510 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			510 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #ifndef AVDEVICE_AVDEVICE_H
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| #define AVDEVICE_AVDEVICE_H
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| 
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| #include "version.h"
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| 
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| /**
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|  * @file
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|  * @ingroup lavd
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|  * Main libavdevice API header
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|  */
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| 
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| /**
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|  * @defgroup lavd Special devices muxing/demuxing library
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|  * @{
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|  * Libavdevice is a complementary library to @ref libavf "libavformat". It
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|  * provides various "special" platform-specific muxers and demuxers, e.g. for
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|  * grabbing devices, audio capture and playback etc. As a consequence, the
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|  * (de)muxers in libavdevice are of the AVFMT_NOFILE type (they use their own
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|  * I/O functions). The filename passed to avformat_open_input() often does not
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|  * refer to an actually existing file, but has some special device-specific
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|  * meaning - e.g. for x11grab it is the display name.
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|  *
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|  * To use libavdevice, simply call avdevice_register_all() to register all
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|  * compiled muxers and demuxers. They all use standard libavformat API.
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|  * @}
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|  */
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| 
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| #include "libavutil/log.h"
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| #include "libavutil/opt.h"
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| #include "libavutil/dict.h"
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| #include "libavformat/avformat.h"
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| 
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| /**
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|  * Return the LIBAVDEVICE_VERSION_INT constant.
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|  */
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| unsigned avdevice_version(void);
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| 
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| /**
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|  * Return the libavdevice build-time configuration.
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|  */
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| const char *avdevice_configuration(void);
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| 
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| /**
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|  * Return the libavdevice license.
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|  */
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| const char *avdevice_license(void);
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| 
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| /**
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|  * Initialize libavdevice and register all the input and output devices.
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|  * @warning This function is not thread safe.
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|  */
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| void avdevice_register_all(void);
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| 
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| /**
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|  * Audio input devices iterator.
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|  *
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|  * If d is NULL, returns the first registered input audio/video device,
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|  * if d is non-NULL, returns the next registered input audio/video device after d
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|  * or NULL if d is the last one.
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|  */
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| AVInputFormat *av_input_audio_device_next(AVInputFormat  *d);
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| 
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| /**
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|  * Video input devices iterator.
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|  *
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|  * If d is NULL, returns the first registered input audio/video device,
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|  * if d is non-NULL, returns the next registered input audio/video device after d
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|  * or NULL if d is the last one.
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|  */
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| AVInputFormat *av_input_video_device_next(AVInputFormat  *d);
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| 
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| /**
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|  * Audio output devices iterator.
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|  *
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|  * If d is NULL, returns the first registered output audio/video device,
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|  * if d is non-NULL, returns the next registered output audio/video device after d
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|  * or NULL if d is the last one.
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|  */
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| AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
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| 
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| /**
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|  * Video output devices iterator.
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|  *
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|  * If d is NULL, returns the first registered output audio/video device,
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|  * if d is non-NULL, returns the next registered output audio/video device after d
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|  * or NULL if d is the last one.
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|  */
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| AVOutputFormat *av_output_video_device_next(AVOutputFormat *d);
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| 
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| typedef struct AVDeviceRect {
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|     int x;      /**< x coordinate of top left corner */
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|     int y;      /**< y coordinate of top left corner */
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|     int width;  /**< width */
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|     int height; /**< height */
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| } AVDeviceRect;
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| 
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| /**
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|  * Message types used by avdevice_app_to_dev_control_message().
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|  */
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| enum AVAppToDevMessageType {
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|     /**
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|      * Dummy message.
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|      */
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|     AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'),
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| 
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|     /**
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|      * Window size change message.
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|      *
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|      * Message is sent to the device every time the application changes the size
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|      * of the window device renders to.
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|      * Message should also be sent right after window is created.
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|      *
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|      * data: AVDeviceRect: new window size.
