From 20708b28c741b6221d9255eb23f91290de885153 Mon Sep 17 00:00:00 2001
From: George Kiagiadakis <george.kiagiadakis@collabora.com>
Date: Mon, 11 May 2020 11:39:21 +0300
Subject: [PATCH] examples: add a simple audio session management example
---
tests/examples/audiotestsrc-play.c | 436 +++++++++++++++++++++++++++++
tests/examples/meson.build | 10 +
tests/meson.build | 3 +-
3 files changed, 448 insertions(+), 1 deletion(-)
create mode 100644 tests/examples/audiotestsrc-play.c
create mode 100644 tests/examples/meson.build
diff --git a/tests/examples/audiotestsrc-play.c b/tests/examples/audiotestsrc-play.c
new file mode 100644
index 00000000..e0449c93
--- /dev/null
+++ b/tests/examples/audiotestsrc-play.c
@@ -0,0 +1,436 @@
+/* WirePlumber
+ *
+ * Copyright © 2020 Collabora Ltd.
+ * @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/*
+ * This is a very simplistic session manager example that also runs an internal
+ * PipeWire server for ease of use. The PipeWire server runs in its own thread
+ * and our main thread's WpCore (the AppData.core) connects to it through
+ * a socket, as if the PipeWire server was in a different process.
+ *
+ * This example starts 2 media nodes in the media graph: audiotestsrc & alsasink
+ * Then, the session management part constructs endpoints for these nodes
+ * and links them by creating an endpoint link.
+ */
+
+#include <wp/wp.h>
+#include <glib-unix.h>
+#include "../common/test-server.h"
+
+#define APP_ERROR_DOMAIN (app_error_domain_quark ())
+G_DEFINE_QUARK (app-error, app_error_domain)
+
+typedef struct {
+ /* our internal test PipeWire server */
+ WpTestServer server;
+
+ /* cmdline arguments */
+ const gchar *alsa_device;
+
+ /* our main loop and core */
+ GMainContext *context;
+ GMainLoop *loop;
+ WpCore *core;
+ WpSession *session;
+
+ /* nodes provider data */
+ WpNode *audiotestsrc;
+ WpNode *alsasink;
+
+ /* endpoints provider data */
+ WpObjectManager *nodes_om;
+ GPtrArray *session_items;
+
+ /* policy manager data */
+ GSource *interrupt_source;
+
+} AppData;
+
+/*
+ * policy manager: link endpoints together
+ */
+
+static void
+on_endpoints_changed (WpSession * session, AppData * d)
+{
+ g_autoptr (WpEndpoint) src = NULL;
+ g_autoptr (WpEndpoint) sink = NULL;
+
+ g_print ("Endpoints changed, n_endpoints=%u\n",
+ wp_session_get_n_endpoints (session));
+
+ /* a very simplistic lookup, since we don't expect any other endpoints
+ to show up here, but this is the general idea...
+ match endpoints, create links, cache the state and move forward */
+ src = wp_session_lookup_endpoint (session,
+ WP_CONSTRAINT_TYPE_PW_PROPERTY, "media.class", "=s", "Audio/Source", NULL);
+ sink = wp_session_lookup_endpoint (session,
+ WP_CONSTRAINT_TYPE_PW_PROPERTY, "media.class", "=s", "Audio/Sink", NULL);
+
+ if (src) {
+ g_print ("Got endpoint src: %s (%u streams)\n",
+ wp_endpoint_get_name (src),
+ wp_endpoint_get_n_streams (src));
+ }
+ if (sink) {
+ g_print ("Got endpoint sink: %s (%u streams)\n",
+ wp_endpoint_get_name (sink),
+ wp_endpoint_get_n_streams (sink));
+ }
+
+ if (src && sink) {
+ g_autoptr (WpProperties) props = NULL;
+ g_autofree gchar * id =
+ g_strdup_printf ("%u", wp_proxy_get_bound_id (WP_PROXY (sink)));
+
+ /* only the peer endpoint id is required when linking the default streams;
+ everything else will be discovered */
+ props = wp_properties_new ("endpoint-link.input.endpoint", id, NULL);
+ wp_endpoint_create_link (src, props);
+ }
+}
+
+static void
+on_links_changed (WpSession * session, AppData * d)
+{
+ guint n_links = wp_session_get_n_links (session);
+
+ /* activate the link - when endpoint links are created,
