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authorLudovic Courtès <ludo@gnu.org>2023-03-01 23:08:28 +0100
committerLudovic Courtès <ludo@gnu.org>2023-03-05 23:06:55 +0100
commit674d8933169e018efa3471e4eac52e5ea1e6afee (patch)
treed53413d9885c7fbca6f677fcb345b9e7b749bd1b /gnu/home/services
parent833febb522bd37a38156b558b108372b89a34949 (diff)
downloadguix-674d8933169e018efa3471e4eac52e5ea1e6afee.tar.gz
guix-674d8933169e018efa3471e4eac52e5ea1e6afee.zip
home: services: Add 'pulseaudio-rtp-sink' and 'pulseaudio-rtp-source'.
* gnu/home/services/sound.scm: New file. * gnu/local.mk (GNU_SYSTEM_MODULES): Add it. * doc/guix.texi (Sound Home Services): New section.
Diffstat (limited to 'gnu/home/services')
-rw-r--r--gnu/home/services/sound.scm151
1 files changed, 151 insertions, 0 deletions
diff --git a/gnu/home/services/sound.scm b/gnu/home/services/sound.scm
new file mode 100644
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--- /dev/null
+++ b/gnu/home/services/sound.scm
@@ -0,0 +1,151 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2023 Ludovic Courtès <ludo@gnu.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 (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))
+
+
+;;;
+;;; 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)))