In an earlier discussion, it was mentioned that this can act as a 
drop-in replacement for PulseAudio and JACK, and that the way to move 
forward should be to first migrate it and then see if via a packagegroup 
or feature such a replacement logic can be established. These would be 
reasons for a migration.

On 10.03.21 09:35, Alexander Kanavin wrote:
> But why should it be in oe-core?
>
> Alex
>
> On Wed, 10 Mar 2021 at 08:09, Carlos Rafael Giani via 
> lists.openembedded.org <http://lists.openembedded.org> 
> <crg7475=mailbox.org@lists.openembedded.org 
> <mailto:mailbox.org@lists.openembedded.org>> wrote:
>
>     PipeWire is a new multimedia daemon that aims to be a replacement for
>     both JACK and PulseAudio. Additionally, it provides IO and routing
>     functionality for video. It also has PulseAudio shim to act as a
>     drop-in
>     replacement.
>
>     Signed-off-by: Carlos Rafael Giani <crg7475@mailbox.org
>     <mailto:crg7475@mailbox.org>>
>     ---
>      .../pipewire/pipewire_0.3.23.bb <http://pipewire_0.3.23.bb>      
>            | 272 ++++++++++++++++++
>      1 file changed, 272 insertions(+)
>      create mode 100644
>     meta/recipes-multimedia/pipewire/pipewire_0.3.23.bb
>     <http://pipewire_0.3.23.bb>
>
>     diff --git a/meta/recipes-multimedia/pipewire/pipewire_0.3.23.bb
>     <http://pipewire_0.3.23.bb>
>     b/meta/recipes-multimedia/pipewire/pipewire_0.3.23.bb
>     <http://pipewire_0.3.23.bb>
>     new file mode 100644
>     index 0000000000..1c226b3faf
>     --- /dev/null
>     +++ b/meta/recipes-multimedia/pipewire/pipewire_0.3.23.bb
>     <http://pipewire_0.3.23.bb>
>     @@ -0,0 +1,272 @@
>     +SUMMARY = "Multimedia processing server for Linux"
>     +DESCRIPTION = "Linux server for handling and routing audio and
>     video streams between applications and multimedia I/O devices"
>     +HOMEPAGE = "https://pipewire.org/ <https://pipewire.org/>"
>     +BUGTRACKER  =
>     "https://gitlab.freedesktop.org/pipewire/pipewire/issues
>     <https://gitlab.freedesktop.org/pipewire/pipewire/issues>"
>     +LICENSE = "MIT"
>     +LIC_FILES_CHKSUM = " \
>     +    file://LICENSE;md5=e2c0b7d86d04e716a3c4c9ab34260e69 \
>     +    file://COPYING;md5=97be96ca4fab23e9657ffa590b931c1a \
>     +"
>     +SECTION = "multimedia"
>     +
>     +DEPENDS = "dbus"
>     +
>     +SRCREV = "68f6c75caed047af32320ab4de0c06457457be54"
>     +SRC_URI =
>     "git://gitlab.freedesktop.org/pipewire/pipewire.git;branch=master;protocol=https
>     <http://gitlab.freedesktop.org/pipewire/pipewire.git;branch=master;protocol=https>"
>     +
>     +S = "${WORKDIR}/git"
>     +
>     +inherit meson pkgconfig systemd manpages gettext useradd
>     +
>     +USERADD_PACKAGES = "${PN}"
>     +
>     +GROUPADD_PARAM_${PN} = "--system pipewire"
>     +
>     +USERADD_PARAM_${PN} = "--system --home / --no-create-home \
>     +                       --comment 'PipeWire multimedia daemon' \
>     +                       --gid pipewire --groups audio,video \
>     +                       pipewire"
>     +
>     +# For "EVL", look up https://evlproject.org/
>     <https://evlproject.org/> . It involves
>     +# a specially prepared kernel, and is currently unavailable
>     +# in Yocto.
>     +# FFmpeg and Vulkan aren't really supported - at the current
>     +# stage (version 0.3.23), these are just experiments, not
>     +# actual features.
>     +# libcamera support currently does not build successfully.
>     +# systemd user service files are disabled because per-user
>     +# PipeWire instances aren't really something that makes
>     +# much sense in an embedded environment. A system-wide
>     +# instance does.
