PipeWire Media Session: Disable auto port switching on device connect

This is their newer and recommended implementation, I am not using this thing yet. Maybe I will write something here after I will be forced to switch to it.

This is an example implementation and it looks to be very basic but does the job for me.

To disable this unwanted behavior, edit pipewire/media-session.d/media-session.conf. This file is located at the install directory of PipeWire eg.

/usr/share/pipewire/media-session.d/media-session.conf

Read the header in this file to know where to copy it.

Than search for default-routes and comment all occurences of it. (You are free to experiment, this is how I have done it after some trial and error debugging).

The comment near this option in the default list also tells me nothing.

#default-routes         # restore default route

My resulting media-session.conf looks like this:

# Media session config file for PipeWire version "0.3.33" #
#
# Copy and edit this file in /etc/pipewire/media-session.d/
# for systemwide changes or in
# ~/.config/pipewire/media-session.d/ for local changes.

context.properties = {
    # Properties to configure the session and some
    # modules.
    #mem.mlock-all = false
    #support.dbus  = true
    #log.level     = 2
    #alsa.seq.name  = Midi-Bridge
}

context.spa-libs = {
    # Mapping from factory name to library.
    api.bluez5.*    = bluez5/libspa-bluez5
    api.alsa.*      = alsa/libspa-alsa
    api.v4l2.*      = v4l2/libspa-v4l2
    api.libcamera.* = libcamera/libspa-libcamera
}

context.modules = [
    #{   name = <module-name>
    #    [ args = { <key> = <value> ... } ]
    #    [ flags = [ [ ifexists ] [ nofail ] ]
    #}
    #
    # Loads a module with the given parameters.
    # If ifexists is given, the module is ignored when it is not found.
    # If nofail is given, module initialization failures are ignored.
    #
    # Uses RTKit to boost the data thread priority.
    {   name = libpipewire-module-rtkit
        args = {
            #nice.level   = -11
            #rt.prio      = 88
            #rt.time.soft = 2000000
            #rt.time.hard = 2000000
        }
        flags = [ ifexists nofail ]
    }

    # The native communication protocol.
    {   name = libpipewire-module-protocol-native }

    # Allows creating nodes that run in the context of the
    # client. Is used by all clients that want to provide
    # data to PipeWire.
    {   name = libpipewire-module-client-node }

    # Allows creating devices that run in the context of the
    # client. Is used by the session manager.
    {   name = libpipewire-module-client-device }

    # Makes a factory for wrapping nodes in an adapter with a
    # converter and resampler.
    {   name = libpipewire-module-adapter }

    # Allows applications to create metadata objects. It creates
    # a factory for Metadata objects.
    {   name = libpipewire-module-metadata }

    # Provides factories to make session manager objects.
    {   name = libpipewire-module-session-manager }
]

session.modules = {
    # These are the modules that are enabled when a file with
    # the key name is found in the media-session.d config directory.
    # the default bundle is always enabled.

    default = [
        flatpak                 # manages flatpak access
        portal                  # manage portal permissions
        v4l2                    # video for linux udev detection
        #libcamera              # libcamera udev detection
        suspend-node            # suspend inactive nodes
        policy-node             # configure and link nodes
        #metadata               # export metadata API
        #default-nodes          # restore default nodes
        #default-profile        # restore default profiles
        #default-routes         # restore default route
        #streams-follow-default # move streams when default changes
        #alsa-seq               # alsa seq midi support
        #alsa-monitor           # alsa udev detection
        #bluez5                 # bluetooth support
        #bluez5-autoswitch      # automatic bluetooth HSP/HFP profile switch
        #restore-stream         # restore stream settings
        #logind                 # systemd-logind seat support
    ]
    with-audio = [
        metadata
        default-nodes
        default-profile
#        default-routes
        alsa-seq
        alsa-monitor
    ]
    with-alsa = [
        with-audio
    ]
    with-jack = [
        with-audio
    ]
    with-pulseaudio = [
        with-audio
        bluez5
        bluez5-autoswitch
        logind
        restore-stream
        streams-follow-default
    ]
}