+ they don't do anything unless they are activated first */
+ if (n_links == 1) {
+ /* lookup with no constraints will just return the first available object */
+ g_autoptr (WpEndpointLink) link = wp_session_lookup_link (session, NULL);
+
+ g_print ("Requesting link activation...\n");
+ wp_endpoint_link_request_state (link, WP_ENDPOINT_LINK_STATE_ACTIVE);
+ }
+ else if (n_links == 0) {
+ g_print ("Last endpoint link was destroyed; exiting...\n");
+ g_main_loop_quit (d->loop);
+ }
+}
+
+static gboolean
+on_interrupted (AppData * d)
+{
+ g_print ("interrupted; let's try to destroy the link...\n");
+
+ g_autoptr (WpEndpointLink) link = wp_session_lookup_link (d->session, NULL);
+ if (link)
+ wp_proxy_request_destroy (WP_PROXY (link));
+
+ /* remove the interrupt handler so that we can actually
+ interrupt if things get stuck */
+ g_clear_pointer (&d->interrupt_source, g_source_unref);
+ return G_SOURCE_REMOVE;
+}
+
+static void
+start_policy_manager (AppData * d)
+{
+ /* reuse the session pointer that we already have in AppData;
+ under other circumstances, we would retrieve the session
+ with a WpObjectManager */
+ g_signal_connect (d->session, "endpoints-changed",
+ G_CALLBACK (on_endpoints_changed), d);
+ g_signal_connect (d->session, "links-changed",
+ G_CALLBACK (on_links_changed), d);
+
+ d->interrupt_source = g_unix_signal_source_new (SIGINT);
+ g_source_set_callback (d->interrupt_source,
+ G_SOURCE_FUNC (on_interrupted), d, NULL);
+ g_source_attach (d->interrupt_source, d->context);
+}
+
+/*
+ * endpoints provider: creates endpoints for the discovered nodes
+ */
+
+static void
+on_si_exported (WpSessionItem * item, GAsyncResult * res, AppData * d)
+{
+ g_autoptr (GError) error = NULL;
+
+ if (!wp_session_item_export_finish (item, res, &error)) {
+ g_printerr ("Failed to export session item: %s\n", error->message);
+ g_main_loop_quit (d->loop);
+ return;
+ }
+
+ g_print ("Item " WP_OBJECT_FORMAT " exported\n", WP_OBJECT_ARGS (item));
+}
+
+static void
+on_si_activated (WpSessionItem * item, GAsyncResult * res, AppData * d)
+{
+ g_autoptr (GError) error = NULL;
+
+ if (!wp_session_item_activate_finish (item, res, &error)) {
+ g_printerr ("Failed to activate session item: %s\n", error->message);
+ g_main_loop_quit (d->loop);
+ return;
+ }
+
+ g_print ("Item " WP_OBJECT_FORMAT " activated, exporting\n",
+ WP_OBJECT_ARGS (item));
+
+ wp_session_item_export (item, d->session,
+ (GAsyncReadyCallback) on_si_exported, d);
+}
+
+static void
+on_node_added (WpObjectManager * om, WpNode *node, AppData * d)
+{
+ g_autoptr (WpSessionItem) item = NULL;
+ g_auto (GVariantBuilder) b = G_VARIANT_BUILDER_INIT (G_VARIANT_TYPE_VARDICT);
+
+ g_print ("Node " WP_OBJECT_FORMAT " added, creating session item\n",
+ WP_OBJECT_ARGS (node));
+
+ /* load the "si-adapter" Session Item */
+ item = wp_session_item_make (d->core, "si-adapter");
+
+ /* and configure it */
+ g_variant_builder_add (&b, "{sv}", "node",
+ g_variant_new_uint64 ((guint64) node));
+ g_variant_builder_add (&b, "{sv}", "preferred-n-channels",
+ g_variant_new_uint32 (2));
+ if (!wp_session_item_configure (item, g_variant_builder_end (&b))) {
+ g_printerr ("Failed to configure session item\n");
+ g_main_loop_quit (d->loop);
+ return;
+ }
+
+ wp_session_item_activate (item, (GAsyncReadyCallback) on_si_activated, d);
+ g_ptr_array_add (d->session_items, g_steal_pointer (&item));
+}
+
+static void
+start_endpoints_provider (AppData * d)
+{
+ g_print ("Installing watch for nodes...\n");
+
+ /* register a WpObjectManager to listen for available nodes */
