2 * This file is part of DisOrder
3 * Copyright (C) 2005, 2007, 2008 Richard Kettlewell
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.
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.
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/>.
18 /** @file lib/speaker-protocol.h
19 * @brief Speaker/server protocol support
21 * This file defines the protocol by which the main server and the speaker
22 * process communicate.
25 #ifndef SPEAKER_PROTOCOL_H
26 #define SPEAKER_PROTOCOL_H
28 /** @brief A message from the main server to the speaker, or vica versa */
29 struct speaker_message {
30 /** @brief Message type
32 * Messges from the main server:
39 * Messages from the speaker:
47 /** @brief Message-specific data */
50 /** @brief Track ID (including 0 terminator) */
51 char id[24]; /* ID including terminator */
54 /* messages from the main DisOrder server */
56 /** @brief Play track @c id
58 * The track must already have been prepared.
62 /** @brief Pause current track */
65 /** @brief Resume current track */
68 /** @brief Cancel track @c id */
71 /** @brief Reload configuration */
74 /* messages from the speaker */
75 /** @brief Paused track @c id, @c data seconds in
77 * There is no @c SM_RESUMED, instead @ref SM_PLAYING is sent after the track
78 * starts playing again.
82 /** @brief Finished playing track @c id */
83 #define SM_FINISHED 129
85 /** @brief Never heard of track @c id */
86 #define SM_UNKNOWN 130
88 /** @brief Currently track @c id, @c data seconds in
90 * This is sent from time to time while a track is playing.
92 #define SM_PLAYING 131
94 /** @brief Speaker process is ready
96 * This is sent once at startup when the speaker has finished its
100 /** @brief Cancelled track @c id which wasn't playing */
101 #define SM_STILLBORN 133
103 void speaker_send(int fd, const struct speaker_message *sm);
104 /* Send a message. */
106 int speaker_recv(int fd, struct speaker_message *sm);
107 /* Receive a message. Return 0 on EOF, +ve if a message is read, -1 on EAGAIN,
108 * terminates on any other error. */
110 /** @brief One chunk in a stream */
111 struct stream_header {
112 /** @brief Number of bytes */
115 /** @brief Frames per second */
118 /** @brief Samples per frames */
121 /** @brief Bits per sample */
124 /** @brief Endianness */
127 #define ENDIAN_LITTLE 2
128 #ifdef WORDS_BIGENDIAN
129 # define ENDIAN_NATIVE ENDIAN_BIG
131 # define ENDIAN_NATIVE ENDIAN_LITTLE
133 } attribute((packed));
135 static inline int formats_equal(const struct stream_header *a,
136 const struct stream_header *b) {
137 return (a->rate == b->rate
138 && a->channels == b->channels
139 && a->bits == b->bits
140 && a->endian == b->endian);
143 #endif /* SPEAKER_PROTOCOL_H */