use gstreamer to play the sound

1 files changed, 78 insertions, 3 deletions

diff --git a/src/sound.c b/src/sound.c
index d92aee8..37c2a8d 100644
--- a/src/sound.c
+++ b/src/sound.c
@@ -19,11 +19,86 @@
 
 #include "sound.h"
 
-#include <gio/gio.h>
+#include <glib.h>
+
+#include <gst/gst.h>
+
+static void
+gst_init_once(void)
+{
+  static gboolean gst_init_checked = FALSE;
+
+  if (G_UNLIKELY(!gst_init_checked))
+    {
+      GError* error = NULL;
+      if (!gst_init_check(NULL, NULL, &error))
+        {
+          g_critical("Unable to play alarm sound: %s", error->message);
+          g_error_free(error);
+        }
+      gst_init_checked = TRUE;
+    }
+}
+
+static gboolean bus_callback(GstBus* bus G_GNUC_UNUSED, GstMessage* msg, gpointer gelement)
+{
+  const GstMessageType message_type = GST_MESSAGE_TYPE(msg);
+
+  if (GST_MESSAGE_SRC(msg) != gelement)
+    return G_SOURCE_CONTINUE;
+
+  /* on eos, cleanup the element and cancel our gst bus subscription */
+  if (message_type == GST_MESSAGE_EOS)
+    {
+      g_debug("got GST_MESSAGE_EOS on sound play");
+      gst_element_set_state(GST_ELEMENT(gelement), GST_STATE_NULL);
+      gst_object_unref(gelement);
+      return G_SOURCE_REMOVE;
+    }
+
+  /* on stream start, set the media role to 'alert' if we're using pulsesink */
+  if (message_type == GST_MESSAGE_STREAM_START)
+    {
+      GstElement* audio_sink = NULL;
+      g_debug("got GST_MESSAGE_STREAM_START on sound play");
+      g_object_get(gelement, "audio-sink", &audio_sink, NULL);
+      if (audio_sink != NULL)
+        {
+          GstPluginFeature* feature;
+          feature = GST_PLUGIN_FEATURE_CAST(GST_ELEMENT_GET_CLASS(audio_sink)->elementfactory);
+          if (feature && g_strcmp0(gst_plugin_feature_get_name(feature), "pulsesink") == 0)
+            {
+              const gchar* const props_str = "props,media.role=alert";
+              GstStructure* props = gst_structure_from_string(props_str, NULL);
+              g_debug("setting audio sink properties to '%s'", props_str);
+              g_object_set(audio_sink, "stream-properties", props, NULL);
+              g_clear_pointer(&props, gst_structure_free);
+            }
+          gst_object_unref(audio_sink);
+        }
+    }
+
+  return G_SOURCE_CONTINUE;
+}
 
 void
-sound_play_file(const char* filename)
+sound_play_uri(const char* uri)
 {
-    g_message("playing sound '%s'", filename);
+  GstElement * element;
+  GstBus * bus;
+
+  gst_init_once();
+
+  element = gst_element_factory_make("playbin", NULL);
+
+  /* start listening for gst events */
+  bus = gst_pipeline_get_bus(GST_PIPELINE(element));
+  gst_bus_add_watch(bus, bus_callback, element);
+  gst_object_unref(bus);
+
+  /* play the sound */
+  g_debug("Playing '%s'", uri);
+  g_object_set(element, "uri", uri, NULL);
+  gst_element_set_state(element, GST_STATE_PLAYING);
 }