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19 #ifndef AVDEVICE_AVDEVICE_H
20 #define AVDEVICE_AVDEVICE_H
27 * Main libavdevice API header
31 * @defgroup lavd Special devices muxing/demuxing library
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.
41 * To use libavdevice, simply call avdevice_register_all() to register all
42 * compiled muxers and demuxers. They all use standard libavformat API.
46 #include "libavformat/avformat.h"
49 * Return the LIBAVDEVICE_VERSION_INT constant.
51 unsigned avdevice_version(void);
54 * Return the libavdevice build-time configuration.
56 const char *avdevice_configuration(void);
59 * Return the libavdevice license.
61 const char *avdevice_license(void);
64 * Initialize libavdevice and register all the input and output devices.
65 * @warning This function is not thread safe.
67 void avdevice_register_all(void);
70 * Audio input devices iterator.
72 * If d is NULL, returns the first registered input audio/video device,
73 * if d is non-NULL, returns the next registered input audio/video device after d
74 * or NULL if d is the last one.
76 AVInputFormat *av_input_audio_device_next(AVInputFormat *d);
79 * Video input devices iterator.
81 * If d is NULL, returns the first registered input audio/video device,
82 * if d is non-NULL, returns the next registered input audio/video device after d
83 * or NULL if d is the last one.
85 AVInputFormat *av_input_video_device_next(AVInputFormat *d);
88 * Audio output devices iterator.
90 * If d is NULL, returns the first registered output audio/video device,
91 * if d is non-NULL, returns the next registered output audio/video device after d
92 * or NULL if d is the last one.
94 AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
97 * Video output devices iterator.
99 * If d is NULL, returns the first registered output audio/video device,
100 * if d is non-NULL, returns the next registered output audio/video device after d
101 * or NULL if d is the last one.
103 AVOutputFormat *av_output_video_device_next(AVOutputFormat *d);
105 typedef struct AVDeviceRect {
106 int x; /**< x coordinate of top left corner */
107 int y; /**< y coordinate of top left corner */
108 int width; /**< width */
109 int height; /**< height */
113 * Message types used by avdevice_app_to_dev_control_message().
115 enum AVAppToDevMessageType {
119 AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'),
122 * Window size change message.
124 * Message is sent to the device every time the application changes the size
125 * of the window device renders to.
126 * Message should also be sent right after window is created.
128 * data: AVDeviceRect: new window size.
130 AV_APP_TO_DEV_WINDOW_SIZE = MKBETAG('G','E','O','M'),
133 * Repaint request message.
135 * Message is sent to the device when window have to be rapainted.
137 * data: AVDeviceRect: area required to be repainted.
138 * NULL: whole area is required to be repainted.
140 AV_APP_TO_DEV_WINDOW_REPAINT = MKBETAG('R','E','P','A')
144 * Message types used by avdevice_dev_to_app_control_message().
146 enum AVDevToAppMessageType {
150 AV_DEV_TO_APP_NONE = MKBETAG('N','O','N','E'),
153 * Create window buffer message.
155 * Device requests to create a window buffer. Exact meaning is device-
156 * and application-dependent. Message is sent before rendering first
157 * frame and all one-shot initializations should be done here.
158 * Application is allowed to ignore preferred window buffer size.
160 * @note: Application is obligated to inform about window buffer size
161 * with AV_APP_TO_DEV_WINDOW_SIZE message.
163 * data: AVDeviceRect: preferred size of the window buffer.
164 * NULL: no preferred size of the window buffer.
166 AV_DEV_TO_APP_CREATE_WINDOW_BUFFER = MKBETAG('B','C','R','E'),
169 * Prepare window buffer message.
171 * Device requests to prepare a window buffer for rendering.
172 * Exact meaning is device- and application-dependent.
173 * Message is sent before rendering of each frame.
177 AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER = MKBETAG('B','P','R','E'),
180 * Display window buffer message.
182 * Device requests to display a window buffer.
183 * Message is sent when new frame is ready to be displyed.
184 * Usually buffers need to be swapped in handler of this message.
188 AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER = MKBETAG('B','D','I','S'),
191 * Destroy window buffer message.
193 * Device requests to destroy a window buffer.
194 * Message is sent when device is about to be destroyed and window
195 * buffer is not required anymore.
199 AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER = MKBETAG('B','D','E','S')
203 * Send control message from application to device.
205 * @param s device context.
206 * @param type message type.
207 * @param data message data. Exact type depends on message type.
208 * @param data_size size of message data.
209 * @return >= 0 on success, negative on error.
210 * AVERROR(ENOSYS) when device doesn't implement handler of the message.
212 int avdevice_app_to_dev_control_message(struct AVFormatContext *s,
213 enum AVAppToDevMessageType type,
214 void *data, size_t data_size);
217 * Send control message from device to application.
219 * @param s device context.
220 * @param type message type.
221 * @param data message data. Can be NULL.
222 * @param data_size size of message data.
223 * @return >= 0 on success, negative on error.
224 * AVERROR(ENOSYS) when application doesn't implement handler of the message.
226 int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
227 enum AVDevToAppMessageType type,
228 void *data, size_t data_size);
231 * Structure describes basic parameters of the device.
233 typedef struct AVDeviceInfo {
234 char *device_name; /**< device name, format depends on device */
235 char *device_description; /**< human friendly name */
241 typedef struct AVDeviceInfoList {
242 AVDeviceInfo **devices; /**< list of autodetected devices */
243 int nb_devices; /**< number of autodetected devices */
244 int default_device; /**< index of default device or -1 if no default */
250 * Returns available device names and their parameters.
252 * @note: Some devices may accept system-dependent device names that cannot be
253 * autodetected. The list returned by this function cannot be assumed to
254 * be always completed.
256 * @param s device context.
257 * @param[out] device_list list of autodetected devices.
258 * @return count of autodetected devices, negative on error.
260 int avdevice_list_devices(struct AVFormatContext *s, AVDeviceInfoList **device_list);
263 * Convinient function to free result of avdevice_list_devices().
265 * @param devices device list to be freed.
267 void avdevice_free_list_devices(AVDeviceInfoList **device_list);
269 #endif /* AVDEVICE_AVDEVICE_H */