1 /* 2 * This file is part of FFmpeg. 3 * 4 * FFmpeg is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * FFmpeg is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with FFmpeg; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19 #ifndef AVDEVICE_AVDEVICE_H 20 #define AVDEVICE_AVDEVICE_H 21 22 #include "version.h" 23 24 /** 25 * @file 26 * @ingroup lavd 27 * Main libavdevice API header 28 */ 29 30 /** 31 * @defgroup lavd libavdevice 32 * Special devices muxing/demuxing library. 33 * 34 * Libavdevice is a complementary library to @ref libavf "libavformat". It 35 * provides various "special" platform-specific muxers and demuxers, e.g. for 36 * grabbing devices, audio capture and playback etc. As a consequence, the 37 * (de)muxers in libavdevice are of the AVFMT_NOFILE type (they use their own 38 * I/O functions). The filename passed to avformat_open_input() often does not 39 * refer to an actually existing file, but has some special device-specific 40 * meaning - e.g. for xcbgrab it is the display name. 41 * 42 * To use libavdevice, simply call avdevice_register_all() to register all 43 * compiled muxers and demuxers. They all use standard libavformat API. 44 * 45 * @{ 46 */ 47 48 #include "libavutil/log.h" 49 #include "libavutil/opt.h" 50 #include "libavutil/dict.h" 51 #include "libavformat/avformat.h" 52 53 /** 54 * Return the LIBAVDEVICE_VERSION_INT constant. 55 */ 56 unsigned avdevice_version(void); 57 58 /** 59 * Return the libavdevice build-time configuration. 60 */ 61 const char *avdevice_configuration(void); 62 63 /** 64 * Return the libavdevice license. 65 */ 66 const char *avdevice_license(void); 67 68 /** 69 * Initialize libavdevice and register all the input and output devices. 70 */ 71 void avdevice_register_all(void); 72 73 /** 74 * Audio input devices iterator. 75 * 76 * If d is NULL, returns the first registered input audio/video device, 77 * if d is non-NULL, returns the next registered input audio/video device after d 78 * or NULL if d is the last one. 79 */ 80 AVInputFormat *av_input_audio_device_next(AVInputFormat *d); 81 82 /** 83 * Video input devices iterator. 84 * 85 * If d is NULL, returns the first registered input audio/video device, 86 * if d is non-NULL, returns the next registered input audio/video device after d 87 * or NULL if d is the last one. 88 */ 89 AVInputFormat *av_input_video_device_next(AVInputFormat *d); 90 91 /** 92 * Audio output devices iterator. 93 * 94 * If d is NULL, returns the first registered output audio/video device, 95 * if d is non-NULL, returns the next registered output audio/video device after d 96 * or NULL if d is the last one. 97 */ 98 AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d); 99 100 /** 101 * Video output devices iterator. 102 * 103 * If d is NULL, returns the first registered output audio/video device, 104 * if d is non-NULL, returns the next registered output audio/video device after d 105 * or NULL if d is the last one. 106 */ 107 AVOutputFormat *av_output_video_device_next(AVOutputFormat *d); 108 109 typedef struct AVDeviceRect { 110 int x; /**< x coordinate of top left corner */ 111 int y; /**< y coordinate of top left corner */ 112 int width; /**< width */ 113 int height; /**< height */ 114 } AVDeviceRect; 115 116 /** 117 * Message types used by avdevice_app_to_dev_control_message(). 118 */ 119 enum AVAppToDevMessageType { 120 /** 121 * Dummy message. 122 */ 123 AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'), 124 125 /** 126 * Window size change message. 127 * 128 * Message is sent to the device every time the application changes the size 129 * of the window device renders to. 130 * Message should also be sent right after window is created. 131 * 132 * data: AVDeviceRect: new window size. 133 */ 134 AV_APP_TO_DEV_WINDOW_SIZE = MKBETAG('G','E','O','M'), 135 136 /** 137 * Repaint request message. 138 * 139 * Message is sent to the device when window has to be repainted. 140 * 141 * data: AVDeviceRect: area required to be repainted. 142 * NULL: whole area is required to be repainted. 143 */ 144 AV_APP_TO_DEV_WINDOW_REPAINT = MKBETAG('R','E','P','A'), 145 146 /** 147 * Request pause/play. 148 * 149 * Application requests pause/unpause playback. 150 * Mostly usable with devices that have internal buffer. 151 * By default devices are not paused. 