>     +EXTRA_OEMESON += " \
>     +    -Daudiotestsrc=true \
>     +    -Devl=false \
>     +    -Dsystemd-user-service=false \
>     +    -Dtests=false \
>     +    -Dudevrulesdir=${nonarch_base_libdir}/udev/rules.d/ \
>     +    -Dvideotestsrc=true \
>     +    -Dffmpeg=false \
>     +    -Dvulkan=false \
>     +    -Dlibcamera=false \
>     +"
>     +
>     +PACKAGECONFIG ??= "\
>     +    ${@bb.utils.contains('DISTRO_FEATURES', 'bluetooth', 'bluez',
>     '', d)} \
>     +    ${@bb.utils.filter('DISTRO_FEATURES', 'alsa systemd', d)} \
>     +    gstreamer jack v4l2 \
>     +"
>     +
>     +# "jack" and "pipewire-jack" packageconfigs cannot be both enabled,
>     +# since "jack" imports libjack, and "pipewire-jack" generates
>     +# libjack.so* files, thus colliding with the libpack package. This
>     +# is why these two are marked in their respective packageconfigs
>     +# as being in conflict.
>     +
>     +PACKAGECONFIG[alsa] = "-Dalsa=true,-Dalsa=false,alsa-lib udev"
>     +PACKAGECONFIG[bluez] = "-Dbluez5=true,-Dbluez5=false,bluez5 sbc"
>     +PACKAGECONFIG[docs] = "-Ddocs=true,-Ddocs=false,doxygen"
>     +PACKAGECONFIG[gstreamer] =
>     "-Dgstreamer=true,-Dgstreamer=false,glib-2.0 gstreamer1.0
>     gstreamer1.0-plugins-base"
>     +PACKAGECONFIG[jack] = "-Djack=true,-Djack=false,jack,,,pipewire-jack"
>     +PACKAGECONFIG[manpages] =
>     "-Dman=true,-Dman=false,libxml-parser-perl-native"
>     +PACKAGECONFIG[sdl2] =
>     "-Dsdl2=enabled,-Dsdl2=disabled,virtual/libsdl2"
>     +PACKAGECONFIG[sndfile] =
>     "-Dsndfile=enabled,-Dsndfile=disabled,libsndfile1"
>     +PACKAGECONFIG[systemd] = "-Dsystemd=true
>     -Dsystemd-system-service=true ,-Dsystemd=false
>     -Dsystemd-system-service=false,systemd"
>     +PACKAGECONFIG[v4l2] = "-Dv4l2=true,-Dv4l2=false,udev"
>     +PACKAGECONFIG[pipewire-alsa] =
>     "-Dpipewire-alsa=true,-Dpipewire-alsa=false,alsa-lib"
>     +PACKAGECONFIG[pipewire-jack] = "-Dpipewire-jack=true
>     -Dlibjack-path=${libdir}/${PW_MODULE_SUBDIR}/jack,-Dpipewire-jack=false,jack,,,jack"
>     +
>     +PACKAGESPLITFUNCS_prepend = " split_dynamic_packages "
>     +PACKAGESPLITFUNCS_append = " set_dynamic_metapkg_rdepends "
>     +
>     +SPA_SUBDIR = "spa-0.2"
>     +PW_MODULE_SUBDIR = "pipewire-0.3"
>     +
>     +remove_unused_installed_files() {
>     +    # jack.conf is used by pipewire-jack (not the JACK SPA plugin).
>     +    # Remove it if pipewire-jack is not built to avoid creating the
>     +    # pipewire-jack package.
>     +    if ${@bb.utils.contains('PACKAGECONFIG', 'pipewire-jack',
>     'false', 'true', d)}; then
>     +        rm -f "${D}${sysconfdir}/pipewire/jack.conf"
>     +    fi
>     +}
>     +
>     +do_install[postfuncs] += "remove_unused_installed_files"
>     +
>     +python split_dynamic_packages () {
>     +    # Create packages for each SPA plugin. These plugins are located
>     +    # in individual subdirectories, so a recursive search is needed.
>     +    spa_libdir = d.expand('${libdir}/${SPA_SUBDIR}')
>     +    do_split_packages(d, spa_libdir, r'^libspa-(.*)\.so$',
>     d.expand('${PN}-spa-plugins-%s'), 'PipeWire SPA plugin for %s',
>     extra_depends='', recursive=True)
>     +
>     +    # Create packages for each PipeWire module.