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|      */
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|     AV_APP_TO_DEV_WINDOW_SIZE = MKBETAG('G','E','O','M'),
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| 
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|     /**
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|      * Repaint request message.
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|      *
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|      * Message is sent to the device when window has to be repainted.
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|      *
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|      * data: AVDeviceRect: area required to be repainted.
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|      *       NULL: whole area is required to be repainted.
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|      */
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|     AV_APP_TO_DEV_WINDOW_REPAINT = MKBETAG('R','E','P','A'),
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| 
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|     /**
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|      * Request pause/play.
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|      *
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|      * Application requests pause/unpause playback.
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|      * Mostly usable with devices that have internal buffer.
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|      * By default devices are not paused.
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|      *
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|      * data: NULL
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|      */
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|     AV_APP_TO_DEV_PAUSE        = MKBETAG('P', 'A', 'U', ' '),
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|     AV_APP_TO_DEV_PLAY         = MKBETAG('P', 'L', 'A', 'Y'),
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|     AV_APP_TO_DEV_TOGGLE_PAUSE = MKBETAG('P', 'A', 'U', 'T'),
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| 
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|     /**
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|      * Volume control message.
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|      *
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|      * Set volume level. It may be device-dependent if volume
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|      * is changed per stream or system wide. Per stream volume
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|      * change is expected when possible.
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|      *
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|      * data: double: new volume with range of 0.0 - 1.0.
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|      */
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|     AV_APP_TO_DEV_SET_VOLUME = MKBETAG('S', 'V', 'O', 'L'),
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| 
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|     /**
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|      * Mute control messages.
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|      *
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|      * Change mute state. It may be device-dependent if mute status
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|      * is changed per stream or system wide. Per stream mute status
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|      * change is expected when possible.
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|      *
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|      * data: NULL.
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|      */
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|     AV_APP_TO_DEV_MUTE        = MKBETAG(' ', 'M', 'U', 'T'),
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|     AV_APP_TO_DEV_UNMUTE      = MKBETAG('U', 'M', 'U', 'T'),
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|     AV_APP_TO_DEV_TOGGLE_MUTE = MKBETAG('T', 'M', 'U', 'T'),
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| 
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|     /**
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|      * Get volume/mute messages.
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|      *
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|      * Force the device to send AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED or
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|      * AV_DEV_TO_APP_MUTE_STATE_CHANGED command respectively.
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|      *
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|      * data: NULL.
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|      */
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|     AV_APP_TO_DEV_GET_VOLUME = MKBETAG('G', 'V', 'O', 'L'),
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|     AV_APP_TO_DEV_GET_MUTE   = MKBETAG('G', 'M', 'U', 'T'),
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| };
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| 
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| /**
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|  * Message types used by avdevice_dev_to_app_control_message().
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|  */
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| enum AVDevToAppMessageType {
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|     /**
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|      * Dummy message.
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|      */
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|     AV_DEV_TO_APP_NONE = MKBETAG('N','O','N','E'),
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| 
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|     /**
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|      * Create window buffer message.
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|      *
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|      * Device requests to create a window buffer. Exact meaning is device-
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|      * and application-dependent. Message is sent before rendering first
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|      * frame and all one-shot initializations should be done here.
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|      * Application is allowed to ignore preferred window buffer size.
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|      *
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|      * @note: Application is obligated to inform about window buffer size
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|      *        with AV_APP_TO_DEV_WINDOW_SIZE message.
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|      *
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|      * data: AVDeviceRect: preferred size of the window buffer.
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|      *       NULL: no preferred size of the window buffer.
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|      */
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|     AV_DEV_TO_APP_CREATE_WINDOW_BUFFER = MKBETAG('B','C','R','E'),
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| 
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|     /**
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|      * Prepare window buffer message.
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|      *
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|      * Device requests to prepare a window buffer for rendering.
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|      * Exact meaning is device- and application-dependent.