152 * 153 * data: NULL 154 */ 155 AV_APP_TO_DEV_PAUSE = MKBETAG('P', 'A', 'U', ' '), 156 AV_APP_TO_DEV_PLAY = MKBETAG('P', 'L', 'A', 'Y'), 157 AV_APP_TO_DEV_TOGGLE_PAUSE = MKBETAG('P', 'A', 'U', 'T'), 158 159 /** 160 * Volume control message. 161 * 162 * Set volume level. It may be device-dependent if volume 163 * is changed per stream or system wide. Per stream volume 164 * change is expected when possible. 165 * 166 * data: double: new volume with range of 0.0 - 1.0. 167 */ 168 AV_APP_TO_DEV_SET_VOLUME = MKBETAG('S', 'V', 'O', 'L'), 169 170 /** 171 * Mute control messages. 172 * 173 * Change mute state. It may be device-dependent if mute status 174 * is changed per stream or system wide. Per stream mute status 175 * change is expected when possible. 176 * 177 * data: NULL. 178 */ 179 AV_APP_TO_DEV_MUTE = MKBETAG(' ', 'M', 'U', 'T'), 180 AV_APP_TO_DEV_UNMUTE = MKBETAG('U', 'M', 'U', 'T'), 181 AV_APP_TO_DEV_TOGGLE_MUTE = MKBETAG('T', 'M', 'U', 'T'), 182 183 /** 184 * Get volume/mute messages. 185 * 186 * Force the device to send AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED or 187 * AV_DEV_TO_APP_MUTE_STATE_CHANGED command respectively. 188 * 189 * data: NULL. 190 */ 191 AV_APP_TO_DEV_GET_VOLUME = MKBETAG('G', 'V', 'O', 'L'), 192 AV_APP_TO_DEV_GET_MUTE = MKBETAG('G', 'M', 'U', 'T'), 193 }; 194 195 /** 196 * Message types used by avdevice_dev_to_app_control_message(). 197 */ 198 enum AVDevToAppMessageType { 199 /** 200 * Dummy message. 201 */ 202 AV_DEV_TO_APP_NONE = MKBETAG('N','O','N','E'), 203 204 /** 205 * Create window buffer message. 206 * 207 * Device requests to create a window buffer. Exact meaning is device- 208 * and application-dependent. Message is sent before rendering first 209 * frame and all one-shot initializations should be done here. 210 * Application is allowed to ignore preferred window buffer size. 211 * 212 * @note: Application is obligated to inform about window buffer size 213 * with AV_APP_TO_DEV_WINDOW_SIZE message. 214 * 215 * data: AVDeviceRect: preferred size of the window buffer. 216 * NULL: no preferred size of the window buffer. 217 */ 218 AV_DEV_TO_APP_CREATE_WINDOW_BUFFER = MKBETAG('B','C','R','E'), 219 220 /** 221 * Prepare window buffer message. 222 * 223 * Device requests to prepare a window buffer for rendering. 224 * Exact meaning is device- and application-dependent. 225 * Message is sent before rendering of each frame. 226 * 227 * data: NULL. 228 */ 229 AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER = MKBETAG('B','P','R','E'), 230 231 /** 232 * Display window buffer message. 233 * 234 * Device requests to display a window buffer. 235 * Message is sent when new frame is ready to be displayed. 236 * Usually buffers need to be swapped in handler of this message. 237 * 238 * data: NULL. 239 */ 240 AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER = MKBETAG('B','D','I','S'), 241 242 /** 243 * Destroy window buffer message. 244 * 245 * Device requests to destroy a window buffer. 246 * Message is sent when device is about to be destroyed and window 247 * buffer is not required anymore. 248 * 249 * data: NULL. 250 */ 251 AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER = MKBETAG('B','D','E','S'), 252 253 /** 254 * Buffer fullness status messages. 255 * 256 * Device signals buffer overflow/underflow. 257 * 258 * data: NULL. 259 */ 260 AV_DEV_TO_APP_BUFFER_OVERFLOW = MKBETAG('B','O','F','L'), 261 AV_DEV_TO_APP_BUFFER_UNDERFLOW = MKBETAG('B','U','F','L'), 262 263 /** 264 * Buffer readable/writable. 265 * 266 * Device informs that buffer is readable/writable. 267 * When possible, device informs how many bytes can be read/write. 268 * 269 * @warning Device may not inform when number of bytes than can be read/write changes. 270 * 271 * data: int64_t: amount of bytes available to read/write. 272 * NULL: amount of bytes available to read/write is not known. 273 */ 274 AV_DEV_TO_APP_BUFFER_READABLE = MKBETAG('B','R','D',' '), 275 AV_DEV_TO_APP_BUFFER_WRITABLE = MKBETAG('B','W','R',' '), 276 277 /** 278 * Mute state change message. 279 * 280 * Device informs that mute state has changed. 281 * 282 * data: int: 0 for not muted state, non-zero for muted state. 283 */ 284 AV_DEV_TO_APP_MUTE_STATE_CHANGED = MKBETAG('C','M','U','T'), 285 286 /** 287 * Volume level change message. 288 * 289 * Device informs that volume level has changed. 