GSTREAMER回调不起作用GmainContext

Question

我有此示例应用程序，其中创建gmainContext并在创建G_Main_loop时使用它。

GstElement *pipeline;
GstBus *bus;
guint bus_watch_id;

/* init */
gst_init(&argc, &argv);

/* create pipeline, add handler */
pipeline = gst_pipeline_new("my_pipeline");

/* adds a watch for new message on our pipeline's message bus to
 * the default GLib main context, which is the main context that our
 * GLib main loop is attached to below
 */
bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));

GstElement *filesrc = gst_element_factory_make("filesrc", "filesrc");
g_assert(filesrc);
g_object_set(filesrc, "location", "sample.wav", NULL);

GstElement *udpsink = gst_element_factory_make("udpsink", "udpsink");
g_assert(udpsink);
g_object_set(udpsink, "port", 6666, NULL);

gst_bin_add_many(GST_BIN(pipeline), filesrc, udpsink, NULL);
gst_element_link_many(filesrc, udpsink, NULL);

gst_bus_add_signal_watch(bus);
g_signal_connect(bus, "message::error", G_CALLBACK(my_bus_callback), NULL);
g_signal_connect(bus, "message::eos", G_CALLBACK(my_bus_callback), NULL);

gst_element_set_state(pipeline, GST_STATE_PLAYING);
GMainContext *context = g_main_context_new();

loop = g_main_loop_new(context, FALSE);
g_main_loop_run(loop);

/* clean up */
gst_element_set_state(pipeline, GST_STATE_NULL);
gst_object_unref(pipeline);
// g_source_remove (bus_watch_id);
g_main_loop_unref(loop);

这样，我没有得到任何回调。因此，g_signal_connect不起作用。但是，如果我在创建g_main_loop时不通过上下文，则可以按预期工作。如何使其与gmaincontext一起使用？

Answer 1

gst_bus_add_signal_watch在默认主上下文上工作。
g_main_context_push_thread_default需要调用以使用新创建的上下文。