-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
+
+/** @brief A connection for track @c id arrived */
+#define SM_ARRIVED 134
+
+void speaker_send(int fd, const struct speaker_message *sm);
+/* Send a message. */
+
+int speaker_recv(int fd, struct speaker_message *sm);
+/* Receive a message. Return 0 on EOF, +ve if a message is read, -1 on EAGAIN,
+ * terminates on any other error. */
+
+/** @brief One chunk in a stream */
+struct stream_header {
+ /** @brief Number of bytes */
+ uint32_t nbytes;
+
+ /** @brief Frames per second */
+ uint32_t rate;
+
+ /** @brief Samples per frames */
+ uint8_t channels;
+
+ /** @brief Bits per sample */
+ uint8_t bits;
+
+ /** @brief Endianness */
+ uint8_t endian;
+} attribute((packed));