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cf714d85 | 1 | /* |
2 | * This file is part of DisOrder | |
5aff007d | 3 | * Copyright (C) 2005-2008 Richard Kettlewell |
cf714d85 | 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 server/speaker.h | |
21 | * @brief Speaker process | |
22 | */ | |
23 | #ifndef SPEAKER_H | |
24 | #define SPEAKER_H | |
25 | ||
26 | #ifdef WORDS_BIGENDIAN | |
27 | # define MACHINE_AO_FMT AO_FMT_BIG | |
28 | #else | |
29 | # define MACHINE_AO_FMT AO_FMT_LITTLE | |
30 | #endif | |
31 | ||
5a7c42a8 | 32 | /** @brief Minimum number of frames to try to play at once |
cf714d85 | 33 | * |
5a7c42a8 | 34 | * The main loop will only attempt to play any audio when this many |
35 | * frames are available (or the current track has reached the end). | |
36 | * The actual number of frames it attempts to play will often be | |
37 | * larger than this (up to three times). | |
cf714d85 | 38 | * |
39 | * For ALSA we request a buffer of three times this size and set the low | |
40 | * watermark to this amount. The goal is then to keep between 1 and 3 times | |
41 | * this many frames in play. | |
42 | * | |
5a7c42a8 | 43 | * For other we attempt to play up to three times this many frames per |
cf714d85 | 44 | * shot. In practice we will often only send much less than this. |
45 | */ | |
46 | #define FRAMES 4096 | |
47 | ||
48 | /** @brief Bytes to send per network packet | |
a684c959 RK |
49 | * |
50 | * This is the maximum number of bytes we pass to write(2); to determine actual | |
51 | * packet sizes, add a UDP header and an IP header (and a link layer header if | |
52 | * it's the link layer size you care about). | |
cf714d85 | 53 | * |
54 | * Don't make this too big or arithmetic will start to overflow. | |
55 | */ | |
a684c959 | 56 | #define NETWORK_BYTES (1500-8/*UDP*/-40/*IP*/-8/*conservatism*/) |
cf714d85 | 57 | |
cf714d85 | 58 | /** @brief Maximum number of FDs to poll for */ |
59 | #define NFDS 256 | |
60 | ||
61 | /** @brief Track structure | |
62 | * | |
63 | * Known tracks are kept in a linked list. Usually there will be at most two | |
64 | * of these but rearranging the queue can cause there to be more. | |
65 | */ | |
66 | struct track { | |
6d2d327c RK |
67 | /** @brief Next track */ |
68 | struct track *next; | |
69 | ||
70 | /** @brief Input file descriptor */ | |
cf714d85 | 71 | int fd; /* input FD */ |
6d2d327c RK |
72 | |
73 | /** @brief Track ID */ | |
74 | char id[24]; | |
75 | ||
76 | /** @brief Start position of data in buffer */ | |
77 | size_t start; | |
78 | ||
79 | /** @brief Number of bytes of data in buffer */ | |
80 | size_t used; | |
81 | ||
82 | /** @brief Set @c fd is at EOF */ | |
83 | int eof; | |
84 | ||
85 | /** @brief Total number of frames played */ | |
86 | unsigned long long played; | |
87 | ||
88 | /** @brief Slot in @ref fds */ | |
89 | int slot; | |
90 | ||
f5a03f58 RK |
91 | /** @brief Set when playable |
92 | * | |
93 | * A track becomes playable whenever it fills its buffer or reaches EOF; it | |
94 | * stops being playable when it entirely empties its buffer. Tracks start | |
95 | * out life not playable. | |
96 | */ | |
97 | int playable; | |
98 | ||
6d2d327c RK |
99 | /** @brief Input buffer |
100 | * | |
101 | * 1Mbyte is enough for nearly 6s of 44100Hz 16-bit stereo | |
102 | */ | |
103 | char buffer[1048576]; | |
cf714d85 | 104 | }; |
105 | ||
106 | /** @brief Structure of a backend */ | |
107 | struct speaker_backend { | |
108 | /** @brief Which backend this is | |
109 | * | |
110 | * @c -1 terminates the list. | |
111 | */ | |
112 | int backend; | |
113 | ||
114 | /** @brief Flags | |
115 | * | |
6d2d327c | 116 | * This field is currently not used and must be 0. |
cf714d85 | 117 | */ |
118 | unsigned flags; | |
cf714d85 | 119 | |
120 | /** @brief Initialization | |
121 | * | |
122 | * Called once at startup. This is responsible for one-time setup | |
123 | * operations, for instance opening a network socket to transmit to. | |
124 | * | |
125 | * When writing to a native sound API this might @b not imply opening the | |
126 | * native sound device - that might be done by @c activate below. | |
127 | */ | |
128 | void (*init)(void); | |
129 | ||
130 | /** @brief Activation | |
131 | * @return 0 on success, non-0 on error | |
132 | * | |
133 | * Called to activate the output device. | |
134 | * | |
5a7c42a8 | 135 | * On input @ref device_state may be anything. If it is @ref |
136 | * device_open then the device is already open but might be using | |
137 | * the wrong sample format. The device should be reconfigured to | |
138 | * use the right sample format. | |