>     +    pw_module_libdir = d.expand('${libdir}/${PW_MODULE_SUBDIR}')
>     +    do_split_packages(d, pw_module_libdir,
>     r'^libpipewire-module-(.*)\.so$', d.expand('${PN}-modules-%s'),
>     'PipeWire %s module', extra_depends='', recursive=False)
>     +}
>     +
>     +python set_dynamic_metapkg_rdepends () {
>     +    import os
>     +    import oe.utils
>     +
>     +    # Go through all generated SPA plugin and PipeWire module
>     packages
>     +    # (excluding the main package and the -meta package itself) and
>     +    # add them to the -meta package as RDEPENDS.
>     +
>     +    base_pn = d.getVar('PN')
>     +
>     +    spa_pn = base_pn + '-spa-plugins'
>     +    spa_metapkg =  spa_pn + '-meta'
>     +
>     +    pw_module_pn = base_pn + '-modules'
>     +    pw_module_metapkg =  pw_module_pn + '-meta'
>     +
>     +    d.setVar('ALLOW_EMPTY_' + spa_metapkg, "1")
>     +    d.setVar('FILES_' + spa_metapkg, "")
>     +
>     +    d.setVar('ALLOW_EMPTY_' + pw_module_metapkg, "1")
>     +    d.setVar('FILES_' + pw_module_metapkg, "")
>     +
>     +    blacklist = [ spa_pn, spa_metapkg, pw_module_pn,
>     pw_module_metapkg ]
>     +    spa_metapkg_rdepends = []
>     +    pw_module_metapkg_rdepends = []
>     +    pkgdest = d.getVar('PKGDEST')
>     +
>     +    for pkg in oe.utils.packages_filter_out_system(d):
>     +        if pkg in blacklist:
>     +            continue
>     +
>     +        is_spa_pkg = pkg.startswith(spa_pn)
>     +        is_pw_module_pkg = pkg.startswith(pw_module_pn)
>     +        if not is_spa_pkg and not is_pw_module_pkg:
>     +            continue
>     +
>     +        if pkg in spa_metapkg_rdepends or pkg in
>     pw_module_metapkg_rdepends:
>     +            continue
>     +
>     +        # See if the package is empty by looking at the contents
>     of its
>     +        # PKGDEST subdirectory. If this subdirectory is empty,
>     then then
>     +        # package is empty as well. Empty packages do not get
>     added to
>     +        # the meta package's RDEPENDS.
>     +        pkgdir = os.path.join(pkgdest, pkg)
>     +        if os.path.exists(pkgdir):
>     +            dir_contents = os.listdir(pkgdir) or []
>     +        else:
>     +            dir_contents = []
>     +        is_empty = len(dir_contents) == 0
>     +        if not is_empty:
>     +            if is_spa_pkg:
>     +                spa_metapkg_rdepends.append(pkg)
>     +            if is_pw_module_pkg:
>     +                pw_module_metapkg_rdepends.append(pkg)
>     +
>     +    d.setVar('RDEPENDS_' + spa_metapkg, '
>     '.join(spa_metapkg_rdepends))
>     +    d.setVar('DESCRIPTION_' + spa_metapkg, spa_pn + ' meta package')
>     +
>     +    d.setVar('RDEPENDS_' + pw_module_metapkg, '
>     '.join(pw_module_metapkg_rdepends))
>     +    d.setVar('DESCRIPTION_' + pw_module_metapkg, pw_module_pn + '
>     meta package')
>     +}
>     +
>     +PACKAGES =+ "\
>     +    libpipewire \
>     +    ${PN}-tools \
>     +    ${PN}-pulse \
>     +    ${PN}-alsa \
>     +    ${PN}-jack \
>     +    ${PN}-media-session \
>     +    ${PN}-spa-plugins \
>     +    ${PN}-spa-plugins-meta \
>     +    ${PN}-spa-tools \
>     +    ${PN}-modules \
>     +    ${PN}-modules-meta \
>     +    ${PN}-alsa-card-profile \
>     +    gstreamer1.0-pipewire \
>     +"
>     +
>     +PACKAGES_DYNAMIC = "^${PN}-spa-plugins.* ^${PN}-modules.*"
>     +
>     +SYSTEMD_SERVICE_${PN} = "pipewire.service"
>     +CONFFILES_${PN} += "${sysconfdir}/pipewire/pipewire.conf"
>     +FILES_${PN} = " \
>     +    ${sysconfdir}/pipewire/pipewire.conf \
>     +    ${systemd_system_unitdir}/pipewire.* \
>     +    ${bindir}/pipewire \
>     +"
>     +
>     +FILES_${PN}-dev += " \
>     +    ${libdir}/${PW_MODULE_SUBDIR}/jack/libjack*.so \
>     +"
>     +
>     +CONFFILES_libpipewire += "${sysconfdir}/pipewire/client.conf"
>     +FILES_libpipewire = " \
>     +    ${sysconfdir}/pipewire/client.conf \
>     +    ${libdir}/libpipewire-*.so.* \
>     +"
>     +# Add the bare minimum modules and plugins required to be able
>     +# to use libpipewire. Without these, it is essentially unusable.