+ /* for example purposes, we pretend we don't have access to the data set by
+ start_nodes_provider(), i.e. d->audiotestsrc & d->alsasink */
+ d->nodes_om = wp_object_manager_new ();
+ wp_object_manager_add_interest_1 (d->nodes_om, WP_TYPE_NODE, NULL);
+ wp_object_manager_request_proxy_features (d->nodes_om, WP_TYPE_NODE,
+ WP_PROXY_FEATURES_STANDARD);
+
+ d->session_items = g_ptr_array_new_with_free_func (g_object_unref);
+
+ /* the object manager will emit 'object-added' for every node that is
+ made available, once the node has all the features we requested above */
+ g_signal_connect (d->nodes_om, "object-added", G_CALLBACK (on_node_added), d);
+ wp_core_install_object_manager (d->core, d->nodes_om);
+}
+
+/*
+ * nodes provider: creates the nodes
+ */
+
+static void
+on_node_ready (WpProxy * node, GAsyncResult * res, AppData * d)
+{
+ g_autoptr (GError) error = NULL;
+
+ if (!wp_proxy_augment_finish (node, res, &error)) {
+ g_printerr ("Failed to prepare node: %s\n", error->message);
+ g_main_loop_quit (d->loop);
+ return;
+ }
+
+ g_print ("Node " WP_OBJECT_FORMAT " is ready\n", WP_OBJECT_ARGS (node));
+}
+
+static void
+start_nodes_provider (AppData * d)
+{
+ g_print ("Creating nodes...\n");
+
+ d->audiotestsrc = wp_node_new_from_factory (d->core,
+ "adapter", /* the pipewire factory name */
+ wp_properties_new (
+ /* the spa factory name */
+ "factory.name", "audiotestsrc",
+ /* a friendly name for our node */
+ "node.name", "audiotestsrc",
+ NULL));
+ g_assert (d->audiotestsrc);
+ wp_proxy_augment (WP_PROXY (d->audiotestsrc), WP_PROXY_FEATURES_STANDARD, NULL,
+ (GAsyncReadyCallback) on_node_ready, d);
+
+ d->alsasink = wp_node_new_from_factory (d->core,
+ "adapter", /* the pipewire factory name */
+ wp_properties_new (
+ /* the spa factory name */
+ "factory.name", "api.alsa.pcm.sink",
+ /* a friendly name for our node */
+ "node.name", "alsasink",
+ /* set the device handle (ex. hw:0,0) on the sink */
+ "api.alsa.path", d->alsa_device,
+ NULL));
+ g_assert (d->alsasink);
+ wp_proxy_augment (WP_PROXY (d->alsasink), WP_PROXY_FEATURES_STANDARD, NULL,
+ (GAsyncReadyCallback) on_node_ready, d);
+}
+
+/*
+ * main application: loads modules and the session
+ */
+
+static void
+on_session_ready (WpProxy * session, GAsyncResult * res, AppData * d)
+{
+ g_autoptr (GError) error = NULL;
+
+ if (!wp_proxy_augment_finish (session, res, &error)) {
+ g_printerr ("Failed to prepare session: %s\n", error->message);
+ g_main_loop_quit (d->loop);
+ return;
+ }
+
+ g_print ("Session is ready, starting components...\n");
+
+ start_nodes_provider (d);
+ start_endpoints_provider (d);
+ start_policy_manager (d);
+}
+
+static gboolean
+appdata_init (AppData * d, GError ** error)
+{
+ WpModule *module;
+ WpImplSession *session;
+
+ /* setup the internal test PipeWire server */
+ wp_test_server_setup (&d->server);
+ {
+ /* load server modules (pipewire.conf) */
+ g_autoptr (WpTestServerLocker) lock =
+ wp_test_server_locker_new (&d->server);
+
+ pw_context_add_spa_lib (d->server.context,
+ "audiotestsrc", "audiotestsrc/libspa-audiotestsrc");
+ pw_context_add_spa_lib (d->server.context,
+ "api.alsa.*", "alsa/libspa-alsa");
+
+ if (!pw_context_load_module (d->server.context,
+ "libpipewire-module-spa-node-factory", NULL, NULL)) {
+ g_set_error (error, APP_ERROR_DOMAIN, 0,
+ "Failed to load libpipewire-module-spa-node-factory");
+ return FALSE;
+ }
+ if (!pw_context_load_module (d->server.context,
+ "libpipewire-module-link-factory", NULL, NULL)) {
+ g_set_error (error, APP_ERROR_DOMAIN, 0,
+ "Failed to load libpipewire-module-link-factory");
+ return FALSE;
+ }
+ /* adapter is loaded by pw_context */
