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Diffstat (limited to 'gnu/home/services/sound.scm')
| -rw-r--r-- | gnu/home/services/sound.scm | 151 |
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 index 0000000000..22c1a99250 --- /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))) |