filter-chain: add example

run with pipewire -c filter-chain/demonic.conf

src/daemon/filter-chain/demonic.conf

@@ -0,0 +1,100 @@
+# filter-chain example config file for PipeWire version @VERSION@ #
+context.properties = {
+    ## Configure properties in the system.
+    #mem.warn-mlock  = false
+    #mem.allow-mlock = true
+    #mem.mlock-all   = false
+    log.level        = 0
+}
+
+context.spa-libs = {
+    #<factory-name regex> = <library-name>
+    #
+    # Used to find spa factory names. It maps an spa factory name
+    # regular expression to a library name that should contain
+    # that factory.
+    #
+    audio.convert.* = audioconvert/libspa-audioconvert
+    support.*       = support/libspa-support
+}
+
+context.modules = [
+    # Uses RTKit to boost the data thread priority.
+    {   name = libpipewire-module-rtkit
+        args = {
+            #nice.level   = -11
+            #rt.prio      = 88
+            #rt.time.soft = 200000
+            #rt.time.hard = 200000
+        }
+        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 }
+
+    # Makes a factory for wrapping nodes in an adapter with a
+    # converter and resampler.
+    {   name = libpipewire-module-adapter }
+
+    {   name = libpipewire-module-filter-chain
+        args = {
+	    #audio.format = F32
+	    #audio.rate = 48000
+	    audio.channels = 2
+	    #audio.position = [ FL FR ]
+	    node.name = "filter-chain-demonic"
+	    node.description = "Demonic example"
+	    media.name = "Demonic example"
+	    filter.graph = {
+	        nodes = [
+		    {
+		        name = rev
+		        type = ladspa
+	                plugin = revdelay_1605
+	                label = revdelay
+	                control = {
+			    "Delay Time (s)" = 2.0
+                        }
+		    }
+		    {
+		        name = pitch
+		        type = ladspa
+	                plugin = am_pitchshift_1433
+	                label = amPitchshift
+	                control = {
+			    "Pitch shift" = 0.6
+                        }
+		    }
+		    {
+		        name = rev2
+		        type = ladspa
+	                plugin = g2reverb
+	                label = G2reverb
+	                control = {
+                            "Reverb tail" = 0.5
+                            "Damping" = 0.9
+                        }
+		    }
+		]
+		links = [
+		    { output = "rev:Output" input = "pitch:Input" }
+		    { output = "pitch:Output" input = "rev2:In L" }
+		]
+	        inputs = [ "rev:Input" ]
+	        outputs = [ "rev2:Out L" ]
+	    }
+	    capture.props = {
+                #media.class = Audio/Sink
+	    }
+	    playback.props = {
+                #media.class = Audio/Source
+	    }
+	}
+    }
+]

src/daemon/filter-chain/meson.build

@@ -0,0 +1,10 @@
+conf_files = [
+  [ 'demonic.conf', 'demonic.conf' ],
+]
+
+foreach c : conf_files
+  configure_file(input : c.get(0),
+                 output : c.get(1),
+                 configuration : conf_config,
+                 install_dir : conf_install_dir / 'filter-chain')
+endforeach

src/daemon/meson.build

@@ -87,6 +87,7 @@ custom_target('pipewire-uninstalled',
 #  )
 #endif
 
+subdir('filter-chain')
 if not get_option('media-session').disabled()
   subdir('media-session.d')
 endif

src/modules/module-filter-chain.c

@@ -1019,6 +1019,13 @@ static int setup_input_port(struct graph *graph, struct port *port)
 	struct link *link;
 	uint32_t i, n_hndl = port->node->n_hndl;
 
+	if (port->n_links > 1) {
+		pw_log_warn("mixing not implemented yet");
+		 /* FIXME, add a mixer node here, connect all linked peer
+		  * data to the input, make output data, connect to the input
+		  * port */
+	}
+
 	spa_list_for_each(link, &port->link_list, input_link) {
 		struct port *peer = link->output;
 		for (i = 0; i < n_hndl; i++) {