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 Special devices muxing/demuxing library
32 * @{
33 * Libavdevice is a complementary library to @ref libavf "libavformat". It
34 * provides various "special" platform-specific muxers and demuxers, e.g. for
35 * grabbing devices, audio capture and playback etc. As a consequence, the
36 * (de)muxers in libavdevice are of the AVFMT_NOFILE type (they use their own
37 * I/O functions). The filename passed to avformat_open_input() often does not
38 * refer to an actually existing file, but has some special device-specific
39 * meaning - e.g. for x11grab it is the display name.
40 *
41 * To use libavdevice, simply call avdevice_register_all() to register all
42 * compiled muxers and demuxers. They all use standard libavformat API.
43 * @}
44 */
45
46#include "libavutil/log.h"
47#include "libavutil/opt.h"
48#include "libavutil/dict.h"
49#include "libavformat/avformat.h"
50
51/**
52 * Return the LIBAVDEVICE_VERSION_INT constant.
53 */
54unsigned avdevice_version(void);
55
56/**
57 * Return the libavdevice build-time configuration.
58 */
59const char *avdevice_configuration(void);
60
61/**
62 * Return the libavdevice license.
63 */
64const char *avdevice_license(void);
65
66/**
67 * Initialize libavdevice and register all the input and output devices.
68 * @warning This function is not thread safe.
69 */
70void avdevice_register_all(void);
71
72/**
73 * Audio input devices iterator.
74 *
75 * If d is NULL, returns the first registered input audio/video device,
76 * if d is non-NULL, returns the next registered input audio/video device after d
77 * or NULL if d is the last one.
78 */
79AVInputFormat *av_input_audio_device_next(AVInputFormat  *d);
80
81/**
82 * Video input devices iterator.
83 *
84 * If d is NULL, returns the first registered input audio/video device,
85 * if d is non-NULL, returns the next registered input audio/video device after d
86 * or NULL if d is the last one.
87 */
88AVInputFormat *av_input_video_device_next(AVInputFormat  *d);
89
90/**
91 * Audio output devices iterator.
92 *
93 * If d is NULL, returns the first registered output audio/video device,
94 * if d is non-NULL, returns the next registered output audio/video device after d
95 * or NULL if d is the last one.
96 */
97AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
98
99/**
100 * Video output devices iterator.
101 *
102 * If d is NULL, returns the first registered output audio/video device,
103 * if d is non-NULL, returns the next registered output audio/video device after d
104 * or NULL if d is the last one.
105 */
106AVOutputFormat *av_output_video_device_next(AVOutputFormat *d);
107
108typedef struct AVDeviceRect {
109    int x;      /**< x coordinate of top left corner */
110    int y;      /**< y coordinate of top left corner */
111    int width;  /**< width */
112    int height; /**< height */
113} AVDeviceRect;
114
115/**
116 * Message types used by avdevice_app_to_dev_control_message().
117 */
118enum AVAppToDevMessageType {
119    /**
120     * Dummy message.
121     */
122    AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'),
123
124    /**
125     * Window size change message.
126     *
127     * Message is sent to the device every time the application changes the size
128     * of the window device renders to.
129     * Message should also be sent right after window is created.
130     *
131     * data: AVDeviceRect: new window size.
132     */
133    AV_APP_TO_DEV_WINDOW_SIZE = MKBETAG('G','E','O','M'),
134
135    /**
136     * Repaint request message.
137     *
138     * Message is sent to the device when window has to be repainted.
139     *
140     * data: AVDeviceRect: area required to be repainted.
141     *       NULL: whole area is required to be repainted.
142     */
143    AV_APP_TO_DEV_WINDOW_REPAINT = MKBETAG('R','E','P','A'),
144
145    /**
146     * Request pause/play.
147     *
148     * Application requests pause/unpause playback.
149     * Mostly usable with devices that have internal buffer.
150     * By default devices are not paused.
151     *
152     * data: NULL
153     */
154    AV_APP_TO_DEV_PAUSE        = MKBETAG('P', 'A', 'U', ' '),
155    AV_APP_TO_DEV_PLAY         = MKBETAG('P', 'L', 'A', 'Y'),
156    AV_APP_TO_DEV_TOGGLE_PAUSE = MKBETAG('P', 'A', 'U', 'T'),
157
158    /**
159     * Volume control message.
