lib \"" pipewire "/lib/alsa-lib/libasound_module_ctl_pipewire.so\"\n"
"}\n")))
(define home-pipewire-disable-pulseaudio-auto-start
(plain-file "client.conf" "autospawn = no"))
(define (home-pipewire-xdg-configuration config)
(cons* `("alsa/asoundrc" ,(home-pipewire-asoundrc config))
(if (home-pipewire-configuration-enable-pulseaudio? config)
`(("pulse/client.conf"
,home-pipewire-disable-pulseaudio-auto-start))
'())))
(define home-pipewire-service-type
(service-type
(name 'pipewire)
(extensions
(list (service-extension home-shepherd-service-type
home-pipewire-shepherd-services)
(service-extension home-xdg-configuration-files-service-type
home-pipewire-xdg-configuration)))
(description
"Start essential PipeWire services.")
(default-value (home-pipewire-configuration))))
;;;
;;; PulseAudio support.
;;;
(define (with-pulseaudio-connection sock exp)
;; Wrap EXP in an expression where SOCK is bound to a socket connected to
;; the user's PulseAudio command-line interface socket.
#~(let* ((#$sock (socket AF_UNIX SOCK_STREAM 0))
(pulse-user-file
(lambda (name)
(string-append "/run/user/" (number->string (getuid))
"/pulse/" name)))
(file (pulse-user-file "cli")))
(let loop ((tries 0))
(catch #t
(lambda ()
(connect #$sock AF_UNIX file)
(let ((result #$exp))
(close-port #$sock)
result))
(lambda (key . args)
(if (and (eq? key 'system-error)
(= ENOENT (system-error-errno (cons key args)))
(< tries 3))
;; The CLI socket doesn't exist yet, so send pulseaudio
;; SIGUSR2 so that it creates it and listens to it.
(let ((pid (call-with-input-file (pulse-user-file "pid")
read)))
(when (and (integer? pid) (> pid 1))
(kill pid SIGUSR2))
((@ (fibers) sleep) 1)
(loop (+ tries 1)))
(begin
(close-port #$sock)
(apply throw key args))))))))
(define %pulseaudio-rtp-multicast-address
;; Default address used by 'module-rtp-sink' and 'module-rtp-recv'. This is
;; a multicast address, for the Session Announcement Protocol (SAP) and the
;; Session Description Protocol (SDP).
"224.0.0.56")
(define (pulseaudio-rtp-sink-shepherd-services destination-ip)
(list (shepherd-service
(provision '(pulseaudio-rtp-sink))
(start
#~(lambda* (#:optional (destination-ip #$destination-ip))
#$(with-pulseaudio-connection
#~sock
#~(begin
(display "\
load-module module-null-sink \
sink_name=rtp sink_properties=\"device.description='RTP network output'\"\n"
sock)
(display (string-append "\
load-module module-rtp-send source=rtp.monitor"
(if destination-ip
(string-append
" destination_ip="
destination-ip)
"")
"\n")
sock)
#t))))
(stop
#~(lambda (_)
#$(with-pulseaudio-connection
#~sock
#~(begin
(display "unload-module module-rtp-send\n"
sock)
(display "unload-module module-null-sink\n"
sock)
#f))))
(auto-start? #f))))
(define home-pulseaudio-rtp-sink-service-type
(service-type
(name 'pulseaudio-rtp-sink)
(extensions
(list (service-extension home-shepherd-service-type
pulseaudio-rtp-sink-shepherd-services)))
(description
"Define a PulseAudio sink to broadcast audio output over RTP, which can
then by played by another PulseAudio instance.")
;; By default, send to the SAP multicast address, 224.0.0.56, which can be
;; network-intensive.
(default-value %pulseaudio-rtp-multicast-address)))
(define (pulseaudio-rtp-source-shepherd-services source-ip)
(list (shepherd-service
(provision '(pulseaudio-rtp-source))
(start
#~(lambda* (#:optional (source-ip #$source-ip))
#$(with-pulseaudio-connection
#~sock
#~(begin
(format sock "\
load-module module-rtp-recv sap_address=~a\n" source-ip)
#t))))
(stop
#~(lambda (_)
#$(with-pulseaudio-connection
#~sock
#~(begin
(display "unload-module module-rtp-recv\n"
sock)
#f))))
(auto-start? #f))))
(define home-pulseaudio-rtp-source-service-type
(service-type
(name 'pulseaudio-rtp-source)
(extensions
(list (service-extension home-shepherd-service-type
pulseaudio-rtp-source-shepherd-services)))
(description
"Define a PulseAudio source to receive audio broadcasted over RTP by
another PulseAudio instance.")
(default-value %pulseaudio-rtp-multicast-address)))
