1 files changed, 473 insertions, 0 deletions

diff --git a/src/modules/module-fallback-sink.c b/src/modules/module-fallback-sink.c
new file mode 100644
index 0000000..9a277d1
--- /dev/null
+++ b/src/modules/module-fallback-sink.c
@@ -0,0 +1,473 @@
+/* PipeWire
+ *
+ * Copyright © 2021 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#include <spa/utils/result.h>
+#include <spa/utils/string.h>
+#include <spa/param/audio/raw.h>
+
+#include <pipewire/impl.h>
+#include <pipewire/i18n.h>
+
+/** \page page_module_fallback_sink PipeWire Module: Fallback Sink
+ *
+ * Fallback sink, which appear dynamically when no other sinks are
+ * present. This is only useful for Pulseaudio compatibility.
+ */
+
+#define NAME "fallback-sink"
+
+#define DEFAULT_SINK_NAME		"auto_null"
+#define DEFAULT_SINK_DESCRIPTION	_("Dummy Output")
+
+PW_LOG_TOPIC_STATIC(mod_topic, "mod." NAME);
+#define PW_LOG_TOPIC_DEFAULT mod_topic
+
+#define MODULE_USAGE	("[ sink.name=<str> ] " \
+			"[ sink.description=<str> ] ")
+
+static const struct spa_dict_item module_props[] = {
+	{ PW_KEY_MODULE_AUTHOR, "Pauli Virtanen <pav@iki.fi>" },
+	{ PW_KEY_MODULE_DESCRIPTION, "Dynamically appearing fallback sink" },
+	{ PW_KEY_MODULE_USAGE, MODULE_USAGE },
+	{ PW_KEY_MODULE_VERSION, PACKAGE_VERSION },
+};
+
+struct bitmap {
+	uint8_t *data;
+	size_t size;
+	size_t items;
+};
+
+struct impl {
+	struct pw_context *context;
+
+	struct pw_impl_module *module;
+	struct spa_hook module_listener;
+
+	struct pw_core *core;
+	struct pw_registry *registry;
+	struct pw_proxy *sink;
+
+	struct spa_hook core_listener;
+	struct spa_hook core_proxy_listener;
+	struct spa_hook registry_listener;
+	struct spa_hook sink_listener;
+
+	struct pw_properties *properties;
+
+	struct bitmap sink_ids;
+	struct bitmap fallback_sink_ids;
+
+	int check_seq;
+
+	unsigned int do_disconnect:1;
+	unsigned int scheduled:1;
+};
+
+static int bitmap_add(struct bitmap *map, uint32_t i)
+{
+	const uint32_t pos = (i >> 3);
+	const uint8_t mask = 1 << (i & 0x7);
+
+	if (pos >= map->size) {
+		size_t new_size = map->size + pos + 16;
+		void *p;
+
+		p = realloc(map->data, new_size);
+		if (!p)
+			return -errno;
+
+		memset((uint8_t*)p + map->size, 0, new_size - map->size);
+		map->data = p;
+		map->size = new_size;
+	}
+
+	if (map->data[pos] & mask)
+		return 1;
+
+	map->data[pos] |= mask;
+	++map->items;
+
+	return 0;
+}
+
+static bool bitmap_remove(struct bitmap *map, uint32_t i)
+{
+	const uint32_t pos = (i >> 3);
+	const uint8_t mask = 1 << (i & 0x7);
+
+	if (pos >= map->size)
+		return false;
+
+	if (!(map->data[pos] & mask))
+		return false;
+
+	map->data[pos] &= ~mask;
+	--map->items;
+
+	return true;
+}
+
+static void bitmap_free(struct bitmap *map)
+{
+	free(map->data);
+	spa_zero(*map);
+}
+
+static int add_id(struct bitmap *map, uint32_t id)
+{
+	int res;
+
+	if (id == SPA_ID_INVALID)
+		return -EINVAL;
+
+	if ((res = bitmap_add(map, id)) < 0)
+	       pw_log_error("%s", spa_strerror(res));
+
+	return res;
+}
+
+static void reschedule_check(struct impl *impl)
+{
+	if (!impl->scheduled)
+		return;
+
+	impl->check_seq = pw_core_sync(impl->core, 0, impl->check_seq);
+}
+
+static void schedule_check(struct impl *impl)
+{
+	if (impl->scheduled)
+		return;
+
+	impl->scheduled = true;
+	impl->check_seq = pw_core_sync(impl->core, 0, impl->check_seq);
+}
+
+static void sink_proxy_removed(void *data)
+{
+	struct impl *impl = data;
+
+	pw_proxy_destroy(impl->sink);
+}
+
+static void sink_proxy_bound(void *data, uint32_t id)
+{
