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