mdw@git.distorted.org.uk Git - disorder/blob - lib/speaker-protocol.h

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2005, 2007, 2008 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/speaker-protocol.h
  19  * @brief Speaker/server protocol support
  20  *
  21  * This file defines the protocol by which the main server and the speaker
  22  * process communicate.
  23  */
  24
  25 #ifndef SPEAKER_PROTOCOL_H
  26 #define SPEAKER_PROTOCOL_H
  27
  28 #include "byte-order.h"
  29
  30 /** @brief A message from the main server to the speaker, or vica versa */
  31 struct speaker_message {
  32   /** @brief Message type
  33    *
  34    * Messges from the main server:
  35    * - @ref SM_PLAY
  36    * - @ref SM_PAUSE
  37    * - @ref SM_RESUME
  38    * - @ref SM_CANCEL
  39    * - @ref SM_RELOAD
  40    *
  41    * Messages from the speaker:
  42    * - @ref SM_PAUSED
  43    * - @ref SM_FINISHED
  44    * - @ref SM_PLAYING
  45    * - @ref SM_UNKNOWN
  46    * - @ref SM_ARRIVED
  47    */
  48   int type;
  49
  50   /** @brief Message-specific data */
  51   long data;
  52
  53   /** @brief Track ID (including 0 terminator) */
  54   char id[24];                          /* ID including terminator */
  55 };
  56
  57 /* messages from the main DisOrder server */
  58
  59 /** @brief Play track @c id
  60  *
  61  * The track must already have been prepared.
  62  */
  63 #define SM_PLAY 1
  64
  65 /** @brief Pause current track */
  66 #define SM_PAUSE 2
  67
  68 /** @brief Resume current track */
  69 #define SM_RESUME 3
  70
  71 /** @brief Cancel track @c id */
  72 #define SM_CANCEL 4
  73
  74 /** @brief Reload configuration */
  75 #define SM_RELOAD 5
  76
  77 /* messages from the speaker */
  78 /** @brief Paused track @c id, @c data seconds in
  79  *
  80  * There is no @c SM_RESUMED, instead @ref SM_PLAYING is sent after the track
  81  * starts playing again.
  82  */
  83 #define SM_PAUSED 128
  84
  85 /** @brief Finished playing track @c id */
  86 #define SM_FINISHED 129
  87
  88 /** @brief Never heard of track @c id */
  89 #define SM_UNKNOWN 130
  90
  91 /** @brief Currently track @c id, @c data seconds in
  92  *
  93  * This is sent from time to time while a track is playing.
  94  */
  95 #define SM_PLAYING 131
  96
  97 /** @brief Speaker process is ready
  98  *
  99  * This is sent once at startup when the speaker has finished its
 100  * initialization. */
 101 #define SM_READY 132
 102
 103 /** @brief Cancelled track @c id which wasn't playing */
 104 #define SM_STILLBORN 133
 105
 106 /** @brief A connection for track @c id arrived */
 107 #define SM_ARRIVED 134
 108
 109 void speaker_send(int fd, const struct speaker_message *sm);
 110 /* Send a message. */
 111
 112 int speaker_recv(int fd, struct speaker_message *sm);
 113 /* Receive a message.  Return 0 on EOF, +ve if a message is read, -1 on EAGAIN,
 114  * terminates on any other error. */
 115
 116 /** @brief One chunk in a stream */
 117 struct stream_header {
 118   /** @brief Number of bytes */
 119   uint32_t nbytes;
 120
 121   /** @brief Frames per second */
 122   uint32_t rate;
 123
 124   /** @brief Samples per frames */
 125   uint8_t channels;
 126
 127   /** @brief Bits per sample */
 128   uint8_t bits;
 129
 130   /** @brief Endianness */
 131   uint8_t endian;
 132 } attribute((packed));
 133
 134 static inline int formats_equal(const struct stream_header *a,
 135                                 const struct stream_header *b) {
 136   return (a->rate == b->rate
 137           && a->channels == b->channels
 138           && a->bits == b->bits
 139           && a->endian == b->endian);
 140 }
 141
 142 #endif /* SPEAKER_PROTOCOL_H */
 143
 144 /*
 145 Local Variables:
 146 c-basic-offset:2
 147 comment-column:40
 148 fill-column:79
 149 indent-tabs-mode:nil
 150 End:
 151 */