media-session: add module to restore stream settings

src/examples/media-session/media-session.c

@@ -80,6 +80,7 @@ int sm_metadata_start(struct sm_media_session *sess);
 int sm_default_nodes_start(struct sm_media_session *sess);
 int sm_default_profile_start(struct sm_media_session *sess);
 int sm_default_routes_start(struct sm_media_session *sess);
+int sm_restore_stream_start(struct sm_media_session *sess);
 int sm_alsa_midi_start(struct sm_media_session *sess);
 int sm_v4l2_monitor_start(struct sm_media_session *sess);
 int sm_libcamera_monitor_start(struct sm_media_session *sess);
@@ -2017,6 +2018,7 @@ static void do_quit(void *data, int signal_number)
 				"default-nodes,"	\
 				"default-profile,"	\
 				"default-routes,"	\
+				"restore-stream,"	\
 				"alsa-acp,"		\
 				"alsa-seq,"		\
 				"v4l2,"			\
@@ -2038,6 +2040,7 @@ static const struct {
 	{ "default-nodes", "restore default nodes", sm_default_nodes_start, NULL },
 	{ "default-profile", "restore default profiles", sm_default_profile_start, NULL },
 	{ "default-routes", "restore default route", sm_default_routes_start, NULL },
+	{ "restore-stream", "restore stream settings", sm_restore_stream_start, NULL },
 	{ "alsa-seq", "alsa seq midi support", sm_alsa_midi_start, NULL },
 	{ "alsa-pcm", "alsa pcm udev detection", sm_alsa_monitor_start, NULL },
 	{ "alsa-acp", "alsa card profile udev detection", sm_alsa_monitor_start, "alsa.use-acp=true" },

