X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/937be4c02816d026de3063f32d82fafda1f3c512..d8b957853160200fe6b00d8c0e8c61a3f62ecd7c:/server/speaker.h

diff --git a/server/speaker.h b/server/speaker.h
index 4e22d38..2288042 100644
--- a/server/speaker.h
+++ b/server/speaker.h
@@ -1,6 +1,6 @@
 /*
  * This file is part of DisOrder
- * Copyright (C) 2005, 2006, 2007 Richard Kettlewell
+ * Copyright (C) 2005-2008 Richard Kettlewell
  *
  * 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
@@ -46,13 +46,14 @@
 #define FRAMES 4096
 
 /** @brief Bytes to send per network packet
+ *
+ * This is the maximum number of bytes we pass to write(2); to determine actual
+ * packet sizes, add a UDP header and an IP header (and a link layer header if
+ * it's the link layer size you care about).
  *
  * Don't make this too big or arithmetic will start to overflow.
  */
-#define NETWORK_BYTES (1024+sizeof(struct rtp_header))
-
-/** @brief Maximum RTP playahead (ms) */
-#define RTP_AHEAD_MS 1000
+#define NETWORK_BYTES (1500-8/*UDP*/-40/*IP*/-8/*conservatism*/)
 
 /** @brief Maximum number of FDs to poll for */
 #define NFDS 256
@@ -87,6 +88,14 @@ struct track {
   /** @brief Slot in @ref fds */
   int slot;
 
+  /** @brief Set when playable
+   *
+   * A track becomes playable whenever it fills its buffer or reaches EOF; it
+   * stops being playable when it entirely empties its buffer.  Tracks start
+   * out life not playable.
+   */
+  int playable;
+  
   /** @brief Input buffer
    *
    * 1Mbyte is enough for nearly 6s of 44100Hz 16-bit stereo
@@ -163,12 +172,20 @@ struct speaker_backend {
   void (*deactivate)(void);
 
   /** @brief Called before poll()
+   * @param timeoutp Pointer to timeout
+   *
+   * Called before the call to poll().
+   *
+   * If desirable, should call addfd() to update the FD array and stash the
+   * slot number somewhere safe.  This will only be called if @ref device_state
+   * is @ref device_open.
+   *
+   * @p timeoutp points to the poll timeout value in milliseconds.  It may be
+   * reduced, but never increased.
    *
-   * Called before the call to poll().  Should call addfd() to update
-   * the FD array and stash the slot number somewhere safe.  This will
-   * only be called if @ref device_state = @ref device_open.
+   * NB you can NOT assume that @c beforepoll is always called before @c play.
    */
-  void (*beforepoll)(void);
+  void (*beforepoll)(int *timeoutp);
 
   /** @brief Called after poll()
    * @return 1 if output device ready for play, 0 otherwise
@@ -213,6 +230,7 @@ extern const struct speaker_backend network_backend;
 extern const struct speaker_backend alsa_backend;
 extern const struct speaker_backend command_backend;
 extern const struct speaker_backend coreaudio_backend;
+extern const struct speaker_backend oss_backend;
 
 extern struct pollfd fds[NFDS];
 extern int fdno;