| 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 | */ |
| 20 | /** @file lib/speaker-protocol.h |
| 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 | |
| 27 | #ifndef SPEAKER_PROTOCOL_H |
| 28 | #define SPEAKER_PROTOCOL_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 | */ |
| 46 | int type; |
| 47 | |
| 48 | /** @brief Message-specific data */ |
| 49 | long data; |
| 50 | |
| 51 | /** @brief Track ID (including 0 terminator) */ |
| 52 | char id[24]; /* ID including terminator */ |
| 53 | }; |
| 54 | |
| 55 | /* messages from the main DisOrder server */ |
| 56 | |
| 57 | /** @brief Play track @c id |
| 58 | * |
| 59 | * The track must already have been prepared. |
| 60 | */ |
| 61 | #define SM_PLAY 1 |
| 62 | |
| 63 | /** @brief Pause current track */ |
| 64 | #define SM_PAUSE 2 |
| 65 | |
| 66 | /** @brief Resume current track */ |
| 67 | #define SM_RESUME 3 |
| 68 | |
| 69 | /** @brief Cancel track @c id */ |
| 70 | #define SM_CANCEL 4 |
| 71 | |
| 72 | /** @brief Reload configuration */ |
| 73 | #define SM_RELOAD 5 |
| 74 | |
| 75 | /* messages from the speaker */ |
| 76 | /** @brief Paused track @c id, @c data seconds in |
| 77 | * |
| 78 | * There is no @c SM_RESUMED, instead @ref SM_PLAYING is sent after the track |
| 79 | * starts playing again. |
| 80 | */ |
| 81 | #define SM_PAUSED 128 |
| 82 | |
| 83 | /** @brief Finished playing track @c id */ |
| 84 | #define SM_FINISHED 129 |
| 85 | |
| 86 | /** @brief Currently track @c id, @c data seconds in |
| 87 | * |
| 88 | * This is sent from time to time while a track is playing. |
| 89 | */ |
| 90 | #define SM_PLAYING 131 |
| 91 | |
| 92 | /** @brief Speaker process is ready |
| 93 | * |
| 94 | * This is sent once at startup when the speaker has finished its |
| 95 | * initialization. */ |
| 96 | #define SM_READY 132 |
| 97 | |
| 98 | void speaker_send(int fd, const struct speaker_message *sm); |
| 99 | /* Send a message. */ |
| 100 | |
| 101 | int speaker_recv(int fd, struct speaker_message *sm); |
| 102 | /* Receive a message. Return 0 on EOF, +ve if a message is read, -1 on EAGAIN, |
| 103 | * terminates on any other error. */ |
| 104 | |
| 105 | /** @brief One chunk in a stream */ |
| 106 | struct stream_header { |
| 107 | /** @brief Number of bytes */ |
| 108 | uint32_t nbytes; |
| 109 | |
| 110 | /** @brief Frames per second */ |
| 111 | uint32_t rate; |
| 112 | |
| 113 | /** @brief Samples per frames */ |
| 114 | uint8_t channels; |
| 115 | |
| 116 | /** @brief Bits per sample */ |
| 117 | uint8_t bits; |
| 118 | |
| 119 | /** @brief Endianness */ |
| 120 | uint8_t endian; |
| 121 | #define ENDIAN_BIG 1 |
| 122 | #define ENDIAN_LITTLE 2 |
| 123 | #ifdef WORDS_BIGENDIAN |
| 124 | # define ENDIAN_NATIVE ENDIAN_BIG |
| 125 | #else |
| 126 | # define ENDIAN_NATIVE ENDIAN_LITTLE |
| 127 | #endif |
| 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 | */ |