src/examples/media-session/restore-stream.c

@@ -0,0 +1,415 @@
+/* PipeWire
+ *
+ * Copyright © 2020 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 <math.h>
+#include <time.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#include <spa/utils/hook.h>
+#include <spa/utils/result.h>
+#include <spa/pod/parser.h>
+#include <spa/pod/builder.h>
+#include <spa/debug/pod.h>
+
+#include "pipewire/pipewire.h"
+#include "extensions/metadata.h"
+
+#include "media-session.h"
+
+#define NAME		"restore-stream"
+#define SESSION_KEY	"restore-stream"
+
+#define SAVE_INTERVAL	1
+
+struct impl {
+	struct timespec now;
+
+	struct sm_media_session *session;
+	struct spa_hook listener;
+
+	struct pw_context *context;
+	struct spa_source *idle_timeout;
+
+	struct spa_hook meta_listener;
+
+	struct pw_properties *props;
+};
+
+struct stream {
+	struct sm_node *obj;
+
+	uint32_t id;
+	struct impl *impl;
+	char *media_class;
+	char *key;
+	unsigned int restored:1;
+
+	struct spa_hook listener;
+};
+
+struct find_data {
+	struct impl *impl;
+	const char *name;
+	uint32_t id;
+};
+
+static void remove_idle_timeout(struct impl *impl)
+{
+	struct pw_loop *main_loop = pw_context_get_main_loop(impl->context);
+	int res;
+
+	if (impl->idle_timeout) {
+		if ((res = sm_media_session_save_state(impl->session, SESSION_KEY, impl->props)) < 0)
+			pw_log_error("can't save "SESSION_KEY" state: %s", spa_strerror(res));
+		pw_loop_destroy_source(main_loop, impl->idle_timeout);
+		impl->idle_timeout = NULL;
+	}
+}
+
+static void idle_timeout(void *data, uint64_t expirations)
+{
+	struct impl *impl = data;
+	pw_log_debug(NAME " %p: idle timeout", impl);
+	remove_idle_timeout(impl);
+}
+
+static void add_idle_timeout(struct impl *impl)
+{
+	struct timespec value;
+	struct pw_loop *main_loop = pw_context_get_main_loop(impl->context);
+
+	if (impl->idle_timeout == NULL)
+		impl->idle_timeout = pw_loop_add_timer(main_loop, idle_timeout, impl);
+
+	value.tv_sec = SAVE_INTERVAL;
+	value.tv_nsec = 0;
+	pw_loop_update_timer(main_loop, impl->idle_timeout, &value, NULL, false);
+}
+
+static void session_destroy(void *data)
+{
+	struct impl *impl = data;
+	remove_idle_timeout(impl);
+	spa_hook_remove(&impl->listener);
+	pw_properties_free(impl->props);
+	free(impl);
+}
+
+static char *serialize_props(struct stream *str, const struct spa_pod *param)
+{
+	struct spa_pod_prop *prop;
+	struct spa_pod_object *obj = (struct spa_pod_object *) param;
+	float val = 0.0f;
+	bool b = false;
+	char *ptr;
+	const char *v;
+	size_t size;
+	FILE *f;
+
+        f = open_memstream(&ptr, &size);
+
+	SPA_POD_OBJECT_FOREACH(obj, prop) {
+		switch (prop->key) {
+		case SPA_PROP_volume:
+			spa_pod_get_float(&prop->value, &val);
+			fprintf(f, "volume:%f ", val);
+			break;
+		case SPA_PROP_mute:
+			spa_pod_get_bool(&prop->value, &b);
+			fprintf(f, "mute:%d ", b ? 1 : 0);
+			break;
+		case SPA_PROP_channelVolumes:
+		{
+			uint32_t i, n_vals;
+			float vals[SPA_AUDIO_MAX_CHANNELS];
+
+			n_vals = spa_pod_copy_array(&prop->value, SPA_TYPE_Float,
+					vals, SPA_AUDIO_MAX_CHANNELS);
+
+			fprintf(f, "volumes:%d", n_vals);
+			for (i = 0; i < n_vals; i++)
+				fprintf(f, ",%f", vals[i]);
+			break;
+		}
+		default:
+			break;
+		}
+	}
+	if ((v = pw_properties_get(str->obj->obj.props, PW_KEY_NODE_TARGET)) != NULL) {
+		fprintf(f, "target-node:%s", v);
+	}
+        fclose(f);
+	return ptr;
+}
+
+static int handle_props(struct stream *str, struct sm_param *p)
+{
+	struct impl *impl = str->impl;
+	const char *key;
+
+	key = str->key;
+	if (key == NULL)
+		return -EBUSY;
+
+	if (p->param) {
+		char *val = serialize_props(str, p->param);
+		pw_log_debug("stream %d: current props %s %s", str->id, key, val);
+		pw_properties_set(impl->props, key, val);
+		free(val);
+		add_idle_timeout(impl);
+	}
+	return 0;
+}
+
+static int restore_stream(struct stream *str, const char *val)
+{
+	const char *p;
+	char *end;
+	char buf[1024], target[256];
+	struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buf, sizeof(buf));
+	struct spa_pod_frame f[2];
+	struct spa_pod *param;
+	bool mute = false;
+	uint32_t i, n_vols = 0;
+	float *vols, vol;
+
+	spa_pod_builder_push_object(&b, &f[0],
+			SPA_TYPE_OBJECT_Props, SPA_PARAM_Props);
+	for (p = val; *p; p++) {
+		if (strstr(p, "volume:") == p) {
+			vol = strtof(p+7, &end);
+			spa_pod_builder_prop(&b, SPA_PROP_volume, 0);
+			spa_pod_builder_float(&b, vol);
+			p = end;
+		}
+		else if (strstr(p, "mute:") == p) {
+			mute = p[5] == '0' ? false : true;
+			spa_pod_builder_prop(&b, SPA_PROP_mute, 0);
+			spa_pod_builder_bool(&b, mute);
+			p+=6;
+		}
+		else if (strstr(p, "volumes:") == p) {
+			n_vols = strtol(p+8, &end, 10);
+			if (n_vols >= SPA_AUDIO_MAX_CHANNELS)
+				continue;
+			p = end;
+			vols = alloca(n_vols * sizeof(float));
+			for (i = 0; i < n_vols; i++) {
+				vols[i] = strtof(p+1, &end);
+				p = end;
+			}
+			spa_pod_builder_prop(&b, SPA_PROP_channelVolumes, 0);
+			spa_pod_builder_array(&b, sizeof(float), SPA_TYPE_Float,