160     *
161     * Set volume level. It may be device-dependent if volume
162     * is changed per stream or system wide. Per stream volume
163     * change is expected when possible.
164     *
165     * data: double: new volume with range of 0.0 - 1.0.
166     */
167    AV_APP_TO_DEV_SET_VOLUME = MKBETAG('S', 'V', 'O', 'L'),
168
169    /**
170     * Mute control messages.
171     *
172     * Change mute state. It may be device-dependent if mute status
173     * is changed per stream or system wide. Per stream mute status
174     * change is expected when possible.
175     *
176     * data: NULL.
177     */
178    AV_APP_TO_DEV_MUTE        = MKBETAG(' ', 'M', 'U', 'T'),
179    AV_APP_TO_DEV_UNMUTE      = MKBETAG('U', 'M', 'U', 'T'),
180    AV_APP_TO_DEV_TOGGLE_MUTE = MKBETAG('T', 'M', 'U', 'T'),
181
182    /**
183     * Get volume/mute messages.
184     *
185     * Force the device to send AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED or
186     * AV_DEV_TO_APP_MUTE_STATE_CHANGED command respectively.
187     *
188     * data: NULL.
189     */
190    AV_APP_TO_DEV_GET_VOLUME = MKBETAG('G', 'V', 'O', 'L'),
191    AV_APP_TO_DEV_GET_MUTE   = MKBETAG('G', 'M', 'U', 'T'),
192};
193
194/**
195 * Message types used by avdevice_dev_to_app_control_message().
196 */
197enum AVDevToAppMessageType {
198    /**
199     * Dummy message.
200     */
201    AV_DEV_TO_APP_NONE = MKBETAG('N','O','N','E'),
202
203    /**
204     * Create window buffer message.
205     *
206     * Device requests to create a window buffer. Exact meaning is device-
207     * and application-dependent. Message is sent before rendering first
208     * frame and all one-shot initializations should be done here.
209     * Application is allowed to ignore preferred window buffer size.
210     *
211     * @note: Application is obligated to inform about window buffer size
212     *        with AV_APP_TO_DEV_WINDOW_SIZE message.
213     *
214     * data: AVDeviceRect: preferred size of the window buffer.
215     *       NULL: no preferred size of the window buffer.
216     */
217    AV_DEV_TO_APP_CREATE_WINDOW_BUFFER = MKBETAG('B','C','R','E'),
218
219    /**
220     * Prepare window buffer message.
221     *
222     * Device requests to prepare a window buffer for rendering.
223     * Exact meaning is device- and application-dependent.
224     * Message is sent before rendering of each frame.
225     *
226     * data: NULL.
227     */
228    AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER = MKBETAG('B','P','R','E'),
229
230    /**
231     * Display window buffer message.
232     *
233     * Device requests to display a window buffer.
234     * Message is sent when new frame is ready to be displayed.
235     * Usually buffers need to be swapped in handler of this message.
236     *
237     * data: NULL.
238     */
239    AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER = MKBETAG('B','D','I','S'),
240
241    /**
242     * Destroy window buffer message.
243     *
244     * Device requests to destroy a window buffer.
245     * Message is sent when device is about to be destroyed and window
246     * buffer is not required anymore.
247     *
248     * data: NULL.
249     */
250    AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER = MKBETAG('B','D','E','S'),
251
252    /**
253     * Buffer fullness status messages.
254     *
255     * Device signals buffer overflow/underflow.
256     *
257     * data: NULL.
258     */
259    AV_DEV_TO_APP_BUFFER_OVERFLOW = MKBETAG('B','O','F','L'),
260    AV_DEV_TO_APP_BUFFER_UNDERFLOW = MKBETAG('B','U','F','L'),
261
262    /**
263     * Buffer readable/writable.
264     *
265     * Device informs that buffer is readable/writable.
266     * When possible, device informs how many bytes can be read/write.
267     *
268     * @warning Device may not inform when number of bytes than can be read/write changes.
269     *
270     * data: int64_t: amount of bytes available to read/write.