290 * 291 * data: double: new volume with range of 0.0 - 1.0. 292 */ 293 AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED = MKBETAG('C','V','O','L'), 294 }; 295 296 /** 297 * Send control message from application to device. 298 * 299 * @param s device context. 300 * @param type message type. 301 * @param data message data. Exact type depends on message type. 302 * @param data_size size of message data. 303 * @return >= 0 on success, negative on error. 304 * AVERROR(ENOSYS) when device doesn't implement handler of the message. 305 */ 306 int avdevice_app_to_dev_control_message(struct AVFormatContext *s, 307 enum AVAppToDevMessageType type, 308 void *data, size_t data_size); 309 310 /** 311 * Send control message from device to application. 312 * 313 * @param s device context. 314 * @param type message type. 315 * @param data message data. Can be NULL. 316 * @param data_size size of message data. 317 * @return >= 0 on success, negative on error. 318 * AVERROR(ENOSYS) when application doesn't implement handler of the message. 319 */ 320 int avdevice_dev_to_app_control_message(struct AVFormatContext *s, 321 enum AVDevToAppMessageType type, 322 void *data, size_t data_size); 323 324 #if FF_API_DEVICE_CAPABILITIES 325 /** 326 * Following API allows user to probe device capabilities (supported codecs, 327 * pixel formats, sample formats, resolutions, channel counts, etc). 328 * It is build on top op AVOption API. 329 * Queried capabilities make it possible to set up converters of video or audio 330 * parameters that fit to the device. 331 * 332 * List of capabilities that can be queried: 333 * - Capabilities valid for both audio and video devices: 334 * - codec: supported audio/video codecs. 335 * type: AV_OPT_TYPE_INT (AVCodecID value) 336 * - Capabilities valid for audio devices: 337 * - sample_format: supported sample formats. 338 * type: AV_OPT_TYPE_INT (AVSampleFormat value) 339 * - sample_rate: supported sample rates. 340 * type: AV_OPT_TYPE_INT 341 * - channels: supported number of channels. 342 * type: AV_OPT_TYPE_INT 343 * - channel_layout: supported channel layouts. 344 * type: AV_OPT_TYPE_INT64 345 * - Capabilities valid for video devices: 346 * - pixel_format: supported pixel formats. 347 * type: AV_OPT_TYPE_INT (AVPixelFormat value) 348 * - window_size: supported window sizes (describes size of the window size presented to the user). 349 * type: AV_OPT_TYPE_IMAGE_SIZE 350 * - frame_size: supported frame sizes (describes size of provided video frames). 351 * type: AV_OPT_TYPE_IMAGE_SIZE 352 * - fps: supported fps values 353 * type: AV_OPT_TYPE_RATIONAL 354 * 355 * Value of the capability may be set by user using av_opt_set() function 356 * and AVDeviceCapabilitiesQuery object. Following queries will 357 * limit results to the values matching already set capabilities. 358 * For example, setting a codec may impact number of formats or fps values 359 * returned during next query. Setting invalid value may limit results to zero. 360 * 361 * Example of the usage basing on opengl output device: 362 * 363 * @code 364 * AVFormatContext *oc = NULL; 365 * AVDeviceCapabilitiesQuery *caps = NULL; 366 * AVOptionRanges *ranges; 367 * int ret; 368 * 369 * if ((ret = avformat_alloc_output_context2(&oc, NULL, "opengl", NULL)) < 0) 370 * goto fail; 371 * if (avdevice_capabilities_create(&caps, oc, NULL) < 0) 372 * goto fail; 373 * 374 * //query codecs 375 * if (av_opt_query_ranges(&ranges, caps, "codec", AV_OPT_MULTI_COMPONENT_RANGE)) < 0) 376 * goto fail; 377 * //pick codec here and set it 378 * av_opt_set(caps, "codec", AV_CODEC_ID_RAWVIDEO, 0); 379 * 380 * //query format 381 * if (av_opt_query_ranges(&ranges, caps, "pixel_format", AV_OPT_MULTI_COMPONENT_RANGE)) < 0) 382 * goto fail; 383 * //pick format here and set it 384 * av_opt_set(caps, "pixel_format", AV_PIX_FMT_YUV420P, 0); 385 * 386 * //query and set more capabilities 387 * 388 * fail: 389 * //clean up code 390 * avdevice_capabilities_free(&query, oc); 391 * avformat_free_context(oc); 392 * @endcode 393 */ 394 395 /** 396 * Structure describes device capabilities. 397 * 398 * It is used by devices in conjunction with av_device_capabilities AVOption table 399 * to implement capabilities probing API based on AVOption API. Should not be used directly. 