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|      * Message is sent before rendering of each frame.
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|      *
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|      * data: NULL.
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|      */
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|     AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER = MKBETAG('B','P','R','E'),
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| 
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|     /**
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|      * Display window buffer message.
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|      *
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|      * Device requests to display a window buffer.
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|      * Message is sent when new frame is ready to be displayed.
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|      * Usually buffers need to be swapped in handler of this message.
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|      *
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|      * data: NULL.
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|      */
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|     AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER = MKBETAG('B','D','I','S'),
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| 
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|     /**
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|      * Destroy window buffer message.
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|      *
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|      * Device requests to destroy a window buffer.
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|      * Message is sent when device is about to be destroyed and window
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|      * buffer is not required anymore.
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|      *
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|      * data: NULL.
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|      */
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|     AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER = MKBETAG('B','D','E','S'),
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| 
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|     /**
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|      * Buffer fullness status messages.
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|      *
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|      * Device signals buffer overflow/underflow.
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|      *
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|      * data: NULL.
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|      */
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|     AV_DEV_TO_APP_BUFFER_OVERFLOW = MKBETAG('B','O','F','L'),
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|     AV_DEV_TO_APP_BUFFER_UNDERFLOW = MKBETAG('B','U','F','L'),
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| 
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|     /**
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|      * Buffer readable/writable.
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|      *
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|      * Device informs that buffer is readable/writable.
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|      * When possible, device informs how many bytes can be read/write.
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|      *
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|      * @warning Device may not inform when number of bytes than can be read/write changes.
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|      *
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|      * data: int64_t: amount of bytes available to read/write.
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|      *       NULL: amount of bytes available to read/write is not known.
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|      */
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|     AV_DEV_TO_APP_BUFFER_READABLE = MKBETAG('B','R','D',' '),
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|     AV_DEV_TO_APP_BUFFER_WRITABLE = MKBETAG('B','W','R',' '),
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| 
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|     /**
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|      * Mute state change message.
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|      *
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|      * Device informs that mute state has changed.
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|      *
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|      * data: int: 0 for not muted state, non-zero for muted state.
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|      */
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|     AV_DEV_TO_APP_MUTE_STATE_CHANGED = MKBETAG('C','M','U','T'),
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| 
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|     /**
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|      * Volume level change message.
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|      *
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|      * Device informs that volume level has changed.
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|      *
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|      * data: double: new volume with range of 0.0 - 1.0.
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|      */
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|     AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED = MKBETAG('C','V','O','L'),
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| };
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| 
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| /**
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|  * Send control message from application to device.
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|  *
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|  * @param s         device context.
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|  * @param type      message type.
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|  * @param data      message data. Exact type depends on message type.
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|  * @param data_size size of message data.
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|  * @return >= 0 on success, negative on error.
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|  *         AVERROR(ENOSYS) when device doesn't implement handler of the message.
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|  */
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| int avdevice_app_to_dev_control_message(struct AVFormatContext *s,
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|                                         enum AVAppToDevMessageType type,
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|                                         void *data, size_t data_size);
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| 
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| /**
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|  * Send control message from device to application.
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|  *
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|  * @param s         device context.
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|  * @param type      message type.
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|  * @param data      message data. Can be NULL.
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|  * @param data_size size of message data.
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|  * @return >= 0 on success, negative on error.
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|  *         AVERROR(ENOSYS) when application doesn't implement handler of the message.
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|  */
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| int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
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|                                         enum AVDevToAppMessageType type,
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|                                         void *data, size_t data_size);
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| 
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| /**
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|  * Following API allows user to probe device capabilities (supported codecs,
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|  * pixel formats, sample formats, resolutions, channel counts, etc).
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|  * It is build on top op AVOption API.
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|  * Queried capabilities allows to set up converters of video or audio
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|  * parameters that fit to the device.
