Add many comments to server/play.c, in advance of possible

[disorder] / lib / speaker-protocol.h

diff --git a/lib/speaker-protocol.h b/lib/speaker-protocol.h
index eb2a1ae116d2316181a907a4bbbba1a2596b7d28..bd80e7d0249f45363d54b4a0c1eda0eeae3fd857 100644 (file)
--- a/lib/speaker-protocol.h
+++ b/lib/speaker-protocol.h
@@ -1,21 +1,19 @@
 /*
  * This file is part of DisOrder
- * Copyright (C) 2005, 2007 Richard Kettlewell
+ * Copyright (C) 2005, 2007, 2008 Richard Kettlewell
  *
- * This program is free software; you can redistribute it and/or modify
+ * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
- * USA
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 /** @file lib/speaker-protocol.h
  * @brief Speaker/server protocol support
@@ -32,7 +30,6 @@ struct speaker_message {
   /** @brief Message type
    *
    * Messges from the main server:
-   * - @ref SM_PREPARE
    * - @ref SM_PLAY
    * - @ref SM_PAUSE
    * - @ref SM_RESUME
@@ -43,6 +40,7 @@ struct speaker_message {
    * - @ref SM_PAUSED
    * - @ref SM_FINISHED
    * - @ref SM_PLAYING
+   * - @ref SM_UNKNOWN
    */
   int type;
 
@@ -54,12 +52,6 @@ struct speaker_message {
 };
 
 /* messages from the main DisOrder server */
-/** @brief Prepare track @c id
- *
- * This message will include a file descriptor.  The speaker starts buffering
- * audio data read from this file against the time that it must be played.
- */
-#define SM_PREPARE 0
 
 /** @brief Play track @c id
  *
@@ -90,19 +82,63 @@ struct speaker_message {
 /** @brief Finished playing track @c id */
 #define SM_FINISHED 129
 
+/** @brief Never heard of track @c id */
+#define SM_UNKNOWN 130
+
 /** @brief Currently track @c id, @c data seconds in
  *
  * This is sent from time to time while a track is playing.
  */
 #define SM_PLAYING 131
 
-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. */
-
-int speaker_recv(int fd, struct speaker_message *sm, int *datafd);
-/* Receive a message.  If DATAFD is not null then can receive an FD.  Return 0
- * on EOF, +ve if a message is read, -1 on EAGAIN, terminates on any other
- * error. */
+/** @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. */
+
+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;
+#define ENDIAN_BIG 1
+#define ENDIAN_LITTLE 2
+#ifdef WORDS_BIGENDIAN
+# define ENDIAN_NATIVE ENDIAN_BIG
+#else
+# define ENDIAN_NATIVE ENDIAN_LITTLE
+#endif
+} attribute((packed));
+
+static inline int formats_equal(const struct stream_header *a,
+                                const struct stream_header *b) {
+  return (a->rate == b->rate
+          && a->channels == b->channels
+          && a->bits == b->bits
+          && a->endian == b->endian);
+}
 
 #endif /* SPEAKER_PROTOCOL_H */