400 */ 401 typedef struct AVDeviceCapabilitiesQuery { 402 const AVClass *av_class; 403 AVFormatContext *device_context; 404 enum AVCodecID codec; 405 enum AVSampleFormat sample_format; 406 enum AVPixelFormat pixel_format; 407 int sample_rate; 408 int channels; 409 int64_t channel_layout; 410 int window_width; 411 int window_height; 412 int frame_width; 413 int frame_height; 414 AVRational fps; 415 } AVDeviceCapabilitiesQuery; 416 417 /** 418 * AVOption table used by devices to implement device capabilities API. Should not be used by a user. 419 */ 420 attribute_deprecated 421 extern const AVOption av_device_capabilities[]; 422 423 /** 424 * Initialize capabilities probing API based on AVOption API. 425 * 426 * avdevice_capabilities_free() must be called when query capabilities API is 427 * not used anymore. 428 * 429 * @param[out] caps Device capabilities data. Pointer to a NULL pointer must be passed. 430 * @param s Context of the device. 431 * @param device_options An AVDictionary filled with device-private options. 432 * On return this parameter will be destroyed and replaced with a dict 433 * containing options that were not found. May be NULL. 434 * The same options must be passed later to avformat_write_header() for output 435 * devices or avformat_open_input() for input devices, or at any other place 436 * that affects device-private options. 437 * 438 * @return >= 0 on success, negative otherwise. 439 */ 440 attribute_deprecated 441 int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s, 442 AVDictionary **device_options); 443 444 /** 445 * Free resources created by avdevice_capabilities_create() 446 * 447 * @param caps Device capabilities data to be freed. 448 * @param s Context of the device. 449 */ 450 attribute_deprecated 451 void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s); 452 #endif 453 454 /** 455 * Structure describes basic parameters of the device. 456 */ 457 typedef struct AVDeviceInfo { 458 char *device_name; /**< device name, format depends on device */ 459 char *device_description; /**< human friendly name */ 460 } AVDeviceInfo; 461 462 /** 463 * List of devices. 464 */ 465 typedef struct AVDeviceInfoList { 466 AVDeviceInfo **devices; /**< list of autodetected devices */ 467 int nb_devices; /**< number of autodetected devices */ 468 int default_device; /**< index of default device or -1 if no default */ 469 } AVDeviceInfoList; 470 471 /** 472 * List devices. 473 * 474 * Returns available device names and their parameters. 475 * 476 * @note: Some devices may accept system-dependent device names that cannot be 477 * autodetected. The list returned by this function cannot be assumed to 478 * be always completed. 479 * 480 * @param s device context. 481 * @param[out] device_list list of autodetected devices. 482 * @return count of autodetected devices, negative on error. 483 */ 484 int avdevice_list_devices(struct AVFormatContext *s, AVDeviceInfoList **device_list); 485 486 /** 487 * Convenient function to free result of avdevice_list_devices(). 488 * 489 * @param devices device list to be freed. 490 */ 491 void avdevice_free_list_devices(AVDeviceInfoList **device_list); 492 493 /** 494 * List devices. 495 * 496 * Returns available device names and their parameters. 497 * These are convinient wrappers for avdevice_list_devices(). 498 * Device context is allocated and deallocated internally. 499 * 500 * @param device device format. May be NULL if device name is set. 501 * @param device_name device name. May be NULL if device format is set. 502 * @param device_options An AVDictionary filled with device-private options. May be NULL. 503 * The same options must be passed later to avformat_write_header() for output 504 * devices or avformat_open_input() for input devices, or at any other place 505 * that affects device-private options. 506 * @param[out] device_list list of autodetected devices 507 * @return count of autodetected devices, negative on error. 508 * @note device argument takes precedence over device_name when both are set. 509 */ 510 int avdevice_list_input_sources(struct AVInputFormat *device, const char *device_name, 511 AVDictionary *device_options, AVDeviceInfoList **device_list); 512 int avdevice_list_output_sinks(struct AVOutputFormat *device, const char *device_name, 513 AVDictionary *device_options, AVDeviceInfoList **device_list); 514 515 /** 516 * @} 517 */ 518 519 #endif /* AVDEVICE_AVDEVICE_H */ 520