-void speaker_send(int fd, const struct speaker_message *sm, int datafd);
-/* Send a message. DATAFD is passed too if not -1. Does not close DATAFD. */
+/** @brief Speaker process is ready
+ *
+ * This is sent once at startup when the speaker has finished its
+ * initialization. */
+#define SM_READY 132
+
+/** @brief Cancelled track @c id which wasn't playing */
+#define SM_STILLBORN 133
+
+void speaker_send(int fd, const struct speaker_message *sm);
+/* Send a message. */