+	struct impl *impl = data;
+
+	add_id(&impl->sink_ids, id);
+	add_id(&impl->fallback_sink_ids, id);
+
+	reschedule_check(impl);
+	schedule_check(impl);
+}
+
+static void sink_proxy_destroy(void *data)
+{
+	struct impl *impl = data;
+
+	pw_log_debug("fallback dummy sink destroyed");
+
+	spa_hook_remove(&impl->sink_listener);
+	impl->sink = NULL;
+}
+
+static const struct pw_proxy_events sink_proxy_events = {
+	PW_VERSION_PROXY_EVENTS,
+	.removed = sink_proxy_removed,
+	.bound = sink_proxy_bound,
+	.destroy = sink_proxy_destroy,
+};
+
+static int sink_create(struct impl *impl)
+{
+	if (impl->sink)
+		return 0;
+
+	pw_log_info("creating fallback dummy sink");
+
+	impl->sink = pw_core_create_object(impl->core,
+			"adapter", PW_TYPE_INTERFACE_Node, PW_VERSION_NODE,
+			impl->properties ? &impl->properties->dict : NULL, 0);
+	if (impl->sink == NULL)
+		return -errno;
+
+	pw_proxy_add_listener(impl->sink, &impl->sink_listener, &sink_proxy_events, impl);
+
+	return 0;
+}
+
+static void sink_destroy(struct impl *impl)
+{
+	if (!impl->sink)
+		return;
+
+	pw_log_info("removing fallback dummy sink");
+	pw_proxy_destroy(impl->sink);
+}
+
+static void check_sinks(struct impl *impl)
+{
+	int res;
+
+	pw_log_debug("seeing %zu sink(s), %zu fallback sink(s)",
+			impl->sink_ids.items, impl->fallback_sink_ids.items);
+
+	if (impl->sink_ids.items > impl->fallback_sink_ids.items) {
+		sink_destroy(impl);
+	} else {
+		if ((res = sink_create(impl)) < 0)
+			pw_log_error("error creating sink: %s", spa_strerror(res));
+	}
+}
+
+static void registry_event_global(void *data, uint32_t id,
+		uint32_t permissions, const char *type, uint32_t version,
+		const struct spa_dict *props)
+{
+	struct impl *impl = data;
+	const char *str;
+
+	reschedule_check(impl);
+
+	if (!props)
+		return;
+
+	if (!spa_streq(type, PW_TYPE_INTERFACE_Node))
+		return;
+
+	str = spa_dict_lookup(props, PW_KEY_MEDIA_CLASS);
+	if (!(spa_streq(str, "Audio/Sink") || spa_streq(str, "Audio/Sink/Virtual")))
+		return;
+
+	add_id(&impl->sink_ids, id);
+	schedule_check(impl);
+}
+
+static void registry_event_global_remove(void *data, uint32_t id)
+{
+	struct impl *impl = data;
+
+	reschedule_check(impl);
+
+	bitmap_remove(&impl->fallback_sink_ids, id);
+	if (bitmap_remove(&impl->sink_ids, id))
+		schedule_check(impl);
+}
+
+static const struct pw_registry_events registry_events = {
+	PW_VERSION_REGISTRY_EVENTS,
+	.global = registry_event_global,
+	.global_remove = registry_event_global_remove,
+};
+
+static void core_done(void *data, uint32_t id, int seq)
+{
+	struct impl *impl = data;
+
+	if (seq == impl->check_seq) {
+		impl->scheduled = false;
+		check_sinks(impl);
+	}
+}
+
+static const struct pw_core_events core_events = {
+	PW_VERSION_CORE_EVENTS,
+	.done = core_done,
+};
+
+static void core_proxy_removed(void *data)
+{
+	struct impl *impl = data;
+
+	if (impl->registry) {
+		spa_hook_remove(&impl->registry_listener);
+		pw_proxy_destroy((struct pw_proxy*)impl->registry);
+		impl->registry = NULL;
+	}
+}
+
+static void core_proxy_destroy(void *data)
+{
+	struct impl *impl = data;
+
+	spa_hook_remove(&impl->core_listener);
+	spa_hook_remove(&impl->core_proxy_listener);
+	impl->core = NULL;
+}
+
+static const struct pw_proxy_events core_proxy_events = {
+	PW_VERSION_PROXY_EVENTS,
+	.destroy = core_proxy_destroy,
+	.removed = core_proxy_removed,
+};
+
+static void impl_destroy(struct impl *impl)
+{
+	sink_destroy(impl);
+
+	if (impl->registry) {
+		spa_hook_remove(&impl->registry_listener);