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|  *
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|  * List of capabilities that can be queried:
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|  *  - Capabilities valid for both audio and video devices:
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|  *    - codec:          supported audio/video codecs.
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|  *                      type: AV_OPT_TYPE_INT (AVCodecID value)
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|  *  - Capabilities valid for audio devices:
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|  *    - sample_format:  supported sample formats.
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|  *                      type: AV_OPT_TYPE_INT (AVSampleFormat value)
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|  *    - sample_rate:    supported sample rates.
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|  *                      type: AV_OPT_TYPE_INT
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|  *    - channels:       supported number of channels.
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|  *                      type: AV_OPT_TYPE_INT
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|  *    - channel_layout: supported channel layouts.
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|  *                      type: AV_OPT_TYPE_INT64
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|  *  - Capabilities valid for video devices:
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|  *    - pixel_format:   supported pixel formats.
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|  *                      type: AV_OPT_TYPE_INT (AVPixelFormat value)
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|  *    - window_size:    supported window sizes (describes size of the window size presented to the user).
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|  *                      type: AV_OPT_TYPE_IMAGE_SIZE
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|  *    - frame_size:     supported frame sizes (describes size of provided video frames).
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|  *                      type: AV_OPT_TYPE_IMAGE_SIZE
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|  *    - fps:            supported fps values
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|  *                      type: AV_OPT_TYPE_RATIONAL
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|  *
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|  * Value of the capability may be set by user using av_opt_set() function
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|  * and AVDeviceCapabilitiesQuery object. Following queries will
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|  * limit results to the values matching already set capabilities.
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|  * For example, setting a codec may impact number of formats or fps values
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|  * returned during next query. Setting invalid value may limit results to zero.
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|  *
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|  * Example of the usage basing on opengl output device:
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|  *
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|  * @code
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|  *  AVFormatContext *oc = NULL;
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|  *  AVDeviceCapabilitiesQuery *caps = NULL;
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|  *  AVOptionRanges *ranges;
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|  *  int ret;
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|  *
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|  *  if ((ret = avformat_alloc_output_context2(&oc, NULL, "opengl", NULL)) < 0)
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|  *      goto fail;
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|  *  if (avdevice_capabilities_create(&caps, oc, NULL) < 0)
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|  *      goto fail;
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|  *
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|  *  //query codecs
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|  *  if (av_opt_query_ranges(&ranges, caps, "codec", AV_OPT_MULTI_COMPONENT_RANGE)) < 0)
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|  *      goto fail;
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|  *  //pick codec here and set it
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|  *  av_opt_set(caps, "codec", AV_CODEC_ID_RAWVIDEO, 0);
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|  *
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|  *  //query format
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|  *  if (av_opt_query_ranges(&ranges, caps, "pixel_format", AV_OPT_MULTI_COMPONENT_RANGE)) < 0)
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|  *      goto fail;
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|  *  //pick format here and set it
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|  *  av_opt_set(caps, "pixel_format", AV_PIX_FMT_YUV420P, 0);
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|  *
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|  *  //query and set more capabilities
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|  *
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|  * fail:
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|  *  //clean up code
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|  *  avdevice_capabilities_free(&query, oc);
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|  *  avformat_free_context(oc);
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|  * @endcode
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|  */
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| 
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| /**
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|  * Structure describes device capabilities.
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|  *
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|  * It is used by devices in conjunction with av_device_capabilities AVOption table
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|  * to implement capabilities probing API based on AVOption API. Should not be used directly.
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|  */
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| typedef struct AVDeviceCapabilitiesQuery {
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|     const AVClass *av_class;
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|     AVFormatContext *device_context;
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|     enum AVCodecID codec;
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|     enum AVSampleFormat sample_format;
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|     enum AVPixelFormat pixel_format;
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|     int sample_rate;
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|     int channels;
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|     int64_t channel_layout;
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|     int window_width;
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|     int window_height;
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|     int frame_width;
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|     int frame_height;
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|     AVRational fps;
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| } AVDeviceCapabilitiesQuery;
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| 
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| /**
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|  * AVOption table used by devices to implement device capabilities API. Should not be used by a user.