271     *       NULL: amount of bytes available to read/write is not known.
272     */
273    AV_DEV_TO_APP_BUFFER_READABLE = MKBETAG('B','R','D',' '),
274    AV_DEV_TO_APP_BUFFER_WRITABLE = MKBETAG('B','W','R',' '),
275
276    /**
277     * Mute state change message.
278     *
279     * Device informs that mute state has changed.
280     *
281     * data: int: 0 for not muted state, non-zero for muted state.
282     */
283    AV_DEV_TO_APP_MUTE_STATE_CHANGED = MKBETAG('C','M','U','T'),
284
285    /**
286     * Volume level change message.
287     *
288     * Device informs that volume level has changed.
289     *
290     * data: double: new volume with range of 0.0 - 1.0.
291     */
292    AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED = MKBETAG('C','V','O','L'),
293};
294
295/**
296 * Send control message from application to device.
297 *
298 * @param s         device context.
299 * @param type      message type.
300 * @param data      message data. Exact type depends on message type.
301 * @param data_size size of message data.
302 * @return >= 0 on success, negative on error.
303 *         AVERROR(ENOSYS) when device doesn't implement handler of the message.
304 */
305int avdevice_app_to_dev_control_message(struct AVFormatContext *s,
306                                        enum AVAppToDevMessageType type,
307                                        void *data, size_t data_size);
308
309/**
310 * Send control message from device to application.
311 *
312 * @param s         device context.
313 * @param type      message type.
314 * @param data      message data. Can be NULL.
315 * @param data_size size of message data.
316 * @return >= 0 on success, negative on error.
317 *         AVERROR(ENOSYS) when application doesn't implement handler of the message.
318 */
319int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
320                                        enum AVDevToAppMessageType type,
321                                        void *data, size_t data_size);
322
323/**
324 * Following API allows user to probe device capabilities (supported codecs,
325 * pixel formats, sample formats, resolutions, channel counts, etc).
326 * It is build on top op AVOption API.
327 * Queried capabilities allows to set up converters of video or audio
328 * parameters that fit to the device.
329 *
330 * List of capabilities that can be queried:
331 *  - Capabilities valid for both audio and video devices:
332 *    - codec:          supported audio/video codecs.
333 *                      type: AV_OPT_TYPE_INT (AVCodecID value)
334 *  - Capabilities valid for audio devices:
335 *    - sample_format:  supported sample formats.
336 *                      type: AV_OPT_TYPE_INT (AVSampleFormat value)
337 *    - sample_rate:    supported sample rates.
338 *                      type: AV_OPT_TYPE_INT
339 *    - channels:       supported number of channels.
340 *                      type: AV_OPT_TYPE_INT
341 *    - channel_layout: supported channel layouts.
342 *                      type: AV_OPT_TYPE_INT64
343 *  - Capabilities valid for video devices:
344 *    - pixel_format:   supported pixel formats.
345 *                      type: AV_OPT_TYPE_INT (AVPixelFormat value)
346 *    - window_size:    supported window sizes (describes size of the window size presented to the user).
347 *                      type: AV_OPT_TYPE_IMAGE_SIZE
348 *    - frame_size:     supported frame sizes (describes size of provided video frames).
349 *                      type: AV_OPT_TYPE_IMAGE_SIZE
350 *    - fps:            supported fps values
351 *                      type: AV_OPT_TYPE_RATIONAL
352 *
353 * Value of the capability may be set by user using av_opt_set() function
354 * and AVDeviceCapabilitiesQuery object. Following queries will
355 * limit results to the values matching already set capabilities.
356 * For example, setting a codec may impact number of formats or fps values
357 * returned during next query. Setting invalid value may limit results to zero.