+		pw_proxy_destroy((struct pw_proxy*)impl->registry);
+		impl->registry = NULL;
+	}
+
+	if (impl->core) {
+		spa_hook_remove(&impl->core_listener);
+		spa_hook_remove(&impl->core_proxy_listener);
+		if (impl->do_disconnect)
+			pw_core_disconnect(impl->core);
+		impl->core = NULL;
+	}
+
+	if (impl->properties) {
+		pw_properties_free(impl->properties);
+		impl->properties = NULL;
+	}
+
+	bitmap_free(&impl->sink_ids);
+	bitmap_free(&impl->fallback_sink_ids);
+
+	free(impl);
+}
+
+static void module_destroy(void *data)
+{
+	struct impl *impl = data;
+	spa_hook_remove(&impl->module_listener);
+	impl_destroy(impl);
+}
+
+static const struct pw_impl_module_events module_events = {
+	PW_VERSION_IMPL_MODULE_EVENTS,
+	.destroy = module_destroy,
+};
+
+SPA_EXPORT
+int pipewire__module_init(struct pw_impl_module *module, const char *args)
+{
+	struct pw_context *context = pw_impl_module_get_context(module);
+	struct pw_properties *props = NULL;
+	struct impl *impl = NULL;
+	const char *str;
+	int res;
+
+	PW_LOG_TOPIC_INIT(mod_topic);
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		goto error_errno;
+
+	pw_log_debug("module %p: new %s", impl, args);
+
+	if (args == NULL)
+		args = "";
+
+	impl->module = module;
+	impl->context = context;
+
+	props = pw_properties_new_string(args);
+	if (props == NULL)
+		goto error_errno;
+
+	impl->properties = pw_properties_new(NULL, NULL);
+	if (impl->properties == NULL)
+		goto error_errno;
+
+	if ((str = pw_properties_get(props, "sink.name")) == NULL)
+		str = DEFAULT_SINK_NAME;
+	pw_properties_set(impl->properties, PW_KEY_NODE_NAME, str);
+
+	if ((str = pw_properties_get(props, "sink.description")) == NULL)
+		str = DEFAULT_SINK_DESCRIPTION;
+	pw_properties_set(impl->properties, PW_KEY_NODE_DESCRIPTION, str);
+
+	pw_properties_setf(impl->properties, SPA_KEY_AUDIO_RATE, "%u", 48000);
+	pw_properties_setf(impl->properties, SPA_KEY_AUDIO_CHANNELS, "%u", 2);
+	pw_properties_set(impl->properties, SPA_KEY_AUDIO_POSITION, "FL,FR");
+
+	pw_properties_set(impl->properties, PW_KEY_MEDIA_CLASS, "Audio/Sink");
+	pw_properties_set(impl->properties, PW_KEY_FACTORY_NAME, "support.null-audio-sink");
+	pw_properties_set(impl->properties, PW_KEY_NODE_VIRTUAL, "true");
+	pw_properties_set(impl->properties, "monitor.channel-volumes", "true");
+
+	impl->core = pw_context_get_object(impl->context, PW_TYPE_INTERFACE_Core);
+	if (impl->core == NULL) {
+		str = pw_properties_get(props, PW_KEY_REMOTE_NAME);
+		impl->core = pw_context_connect(impl->context,
+				pw_properties_new(
+					PW_KEY_REMOTE_NAME, str,
+					NULL),
+				0);
+		impl->do_disconnect = true;
+	}
+	if (impl->core == NULL) {
+		res = -errno;
+		pw_log_error("can't connect: %m");
+		goto error;
+	}
+
+	pw_proxy_add_listener((struct pw_proxy*)impl->core,
+			&impl->core_proxy_listener, &core_proxy_events,
+			impl);
+
+	pw_core_add_listener(impl->core, &impl->core_listener, &core_events, impl);
+
+	impl->registry = pw_core_get_registry(impl->core,
+			PW_VERSION_REGISTRY, 0);
+	if (impl->registry == NULL)
+		goto error_errno;
+
+	pw_registry_add_listener(impl->registry,
+			&impl->registry_listener,
+			&registry_events, impl);
+
+	pw_impl_module_add_listener(module, &impl->module_listener, &module_events, impl);
+
+	pw_impl_module_update_properties(module, &SPA_DICT_INIT_ARRAY(module_props));
+
+	schedule_check(impl);
+
+	pw_properties_free(props);
+	return 0;
+
+error_errno:
+	res = -errno;
+error:
+	if (props)
+		pw_properties_free(props);
+	if (impl)
+		impl_destroy(impl);
+	return res;
+}