| 1 | /* |
| 2 | * This file is part of DisOrder. |
| 3 | * Copyright (C) 2009 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 | |
| 19 | /** @file lib/uaudio.h |
| 20 | * @brief Uniform audio interface |
| 21 | */ |
| 22 | |
| 23 | #ifndef UAUDIO_H |
| 24 | #define UAUDIO_H |
| 25 | |
| 26 | extern int uaudio_rate; |
| 27 | extern int uaudio_bits; |
| 28 | extern int uaudio_channels; |
| 29 | extern int uaudio_signed; |
| 30 | extern size_t uaudio_sample_size; |
| 31 | |
| 32 | /** @brief Callback to get audio data |
| 33 | * @param buffer Where to put audio data |
| 34 | * @param max_samples How many samples to supply |
| 35 | * @param userdata As passed to uaudio_open() |
| 36 | * @return Number of samples filled |
| 37 | * |
| 38 | * This function should not block if possible (better to fill the buffer with |
| 39 | * 0s) and should definitely not block indefinitely. This great caution with |
| 40 | * any locks or syscalls! In particular avoid it taking a lock that may be |
| 41 | * held while any of the @ref uaudio members are called. |
| 42 | * |
| 43 | * If it's more convenient, it's OK to return less than the maximum number of |
| 44 | * samples (including 0) provided you expect to be called again for more |
| 45 | * samples immediately. |
| 46 | */ |
| 47 | typedef size_t uaudio_callback(void *buffer, |
| 48 | size_t max_samples, |
| 49 | void *userdata); |
| 50 | |
| 51 | /** @brief Callback to play audio data |
| 52 | * @param buffer Pointer to audio buffer |
| 53 | * @param samples Number of samples to play |
| 54 | * @return Number of samples played |
| 55 | * |
| 56 | * Used with uaudio_thread_start() etc. |
| 57 | */ |
| 58 | typedef size_t uaudio_playcallback(void *buffer, size_t samples); |
| 59 | |
| 60 | /** @brief Audio API definition */ |
| 61 | struct uaudio { |
| 62 | /** @brief Name of this API */ |
| 63 | const char *name; |
| 64 | |
| 65 | /** @brief List of options, terminated by NULL */ |
| 66 | const char *const *options; |
| 67 | |
| 68 | /** @brief Do slow setup |
| 69 | * @param ua Handle returned by uaudio_open() |
| 70 | * @param callback Called for audio data |
| 71 | * @param userdata Passed to @p callback |
| 72 | * |
| 73 | * This does resource-intensive setup for the output device. |
| 74 | * |
| 75 | * For instance it might open mixable audio devices or network sockets. It |
| 76 | * will create any background thread required. However, it must not exclude |
| 77 | * other processes from outputting sound. |
| 78 | */ |
| 79 | void (*start)(uaudio_callback *callback, |
| 80 | void *userdata); |
| 81 | |
| 82 | /** @brief Tear down |
| 83 | * @param ua Handle returned by uaudio_open() |
| 84 | * |
| 85 | * This undoes the effect of @c start. |
| 86 | */ |
| 87 | void (*stop)(void); |
| 88 | |
| 89 | /** @brief Enable output |
| 90 | * |
| 91 | * A background thread will start calling @c callback as set by @c |
| 92 | * start and playing the audio data received from it. |
| 93 | */ |
| 94 | void (*activate)(void); |
| 95 | |
| 96 | /** @brief Disable output |
| 97 | * |
| 98 | * The background thread will stop calling @c callback. |
| 99 | */ |
| 100 | void (*deactivate)(void); |
| 101 | |
| 102 | /** @brief Open mixer device */ |
| 103 | void (*open_mixer)(void); |
| 104 | |
| 105 | /** @brief Closer mixer device */ |
| 106 | void (*close_mixer)(void); |
| 107 | |
| 108 | /** @brief Get volume |
| 109 | * @param left Where to put the left-channel value |
| 110 | * @param right Where to put the right-channel value |
| 111 | * |
| 112 | * 0 is silent and 100 is maximum volume. |
| 113 | */ |
| 114 | void (*get_volume)(int *left, int *right); |
| 115 | |
| 116 | /** @brief Set volume |
| 117 | * @param left Pointer to left-channel value (updated) |
| 118 | * @param right Pointer to right-channel value (updated) |
| 119 | * |
| 120 | * The values are updated with those actually set by the underlying system |
| 121 | * call. |
| 122 | * |
| 123 | * 0 is silent and 100 is maximum volume. |
| 124 | */ |
| 125 | void (*set_volume)(int *left, int *right); |
| 126 | |
| 127 | /** @brief Set configuration */ |
| 128 | void (*configure)(void); |
| 129 | |
| 130 | }; |
| 131 | |
| 132 | void uaudio_set_format(int rate, int channels, int samplesize, int signed_); |
| 133 | void uaudio_set(const char *name, const char *value); |
| 134 | char *uaudio_get(const char *name, const char *default_value); |
| 135 | void uaudio_thread_start(uaudio_callback *callback, |
| 136 | void *userdata, |
| 137 | uaudio_playcallback *playcallback, |
| 138 | size_t min, |
| 139 | size_t max, |
| 140 | unsigned flags); |
| 141 | |
| 142 | /** @brief Fake pauses |
| 143 | * |
| 144 | * This flag is used for audio backends that cannot sensibly be paused. |
| 145 | * The thread support code will supply silence while deactivated in this |
| 146 | * case. |
| 147 | */ |
| 148 | #define UAUDIO_THREAD_FAKE_PAUSE 0x00000001 |
| 149 | |
| 150 | void uaudio_thread_stop(void); |
| 151 | void uaudio_thread_activate(void); |
| 152 | void uaudio_thread_deactivate(void); |
| 153 | void uaudio_schedule_synchronize(void); |
| 154 | void uaudio_schedule_update(size_t written_samples); |
| 155 | void uaudio_schedule_init(void); |
| 156 | const struct uaudio *uaudio_find(const char *name); |
| 157 | |
| 158 | extern uint64_t uaudio_schedule_timestamp; |
| 159 | extern int uaudio_schedule_reactivated; |
| 160 | |
| 161 | #if HAVE_COREAUDIO_AUDIOHARDWARE_H |
| 162 | extern const struct uaudio uaudio_coreaudio; |
| 163 | #endif |
| 164 | |
| 165 | #if HAVE_ALSA_ASOUNDLIB_H |
| 166 | extern const struct uaudio uaudio_alsa; |
| 167 | #endif |
| 168 | |
| 169 | #if HAVE_SYS_SOUNDCARD_H || EMPEG_HOST |
| 170 | extern const struct uaudio uaudio_oss; |
| 171 | #endif |
| 172 | |
| 173 | extern const struct uaudio uaudio_rtp; |
| 174 | |
| 175 | extern const struct uaudio uaudio_command; |
| 176 | |
| 177 | extern const struct uaudio *const uaudio_apis[]; |
| 178 | |
| 179 | #endif /* UAUDIO_H */ |
| 180 | |
| 181 | /* |
| 182 | Local Variables: |
| 183 | c-basic-offset:2 |
| 184 | comment-column:40 |
| 185 | fill-column:79 |
| 186 | indent-tabs-mode:nil |
| 187 | End: |
| 188 | */ |