>     +RDEPENDS_libpipewire += " \
>     +    ${PN}-modules-client-node \
>     +    ${PN}-modules-protocol-native \
>     +    ${PN}-spa-plugins-support \
>     +"
>     +
>     +FILES_${PN}-tools = " \
>     +    ${bindir}/pw-* \
>     +"
>     +
>     +# This is a shim daemon that is intended to be used as a
>     +# drop-in PulseAudio replacement, providing a pulseaudio-compatible
>     +# socket that can be used by applications that use libpulse.
>     +CONFFILES_${PN}-pulse += "${sysconfdir}/pipewire/pipewire-pulse.conf"
>     +FILES_${PN}-pulse = " \
>     +    ${sysconfdir}/pipewire/pipewire-pulse.conf \
>     +    ${bindir}/pipewire-pulse \
>     +"
>     +RDEPENDS_${PN}-pulse += " \
>     +    ${PN}-modules-protocol-pulse \
>     +"
>     +
>     +# alsa plugin to redirect audio to pipewire
>     +FILES_${PN}-alsa = "\
>     +    ${libdir}/alsa-lib/* \
>     +    ${datadir}/alsa/alsa.conf.d/* \
>     +"
>     +
>     +# jack drop-in libraries to redirect audio to pipewire
>     +CONFFILES_${PN}-jack = "${sysconfdir}/pipewire/jack.conf"
>     +FILES_${PN}-jack = "\
>     +    ${sysconfdir}/pipewire/jack.conf \
>     +    ${libdir}/${PW_MODULE_SUBDIR}/jack/libjack*.so.* \
>     +"
>     +
>     +# Example session manager. Not intended for use in production.
>     +CONFFILES_${PN}-media-session =
>     "${sysconfdir}/pipewire/media-session.d/*"
>     +FILES_${PN}-media-session = " \
>     +    ${bindir}/pipewire-media-session \
>     +    ${sysconfdir}/pipewire/media-session.d/* \
>     +"
>     +RPROVIDES_${PN}-media-session = "virtual/pipewire-sessionmanager"
>     +
>     +# Dynamic packages (see set_dynamic_metapkg_rdepends).
>     +FILES_${PN}-spa-plugins = ""
>     +RRECOMMENDS_${PN}-spa-plugins += "${PN}-spa-plugins-meta"
>     +
>     +FILES_${PN}-spa-tools = " \
>     +    ${bindir}/spa-* \
>     +"
>     +
>     +# Dynamic packages (see set_dynamic_metapkg_rdepends).
>     +FILES_${PN}-modules = ""
>     +RRECOMMENDS_${PN}-modules += "${PN}-modules-meta"
>     +
>     +CONFFILES_${PN}-modules-rtkit =
>     "${sysconfdir}/pipewire/client-rt.conf"
>     +FILES_${PN}-modules-rtkit += " \
>     +    ${sysconfdir}/pipewire/client-rt.conf \
>     +    "
>     +
>     +FILES_${PN}-alsa-card-profile = " \
>     +    ${datadir}/alsa-card-profile/* \
>     + ${nonarch_base_libdir}/udev/rules.d/90-pipewire-alsa.rules \
>     +"
>     +
>     +FILES_gstreamer1.0-pipewire = " \
>     +    ${libdir}/gstreamer-1.0/* \
>     +"
>     -- 
>     2.25.1
>
>
>     
>