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|  */
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| extern const AVOption av_device_capabilities[];
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| 
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| /**
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|  * Initialize capabilities probing API based on AVOption API.
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|  *
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|  * avdevice_capabilities_free() must be called when query capabilities API is
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|  * not used anymore.
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|  *
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|  * @param[out] caps      Device capabilities data. Pointer to a NULL pointer must be passed.
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|  * @param s              Context of the device.
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|  * @param device_options An AVDictionary filled with device-private options.
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|  *                       On return this parameter will be destroyed and replaced with a dict
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|  *                       containing options that were not found. May be NULL.
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|  *                       The same options must be passed later to avformat_write_header() for output
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|  *                       devices or avformat_open_input() for input devices, or at any other place
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|  *                       that affects device-private options.
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|  *
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|  * @return >= 0 on success, negative otherwise.
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|  */
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| int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s,
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|                                  AVDictionary **device_options);
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| 
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| /**
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|  * Free resources created by avdevice_capabilities_create()
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|  *
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|  * @param caps Device capabilities data to be freed.
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|  * @param s    Context of the device.
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|  */
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| void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s);
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| 
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| /**
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|  * Structure describes basic parameters of the device.
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|  */
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| typedef struct AVDeviceInfo {
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|     char *device_name;                   /**< device name, format depends on device */
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|     char *device_description;            /**< human friendly name */
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| } AVDeviceInfo;
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| 
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| /**
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|  * List of devices.
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|  */
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| typedef struct AVDeviceInfoList {
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|     AVDeviceInfo **devices;              /**< list of autodetected devices */
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|     int nb_devices;                      /**< number of autodetected devices */
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|     int default_device;                  /**< index of default device or -1 if no default */
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| } AVDeviceInfoList;
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| 
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| /**
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|  * List devices.
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|  *
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|  * Returns available device names and their parameters.
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|  *
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|  * @note: Some devices may accept system-dependent device names that cannot be
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|  *        autodetected. The list returned by this function cannot be assumed to
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|  *        be always completed.
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|  *
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|  * @param s                device context.
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|  * @param[out] device_list list of autodetected devices.
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|  * @return count of autodetected devices, negative on error.
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|  */
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| int avdevice_list_devices(struct AVFormatContext *s, AVDeviceInfoList **device_list);
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| 
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| /**
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|  * Convenient function to free result of avdevice_list_devices().
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|  *
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|  * @param devices device list to be freed.
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|  */
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| void avdevice_free_list_devices(AVDeviceInfoList **device_list);
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| 
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| /**
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|  * List devices.
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|  *
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|  * Returns available device names and their parameters.
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|  * These are convinient wrappers for avdevice_list_devices().
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|  * Device context is allocated and deallocated internally.
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|  *
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|  * @param device           device format. May be NULL if device name is set.
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|  * @param device_name      device name. May be NULL if device format is set.
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|  * @param device_options   An AVDictionary filled with device-private options. May be NULL.
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|  *                         The same options must be passed later to avformat_write_header() for output
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|  *                         devices or avformat_open_input() for input devices, or at any other place
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|  *                         that affects device-private options.
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|  * @param[out] device_list list of autodetected devices
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|  * @return count of autodetected devices, negative on error.
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|  * @note device argument takes precedence over device_name when both are set.
 | |
|  */
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| int avdevice_list_input_sources(struct AVInputFormat *device, const char *device_name,
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|                                 AVDictionary *device_options, AVDeviceInfoList **device_list);
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| int avdevice_list_output_sinks(struct AVOutputFormat *device, const char *device_name,
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|                                AVDictionary *device_options, AVDeviceInfoList **device_list);
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| 
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| #endif /* AVDEVICE_AVDEVICE_H */
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