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, 2013 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 #if HAVE_NETINET_IN_H
  30 # include <netinet/in.h>
  31 #endif
  32
  33 /** @brief A message from the main server to the speaker, or vica versa */
  34 struct speaker_message {
  35   /** @brief Message type
  36    *
  37    * Messages from the main server:
  38    * - @ref SM_PLAY
  39    * - @ref SM_PAUSE
  40    * - @ref SM_RESUME
  41    * - @ref SM_CANCEL
  42    * - @ref SM_RELOAD
  43    * - @ref SM_RTP_REQUEST
  44    * - @ref SM_RTP_CANCEL
  45    *
  46    * Messages from the speaker:
  47    * - @ref SM_PAUSED
  48    * - @ref SM_FINISHED
  49    * - @ref SM_PLAYING
  50    * - @ref SM_UNKNOWN
  51    * - @ref SM_ARRIVED
  52    */
  53   int type;
  54
  55   /** @brief Message-specific data */
  56   long data;
  57
  58   union {
  59     /** @brief Track ID (including 0 terminator) */
  60     char id[24];                          /* ID including terminator */
  61
  62     /** @brief An IP address (for @ref SM_RTP_REQUEST and @ref SM_RTP_CANCEL) */
  63     struct sockaddr_storage address;
  64   } u;
  65 };
  66
  67 /* messages from the main DisOrder server */
  68
  69 /** @brief Play track @c id
  70  *
  71  * The track must already have been prepared.
  72  */
  73 #define SM_PLAY 1
  74
  75 /** @brief Pause current track */
  76 #define SM_PAUSE 2
  77
  78 /** @brief Resume current track */
  79 #define SM_RESUME 3
  80
  81 /** @brief Cancel track @c id */
  82 #define SM_CANCEL 4
  83
  84 /** @brief Reload configuration */
  85 #define SM_RELOAD 5
  86
  87 /** @brief Reload configuration */
  88 #define SM_RTP_REQUEST 6
  89
  90 /** @brief Reload configuration */
  91 #define SM_RTP_CANCEL 7
  92
  93 /* messages from the speaker */
  94 /** @brief Paused track @c id, @c data seconds in
  95  *
  96  * There is no @c SM_RESUMED, instead @ref SM_PLAYING is sent after the track
  97  * starts playing again.
  98  */
  99 #define SM_PAUSED 128
 100
 101 /** @brief Finished playing track @c id */
 102 #define SM_FINISHED 129
 103
 104 /** @brief Never heard of track @c id */
 105 #define SM_UNKNOWN 130
 106
 107 /** @brief Currently track @c id, @c data seconds in
 108  *
 109  * This is sent from time to time while a track is playing.
 110  */
 111 #define SM_PLAYING 131
 112
 113 /** @brief Speaker process is ready
 114  *
 115  * This is sent once at startup when the speaker has finished its
 116  * initialization. */
 117 #define SM_READY 132
 118
 119 /** @brief Cancelled track @c id which wasn't playing */
 120 #define SM_STILLBORN 133
 121
 122 /** @brief A connection for track @c id arrived */
 123 #define SM_ARRIVED 134
 124
 125 void speaker_send(int fd, const struct speaker_message *sm);
 126 /* Send a message. */
 127
 128 int speaker_recv(int fd, struct speaker_message *sm);
 129 /* Receive a message.  Return 0 on EOF, +ve if a message is read, -1 on EAGAIN,
 130  * terminates on any other error. */
 131
 132 /** @brief One chunk in a stream */
 133 struct stream_header {
 134   /** @brief Number of bytes */
 135   uint32_t nbytes;
 136
 137   /** @brief Frames per second */
 138   uint32_t rate;
 139
 140   /** @brief Samples per frames */
 141   uint8_t channels;
 142
 143   /** @brief Bits per sample */
 144   uint8_t bits;
 145
 146   /** @brief Endianness */
 147   uint8_t endian;
 148 } attribute((packed));
 149
 150 static inline int formats_equal(const struct stream_header *a,
 151                                 const struct stream_header *b) {
 152   return (a->rate == b->rate
 153           && a->channels == b->channels
 154           && a->bits == b->bits
 155           && a->endian == b->endian);
 156 }
 157
 158 #endif /* SPEAKER_PROTOCOL_H */
 159
 160 /*
 161 Local Variables:
 162 c-basic-offset:2
 163 comment-column:40
 164 fill-column:79
 165 indent-tabs-mode:nil
 166 End:
 167 */