358 *
359 * Example of the usage basing on opengl output device:
360 *
361 * @code
362 *  AVFormatContext *oc = NULL;
363 *  AVDeviceCapabilitiesQuery *caps = NULL;
364 *  AVOptionRanges *ranges;
365 *  int ret;
366 *
367 *  if ((ret = avformat_alloc_output_context2(&oc, NULL, "opengl", NULL)) < 0)
368 *      goto fail;
369 *  if (avdevice_capabilities_create(&caps, oc, NULL) < 0)
370 *      goto fail;
371 *
372 *  //query codecs
373 *  if (av_opt_query_ranges(&ranges, caps, "codec", AV_OPT_MULTI_COMPONENT_RANGE)) < 0)
374 *      goto fail;
375 *  //pick codec here and set it
376 *  av_opt_set(caps, "codec", AV_CODEC_ID_RAWVIDEO, 0);
377 *
378 *  //query format
379 *  if (av_opt_query_ranges(&ranges, caps, "pixel_format", AV_OPT_MULTI_COMPONENT_RANGE)) < 0)
380 *      goto fail;
381 *  //pick format here and set it
382 *  av_opt_set(caps, "pixel_format", AV_PIX_FMT_YUV420P, 0);
383 *
384 *  //query and set more capabilities
385 *
386 * fail:
387 *  //clean up code
388 *  avdevice_capabilities_free(&query, oc);
389 *  avformat_free_context(oc);
390 * @endcode
391 */
392
393/**
394 * Structure describes device capabilities.
395 *
396 * It is used by devices in conjunction with av_device_capabilities AVOption table
397 * to implement capabilities probing API based on AVOption API. Should not be used directly.
398 */
399typedef struct AVDeviceCapabilitiesQuery {
400    const AVClass *av_class;
401    AVFormatContext *device_context;
402    enum AVCodecID codec;
403    enum AVSampleFormat sample_format;
404    enum AVPixelFormat pixel_format;
405    int sample_rate;
406    int channels;
407    int64_t channel_layout;
408    int window_width;
409    int window_height;
410    int frame_width;
411    int frame_height;
412    AVRational fps;
413} AVDeviceCapabilitiesQuery;
414
415/**
416 * AVOption table used by devices to implement device capabilities API. Should not be used by a user.
417 */
418extern const AVOption av_device_capabilities[];
419
420/**
421 * Initialize capabilities probing API based on AVOption API.
422 *
423 * avdevice_capabilities_free() must be called when query capabilities API is
424 * not used anymore.
425 *
426 * @param[out] caps      Device capabilities data. Pointer to a NULL pointer must be passed.
427 * @param s              Context of the device.
428 * @param device_options An AVDictionary filled with device-private options.
429 *                       On return this parameter will be destroyed and replaced with a dict
430 *                       containing options that were not found. May be NULL.
431 *                       The same options must be passed later to avformat_write_header() for output
432 *                       devices or avformat_open_input() for input devices, or at any other place
433 *                       that affects device-private options.
434 *
435 * @return >= 0 on success, negative otherwise.
436 */
437int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s,
438                                 AVDictionary **device_options);
439
440/**
441 * Free resources created by avdevice_capabilities_create()
442 *
443 * @param caps Device capabilities data to be freed.
444 * @param s    Context of the device.
445 */
446void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s);
447
448/**
449 * Structure describes basic parameters of the device.
450 */
451typedef struct AVDeviceInfo {
452    char *device_name;                   /**< device name, format depends on device */
453    char *device_description;            /**< human friendly name */
454} AVDeviceInfo;
455
456/**
457 * List of devices.
458 */
459typedef struct AVDeviceInfoList {
460    AVDeviceInfo **devices;              /**< list of autodetected devices */
461    int nb_devices;                      /**< number of autodetected devices */
462    int default_device;                  /**< index of default device or -1 if no default */
463} AVDeviceInfoList;
464
465/**
466 * List devices.
467 *
468 * Returns available device names and their parameters.
469 *
470 * @note: Some devices may accept system-dependent device names that cannot be
471 *        autodetected. The list returned by this function cannot be assumed to
472 *        be always completed.
473 *
474 * @param s                device context.
475 * @param[out] device_list list of autodetected devices.
476 * @return count of autodetected devices, negative on error.
477 */
478int avdevice_list_devices(struct AVFormatContext *s, AVDeviceInfoList **device_list);
479
480/**
481 * Convenient function to free result of avdevice_list_devices().
482 *
483 * @param devices device list to be freed.
484 */
485void avdevice_free_list_devices(AVDeviceInfoList **device_list);
486
487#endif /* AVDEVICE_AVDEVICE_H */
488