139 | * | |
140 | * If it is @ref device_error then a retry is underway and an | |
141 | * attempt to recover or re-open the device (with the right sample | |
142 | * format) should be made. | |
143 | * | |
144 | * If it is @ref device_closed then the device should be opened with | |
145 | * the right sample format. | |
146 | * | |
717ba987 RK |
147 | * Some devices are effectively always open and have no error state, in which |
148 | * case this callback can be NULL. Note that @ref device_state still | |
149 | * switches between @ref device_open and @ref device_closed in this case. | |
cf714d85 | 150 | */ |
5a7c42a8 | 151 | void (*activate)(void); |
cf714d85 | 152 | |
153 | /** @brief Play sound | |
154 | * @param frames Number of frames to play | |
155 | * @return Number of frames actually played | |
5a7c42a8 | 156 | * |
157 | * If an error occurs (and it is not immediately recovered) this | |
158 | * should set @ref device_state to @ref device_error. | |
cf714d85 | 159 | */ |
160 | size_t (*play)(size_t frames); | |
161 | ||
162 | /** @brief Deactivation | |
163 | * | |
5a7c42a8 | 164 | * Called to deactivate the sound device. This is the inverse of @c |
165 | * activate above. | |
166 | * | |
167 | * For sound devices that are open all the time and have no error | |
168 | * state, this callback can be NULL. Note that @ref device_state | |
0e4472a0 | 169 | * still switches between @ref device_open and @ref device_closed in |
5a7c42a8 | 170 | * this case. |
cf714d85 | 171 | */ |
172 | void (*deactivate)(void); | |
173 | ||
174 | /** @brief Called before poll() | |
e84fb5f0 | 175 | * @param timeoutp Pointer to timeout |
cf714d85 | 176 | * |
e84fb5f0 RK |
177 | * Called before the call to poll(). |
178 | * | |
179 | * If desirable, should call addfd() to update the FD array and stash the | |
180 | * slot number somewhere safe. This will only be called if @ref device_state | |
181 | * is @ref device_open. | |
182 | * | |
183 | * @p timeoutp points to the poll timeout value in milliseconds. It may be | |
184 | * reduced, but never increased. | |
23741390 RK |
185 | * |
186 | * NB you can NOT assume that @c beforepoll is always called before @c play. | |
cf714d85 | 187 | */ |
e84fb5f0 | 188 | void (*beforepoll)(int *timeoutp); |
cf714d85 | 189 | |
190 | /** @brief Called after poll() | |
5a7c42a8 | 191 | * @return 1 if output device ready for play, 0 otherwise |
cf714d85 | 192 | * |
5a7c42a8 | 193 | * Called after the call to poll(). This will only be called if |
194 | * @ref device_state = @ref device_open. | |
cf714d85 | 195 | * |
5a7c42a8 | 196 | * The return value should be 1 if the device was ready to play, or |
197 | * 0 if it was not. | |
cf714d85 | 198 | */ |
5a7c42a8 | 199 | int (*ready)(void); |
cf714d85 | 200 | }; |
201 | ||
5a7c42a8 | 202 | /** @brief Possible device states */ |
203 | enum device_states { | |
204 | /** @brief The device is closed */ | |
205 | device_closed, | |
206 | ||
207 | /** @brief The device is open and ready to receive sound | |
208 | * | |
209 | * The current device sample format is potentially part of this state. | |
210 | */ | |
211 | device_open, | |
212 | ||
213 | /** @brief An error has occurred on the device | |
214 | * | |
215 | * This state is used to ensure that a small interval is left | |
216 | * between retrying the device. If errors just set @ref | |
217 | * device_closed then the main loop would busy-wait on broken output | |
218 | * devices. | |
219 | * | |
220 | * The current device sample format is potentially part of this state. | |
221 | */ | |
222 | device_error | |
223 | }; | |
cf714d85 | 224 | |
5a7c42a8 | 225 | extern enum device_states device_state; |
5a7c42a8 | 226 | extern struct track *tracks; |
cf714d85 | 227 | extern struct track *playing; |
228 | ||
1c3f1e73 | 229 | extern const struct speaker_backend network_backend; |
230 | extern const struct speaker_backend alsa_backend; | |
231 | extern const struct speaker_backend command_backend; | |
937be4c0 | 232 | extern const struct speaker_backend coreaudio_backend; |
e99d42b1 | 233 | extern const struct speaker_backend oss_backend; |
1c3f1e73 | 234 | |
235 | extern struct pollfd fds[NFDS]; | |
236 | extern int fdno; | |
6d2d327c | 237 | extern size_t bpf; |
1c3f1e73 | 238 | extern int idled; |
239 | ||
240 | int addfd(int fd, int events); | |
1c3f1e73 | 241 | void abandon(void); |
242 | ||
cf714d85 | 243 | #endif /* SPEAKER_H */ |
244 | ||
245 | /* | |
246 | Local Variables: | |
247 | c-basic-offset:2 | |
248 | comment-column:40 | |
249 | fill-column:79 | |
250 | indent-tabs-mode:nil | |
251 | End: | |
252 | */ |