+					n_vols, vols);
+		}
+		else if (strstr(p, "target-node:") == p) {
+			p += 12;
+			end = strstr(p, " ");
+			if (end == NULL)
+				continue;
+
+			i = end - p;
+			strncpy(target, p, i);
+			target[i-1] = 0;
+		}
+	}
+	param = spa_pod_builder_pop(&b, &f[0]);
+	if (pw_log_level_enabled(SPA_LOG_LEVEL_DEBUG))
+		spa_debug_pod(2, NULL, param);
+
+	pw_node_set_param((struct pw_node*)str->obj->obj.proxy,
+			SPA_PARAM_Props, 0, param);
+	return 0;
+}
+
+static void update_key(struct stream *str)
+{
+	struct impl *impl = str->impl;
+	uint32_t i;
+	const char *p, *val;
+	char *key;
+	struct sm_object *obj = &str->obj->obj;
+	bool changed;
+	const char *keys[] = {
+		PW_KEY_MEDIA_ROLE,
+		PW_KEY_APP_ID,
+		PW_KEY_APP_NAME,
+		PW_KEY_MEDIA_NAME,
+	};
+
+	key = NULL;
+	for (i = 0; i < SPA_N_ELEMENTS(keys); i++) {
+		if ((p = pw_properties_get(obj->props, keys[i]))) {
+			key = spa_aprintf("%s-%s:%s", str->media_class, keys[i], p);
+			break;
+		}
+	}
+	if (key == NULL)
+		return;
+
+	pw_log_debug(NAME " %p: stream %p key '%s'", impl, str, key);
+	changed = str->key == NULL || strcmp(str->key, key) != 0;
+	free(str->key);
+	str->key = key;
+	if (!changed || str->restored)
+		return;
+
+	val = pw_properties_get(impl->props, key);
+	if (val != NULL) {
+		pw_log_info("stream %d: restore '%s' to %s", str->id, key, val);
+		restore_stream(str, val);
+		str->restored = true;
+	}
+}
+
+static void object_update(void *data)
+{
+	struct stream *str = data;
+	struct impl *impl = str->impl;
+	bool rescan = false;
+
+	pw_log_debug(NAME" %p: stream %p %08x/%08x", impl, str,
+			str->obj->obj.changed, str->obj->obj.avail);
+
+	if (str->obj->obj.changed & SM_OBJECT_CHANGE_MASK_PROPERTIES) {
+		if (str->key == NULL)
+			update_key(str);
+	}
+	if (str->obj->obj.changed & SM_NODE_CHANGE_MASK_PARAMS)
+		rescan = true;
+
+	if (rescan) {
+		struct sm_param *p;
+		spa_list_for_each(p, &str->obj->param_list, link) {
+			if (pw_log_level_enabled(SPA_LOG_LEVEL_DEBUG))
+				spa_debug_pod(2, NULL, p->param);
+
+			switch (p->id) {
+			case SPA_PARAM_Props:
+				handle_props(str, p);
+				break;
+			default:
+				break;
+			}
+		}
+	}
+}
+
+static const struct sm_object_events object_events = {
+	SM_VERSION_OBJECT_EVENTS,
+	.update = object_update
+};
+
+static void session_create(void *data, struct sm_object *object)
+{
+	struct impl *impl = data;
+	struct stream *str;
+	const char *media_class;
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Node) != 0 ||
+	    object->props == NULL ||
+	    (media_class = pw_properties_get(object->props, PW_KEY_MEDIA_CLASS)) == NULL ||
+	    strstr(media_class, "Stream/") != media_class)
+		return;
+
+	media_class += strlen("Stream/");
+
+	pw_log_debug(NAME " %p: add stream '%d' %s", impl, object->id, media_class);
+
+	str = sm_object_add_data(object, SESSION_KEY, sizeof(struct stream));
+	str->obj = (struct sm_node*)object;
+	str->id = object->id;
+	str->impl = impl;
+	str->media_class = strdup(media_class);
+	update_key(str);
+
+	str->obj->obj.mask |= SM_OBJECT_CHANGE_MASK_PROPERTIES | SM_NODE_CHANGE_MASK_PARAMS;
+	sm_object_add_listener(&str->obj->obj, &str->listener, &object_events, str);
+}
+
+static void destroy_stream(struct impl *impl, struct stream *str)
+{
+	remove_idle_timeout(impl);
+	spa_hook_remove(&str->listener);
+	free(str->media_class);
+	free(str->key);
+	sm_object_remove_data((struct sm_object*)str->obj, SESSION_KEY);
+}
+
+static void session_remove(void *data, struct sm_object *object)
+{
+	struct impl *impl = data;
+	struct stream *str;
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Node) != 0)
+		return;
+
+	pw_log_debug(NAME " %p: remove node '%d'", impl, object->id);
+
+	if ((str = sm_object_get_data(object, SESSION_KEY)) != NULL)
+		destroy_stream(impl, str);
+}
+
+static const struct sm_media_session_events session_events = {
+	SM_VERSION_MEDIA_SESSION_EVENTS,
+	.create = session_create,
+	.remove = session_remove,
+	.destroy = session_destroy,
+};
+
+int sm_restore_stream_start(struct sm_media_session *session)
+{
+	struct impl *impl;
+	int res;
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		return -errno;
+
+	impl->session = session;
+	impl->context = session->context;
+
+	impl->props = pw_properties_new(NULL, NULL);
+	if (impl->props == NULL) {
+		res = -errno;
+		goto exit_free;
+	}
+
+	if ((res = sm_media_session_load_state(impl->session, SESSION_KEY, impl->props)) < 0)
+		pw_log_info("can't load "SESSION_KEY" state: %s", spa_strerror(res));
+
+	sm_media_session_add_listener(impl->session, &impl->listener, &session_events, impl);
+
+	return 0;
+
+exit_free:
+	free(impl);
+	return res;
+}

src/examples/meson.build

@@ -81,6 +81,7 @@ if alsa_dep.found()
     'media-session/session-manager.c',
     'media-session/metadata.c',
     'media-session/stream-endpoint.c',
+    'media-session/restore-stream.c',
     'media-session/policy-ep.c',
     'media-session/policy-node.c',
     'media-session/v4l2-monitor.c',