+ }
+
+ /* init our main loop */
+ d->context = g_main_context_new ();
+ d->loop = g_main_loop_new (d->context, FALSE);
+
+ /* push the context as the thread default for GTask to work with it,
+ otherwise it will try to use the "default" main context, which we are
+ not using in our main loop, for demonstration purposes */
+ g_main_context_push_thread_default (d->context);
+
+ /* init our core; the "remote.name" key tells it to connect to our
+ test server instead of the default "pipewire-0" */
+ d->core = wp_core_new (d->context, wp_properties_new (
+ "remote.name", d->server.name,
+ NULL));
+
+ /* load wireplumber modules (wireplumber.conf) */
+ if (!(module = wp_module_load (d->core, "C",
+ "libwireplumber-module-si-simple-node-endpoint", NULL, error)))
+ return FALSE;
+
+ if (!(module = wp_module_load (d->core, "C",
+ "libwireplumber-module-si-audio-softdsp-endpoint", NULL, error)))
+ return FALSE;
+
+ if (!(module = wp_module_load (d->core, "C",
+ "libwireplumber-module-si-adapter", NULL, error)))
+ return FALSE;
+
+ if (!(module = wp_module_load (d->core, "C",
+ "libwireplumber-module-si-convert", NULL, error)))
+ return FALSE;
+
+ if (!(module = wp_module_load (d->core, "C",
+ "libwireplumber-module-si-standard-link", NULL, error)))
+ return FALSE;
+
+ /* connect */
+ if (!wp_core_connect (d->core)) {
+ g_set_error (error, APP_ERROR_DOMAIN, 0,
+ "Failed to connect to the test server");
+ return FALSE;
+ }
+
+ g_print ("Creating session...\n");
+
+ /* create a session */
+ d->session = WP_SESSION (session = wp_impl_session_new (d->core));
+ wp_impl_session_set_property (session, "session.name", "audio");
+ wp_proxy_augment (WP_PROXY (session), WP_SESSION_FEATURES_STANDARD, NULL,
+ (GAsyncReadyCallback) on_session_ready, d);
+ return TRUE;
+}
+
+static void
+appdata_clear (AppData * d)
+{
+ /* policy manager data */
+ g_clear_pointer (&d->interrupt_source, g_source_unref);
+
+ /* endpoints provider data */
+ g_clear_pointer (&d->session_items, g_ptr_array_unref);
+ g_clear_object (&d->nodes_om);
+
+ /* nodes provider data */
+ g_clear_object (&d->audiotestsrc);
+ g_clear_object (&d->alsasink);
+
+ /* main app data */
+ g_clear_object (&d->session);
+ g_clear_object (&d->core);
+ g_clear_pointer (&d->loop, g_main_loop_unref);
+ g_clear_pointer (&d->context, g_main_context_unref);
+ wp_test_server_teardown (&d->server);
+}
+
+G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC (AppData, appdata_clear)
+
+gint
+main (gint argc, gchar *argv[])
+{
+ g_auto (AppData) data = {0};
+ g_autoptr (GError) error = NULL;
+
+ pw_init (NULL, NULL);
+ g_log_set_writer_func (wp_log_writer_default, NULL, NULL);
+
+ if (argc > 1)
+ data.alsa_device = argv[1];
+ else
+ data.alsa_device = "hw:0,0";
+
+ if (!appdata_init (&data, &error)) {
+ g_printerr ("Initialization failed:\n %s\n", error->message);
+ return 1;
+ }
+
+ g_main_loop_run (data.loop);
+ return 0;
+}
diff --git a/tests/examples/meson.build b/tests/examples/meson.build
new file mode 100644
index 00000000..2ae87cca
--- /dev/null
+++ b/tests/examples/meson.build
@@ -0,0 +1,10 @@
+executable('audiotestsrc-play',
+ 'audiotestsrc-play.c',
+ c_args : [
+ '-D_GNU_SOURCE',
+ '-DG_LOG_USE_STRUCTURED',
+ '-DG_LOG_DOMAIN="audiotestsrc-play"',
+ ],
+ install: false,
+ dependencies : [giounix_dep, wp_dep, pipewire_dep],
+)
diff --git a/tests/meson.build b/tests/meson.build
index bfec91f9..90cbccf2 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,3 +1,4 @@
-subdir('modules')
subdir('wp')
subdir('wptoml')
+subdir('modules')
+subdir('examples')
--
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