chiark / gitweb /
Fix a race between track startup and scratching. Basically if the
[disorder] / lib / speaker-protocol.h
CommitLineData
ea410ba1 1/*
2 * This file is part of DisOrder
3 * Copyright (C) 2005, 2007 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 2 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, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * 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, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
18 * USA
19 */
fbf86993 20/** @file lib/speaker-protocol.h
ea410ba1 21 * @brief Speaker/server protocol support
22 *
23 * This file defines the protocol by which the main server and the speaker
24 * process communicate.
25 */
26
cf714d85 27#ifndef SPEAKER_PROTOCOL_H
28#define SPEAKER_PROTOCOL_H
ea410ba1 29
30/** @brief A message from the main server to the speaker, or vica versa */
31struct speaker_message {
32 /** @brief Message type
33 *
34 * Messges from the main server:
ea410ba1 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
2b2a5fed 45 * - @ref SM_UNKNOWN
ea410ba1 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 */
ea410ba1 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
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87/** @brief Never heard of track @c id */
88#define SM_UNKNOWN 130
89
ea410ba1 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
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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
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102/** @brief Cancelled track @c id which wasn't playing */
103#define SM_STILLBORN 133
104
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105void speaker_send(int fd, const struct speaker_message *sm);
106/* Send a message. */
ea410ba1 107
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108int 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. */
ea410ba1 111
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112/** @brief One chunk in a stream */
113struct stream_header {
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114 /** @brief Number of bytes */
115 uint32_t nbytes;
116
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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#define ENDIAN_BIG 1
129#define ENDIAN_LITTLE 2
130#ifdef WORDS_BIGENDIAN
131# define ENDIAN_NATIVE ENDIAN_BIG
132#else
133# define ENDIAN_NATIVE ENDIAN_LITTLE
134#endif
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135} attribute((packed));
136
137static inline int formats_equal(const struct stream_header *a,
138 const struct stream_header *b) {
139 return (a->rate == b->rate
140 && a->channels == b->channels
141 && a->bits == b->bits
142 && a->endian == b->endian);
143}
144
cf714d85 145#endif /* SPEAKER_PROTOCOL_H */
ea410ba1 146
147/*
148Local Variables:
149c-basic-offset:2
150comment-column:40
151fill-column:79
152indent-tabs-mode:nil
153End:
154*/