add initial pipewire support

.github/workflows/ci.yml

@@ -71,7 +71,7 @@ jobs:
                         flite1-dev flite
                         libespeak-dev libespeak-ng-dev
                         libttspico-dev
-                        libao-dev libasound2-dev libaudio-dev libpulse-dev libxau-dev libsndfile1-dev
+                        libao-dev libasound2-dev libaudio-dev libpulse-dev libpipewire-0.3-dev libxau-dev libsndfile1-dev
                         libdotconf-dev libglib2.0-dev libltdl-dev systemd
                         gettext help2man texinfo texlive texlive-plain-generic
                         pulseaudio ${{ matrix.deps }}
@@ -127,7 +127,7 @@ jobs:
                         flite1-dev flite
                         libespeak-dev libespeak-ng-dev
                         libttspico-dev
-                        libao-dev libasound2-dev libaudio-dev libpulse-dev libxau-dev libsndfile1-dev
+                        libao-dev libasound2-dev libaudio-dev libpulse-dev libpipewire-0.3-dev libxau-dev libsndfile1-dev
                         libdotconf-dev libglib2.0-dev libltdl-dev- libsystemd-dev systemd
                         gettext help2man texinfo texlive texlive-plain-generic
                         pulseaudio

config/speechd.conf

@@ -197,16 +197,29 @@ SymbolsPreprocFile "symbols-fallback.dic"
 #       "pulse" - PulseAudio
 #       "alsa"  - Advanced Linux Sound System
 #       "oss"   - Open Sound System
+#       "pipewire" -   the new low-latency sound server, for near realtime speech performance
 #       "nas"   - Network Audio System
 #       "libao" - A cross platform audio library
-# Pulse audio is the default and recommended sound server. OSS and ALSA
-# are only provided for compatibility with architectures that do not
-# include Pulse Audio. NAS provides network transparency, but is not
-# very well tested. libao is a cross platform library with plugins for
-# different sound systems and provides alternative output for Pulse Audio
-# and ALSA as well as for other backends.
-
-# AudioOutputMethod "pulse"
+#
+# Pipe Wire is the newest audio output method in this configuration, but not the default one.
+# However, if it works in your deployment, it is recommended because of the
+# latency related advantages it has over pulseaudio and others, however enabling
+# it should be done with precaution, because it isn't tested to work in all
+# configurations supported by speech dispatcher.
+# For now, enabling this is at the discression of the users and packagers of
+# speech dispatcher. However, because we want to eventually make this the default
+# for everyone, trying it in your deployments, if non-critical, is recommended
+#
+# OSS, Pulse Audio and ALSA are only provided for compatibility with
+# architectures that do not include Pipe Wire.
+#
+# NAS provides network transparency, but is not very well tested.
+#
+# libao is a cross platform library with plugins for different sound systems
+# and provides alternative output for Pulse Audio and ALSA as well as for other
+# backends.
+
+# AudioOutputMethod "pipewire"
 
 # -- Pulse Audio parameters --
 

configure.ac

@@ -421,6 +421,22 @@ AC_SUBST([LIBAO_CFLAGS])
 AC_SUBST([LIBAO_LIBS])
 AS_IF([test $with_libao = "yes"], [audio_methods="${audio_methods} libao"])
 
+# check for pipewire support
+AC_ARG_WITH([pipewire],
+	[AS_HELP_STRING([--with-pipewire], [include pipewire support])],
+	[],
+	[with_pipewire=check])
+AS_IF([test $with_pipewire != "no"],
+	[PKG_CHECK_MODULES([pipewire], [libpipewire-0.3],
+		[with_pipewire=yes
+		audio_dlopen_modules="$audio_dlopen_modules -dlopen ../audio/spd_pipewire.la"],
+		[AS_IF([test $with_pipewire = yes],
+			[AC_MSG_FAILURE([pipewire is not available])])])])
+AM_CONDITIONAL([pipewire_support], [test $with_pipewire = "yes"])
+AC_SUBST([pipewire_CFLAGS])
+AC_SUBST([pipewire_LIBS])
+AS_IF([test $with_pipewire = "yes"], [audio_methods="${audio_methods} pipewire"])
+
 # check for alsa support
 AC_ARG_WITH([alsa],
 	[AS_HELP_STRING([--with-alsa], [include ALSA support])],

src/audio/.gitignore

@@ -25,6 +25,7 @@
 /spd_libao.la
 /spd_nas.la
 /spd_oss.la
+/spd_pipewire.la
 /spd_pulse.la
 /tags
 _libs

src/audio/Makefile.am

@@ -63,4 +63,12 @@ spd_pulse_la_LIBADD = $(PULSE_LIBS) $(GLIB_LIBS)
 spd_pulse_la_LDFLAGS = -module -avoid-version
 endif
 
+if pipewire_support
+audio_LTLIBRARIES +=  spd_pipewire.la
+spd_pipewire_la_SOURCES = pipewire.c
+spd_pipewire_la_CPPFLAGS = $(GLIB_CFLAGS) $(inc_local)  $(pipewire_CFLAGS)
+spd_pipewire_la_LIBADD = $(pipewire_LIBS) $(GLIB_LIBS)
+spd_pipewire_la_LDFLAGS = -module -avoid-version
+endif
+
 -include $(top_srcdir)/git.mk