impl-device: add support for adapter

Make it possible to wrap nodes created by a device in a wrapper such
as adapter.

Update the minimal.conf to use udev to detect and configure devices and
nodes. Add a config switch to switch back to hardcoded config.

src/daemon/minimal.conf.in

@@ -44,6 +44,10 @@ context.properties = {
     vm.overrides = {
         default.clock.min-quantum = 1024
     }
+
+    # This config can use udev or hardcoded ALSA devices. Make sure to
+    # change the alsa device below when disabling udev
+    minimal.use-udev = true
 }
 
 context.spa-libs = {
@@ -54,6 +58,7 @@ context.spa-libs = {
     # that factory.
     #
     audio.convert.* = audioconvert/libspa-audioconvert
+    audio.adapt     = audioconvert/libspa-audioconvert
     api.alsa.*      = alsa/libspa-alsa
     support.*       = support/libspa-support
 }
@@ -99,6 +104,8 @@ context.modules = [
     # context of the PipeWire server.
     { name = libpipewire-module-spa-node-factory }
 
+    { name = libpipewire-module-spa-device-factory }
+
     # Allows creating nodes that run in the context of the
     # client. Is used by all clients that want to provide
     # data to PipeWire.
@@ -183,6 +190,33 @@ context.objects = [
         }
     }
 
+    # This creates a ALSA udev device that will enumerate all
+    # ALSA devices. Because it is using ACP and has the audio-profile
+    # property set, this will enable a profile and create associated
+    # nodes, which will be automatically configured to their best
+    # configuration.
+    { factory = spa-device-factory
+        args = {
+            factory.name           = api.alsa.enum.udev
+            alsa.use-acp = true
+            device.object.properties = {
+                api.acp.auto-profile = true
+                api.acp.auto-port = true
+                device.object.properties = {
+                    node.adapter             = audio.adapt
+                    resample.disable         = true
+                    adapter.auto-port-config = {
+                        mode = dsp
+                        monitor = false
+                        control = false
+                        position = unknown   # unknown, preserve
+                    }
+                }
+            }
+        }
+        condition = [ { minimal.use-udev = true } ]
+    }
+
     # This creates a single PCM source device for the given
     # alsa device path hw:0. You can change source to sink
     # to make a sink in the same way.
@@ -222,7 +256,7 @@ context.objects = [
             #channelmix.rear-delay  = 12.0
             #channelmix.stereo-widen = 0.0
             #channelmix.hilbert-taps = 0
-            channelmix.disable     = true
+            #channelmix.disable     = false
             #dither.noise = 0
             #node.param.Props      = {
             #    params = [
@@ -248,6 +282,7 @@ context.objects = [
             #    }
             #}
         }
+        condition = [ { minimal.use-udev = false } ]
     }
     { factory = adapter
         args = {
@@ -284,7 +319,7 @@ context.objects = [
             #channelmix.rear-delay = 12.0
             #channelmix.stereo-widen = 0.0
             #channelmix.hilbert-taps = 0
-            channelmix.disable     = true
+            #channelmix.disable     = false
             #dither.noise = 0
             #node.param.Props      = {
             #    params = [
@@ -310,6 +345,7 @@ context.objects = [
             #    }
             #}
         }
+        condition = [ { minimal.use-udev = false } ]
     }
     # This creates a new Source node. It will have input ports
     # that you can link, to provide audio for this source.

src/pipewire/impl-device.c

@@ -67,6 +67,7 @@ struct object_data {
 #define OBJECT_DEVICE	1
 	uint32_t type;
 	struct spa_handle *handle;
+	struct spa_handle *subhandle;
 	void *object;
 	struct spa_hook listener;
 };
@@ -610,6 +611,8 @@ static void on_object_free(void *data)
 {
 	struct object_data *od = data;
 	pw_unload_spa_handle(od->handle);
+	if (od->subhandle)
+		pw_unload_spa_handle(od->subhandle);
 }
 
 static const struct pw_impl_node_events node_object_events = {
@@ -765,11 +768,12 @@ static void device_add_object(struct pw_impl_device *device, uint32_t id,
 		const struct spa_device_object_info *info)
 {
 	struct pw_context *context = device->context;
-	struct spa_handle *handle;
+	struct spa_handle *handle, *subhandle = NULL;
 	spa_autoptr(pw_properties) props = NULL;
 	int res;
 	void *iface;
 	struct object_data *od = NULL;
+	const char *str;
 
 	if (info->factory_name == NULL) {
 		pw_log_debug("%p: missing factory name", device);
@@ -801,6 +805,31 @@ static void device_add_object(struct pw_impl_device *device, uint32_t id,
 
 	if (spa_streq(info->type, SPA_TYPE_INTERFACE_Node)) {
 		struct pw_impl_node *node;
+		const struct pw_properties *p;
+
+		p = pw_context_get_properties(context);
+		pw_properties_set(props, "clock.quantum-limit",
+				pw_properties_get(p, "default.clock.quantum-limit"));
+
+		if ((str = pw_properties_get(props, "node.adapter")) != NULL) {
+			char name[64];
+			snprintf(name, sizeof(name), "%s.follower", str);
+	                pw_properties_setf(props, name, "pointer:%p", iface);
+
+			subhandle = handle;
+
+			handle = pw_context_load_spa_handle(context, str, &props->dict);
+			if (handle == NULL) {
+				pw_log_warn("%p: can't load handle %s: %m", device, str);
+				goto cleanup;
+			}
+			if ((res = spa_handle_get_interface(handle, info->type, &iface)) < 0) {
+				pw_log_error("%p: can't get %s interface: %s", device, info->type,
+						spa_strerror(res));
+				goto cleanup;
+			}
+		}
+
 		node = pw_context_create_node(context, spa_steal_ptr(props),
 				sizeof(struct object_data));
 		if (node == NULL)
@@ -830,6 +859,7 @@ static void device_add_object(struct pw_impl_device *device, uint32_t id,
 	if (od) {
 		od->id = id;
 		od->handle = handle;
+		od->subhandle = subhandle;
 		spa_list_append(&device->object_list, &od->link);
 		if (device->global)
 			object_register(od, device->info.id);
@@ -839,6 +869,8 @@ static void device_add_object(struct pw_impl_device *device, uint32_t id,
 cleanup:
 	if (handle)
 		pw_unload_spa_handle(handle);
+	if (subhandle)
+		pw_unload_spa_handle(subhandle);
 	return;
 }