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42 
43 #ifndef OPENCV_VIDEOIO_HPP
44 #define OPENCV_VIDEOIO_HPP
45 
46 #include "opencv2/core.hpp"
47 
48 /**
49   @defgroup videoio Video I/O
50 
51   @brief Read and write video or images sequence with OpenCV
52 
53   ### See also:
54   - @ref videoio_overview
55   - Tutorials: @ref tutorial_table_of_content_videoio
56   @{
57     @defgroup videoio_flags_base Flags for video I/O
58     @defgroup videoio_flags_others Additional flags for video I/O API backends
59     @defgroup videoio_c C API for video I/O
60     @defgroup videoio_ios iOS glue for video I/O
61     @defgroup videoio_winrt WinRT glue for video I/O
62   @}
63 */
64 
65 ////////////////////////////////// video io /////////////////////////////////
66 
67 typedef struct CvCapture CvCapture;
68 typedef struct CvVideoWriter CvVideoWriter;
69 
70 namespace cv
71 {
72 
73 //! @addtogroup videoio
74 //! @{
75 
76 //! @addtogroup videoio_flags_base
77 //! @{
78 
79 
80 /** @brief %VideoCapture API backends identifier.
81 
82 Select preferred API for a capture object.
83 To be used in the VideoCapture::VideoCapture() constructor or VideoCapture::open()
84 
85 @note Backends are available only if they have been built with your OpenCV binaries.
86 See @ref videoio_overview for more information.
87 */
88 enum VideoCaptureAPIs {
89        CAP_ANY          = 0,            //!< Auto detect == 0
90        CAP_VFW          = 200,          //!< Video For Windows (platform native)
91        CAP_V4L          = 200,          //!< V4L/V4L2 capturing support via libv4l
92        CAP_V4L2         = CAP_V4L,      //!< Same as CAP_V4L
93        CAP_FIREWIRE     = 300,          //!< IEEE 1394 drivers
94        CAP_FIREWARE     = CAP_FIREWIRE, //!< Same as CAP_FIREWIRE
95        CAP_IEEE1394     = CAP_FIREWIRE, //!< Same as CAP_FIREWIRE
96        CAP_DC1394       = CAP_FIREWIRE, //!< Same as CAP_FIREWIRE
97        CAP_CMU1394      = CAP_FIREWIRE, //!< Same as CAP_FIREWIRE
98        CAP_QT           = 500,          //!< QuickTime
99        CAP_UNICAP       = 600,          //!< Unicap drivers
100        CAP_DSHOW        = 700,          //!< DirectShow (via videoInput)
101        CAP_PVAPI        = 800,          //!< PvAPI, Prosilica GigE SDK
102        CAP_OPENNI       = 900,          //!< OpenNI (for Kinect)
103        CAP_OPENNI_ASUS  = 910,          //!< OpenNI (for Asus Xtion)
104        CAP_ANDROID      = 1000,         //!< Android - not used
105        CAP_XIAPI        = 1100,         //!< XIMEA Camera API
106        CAP_AVFOUNDATION = 1200,         //!< AVFoundation framework for iOS (OS X Lion will have the same API)
107        CAP_GIGANETIX    = 1300,         //!< Smartek Giganetix GigEVisionSDK
108        CAP_MSMF         = 1400,         //!< Microsoft Media Foundation (via videoInput)
109        CAP_WINRT        = 1410,         //!< Microsoft Windows Runtime using Media Foundation
110        CAP_INTELPERC    = 1500,         //!< Intel Perceptual Computing SDK
111        CAP_OPENNI2      = 1600,         //!< OpenNI2 (for Kinect)
112        CAP_OPENNI2_ASUS = 1610,         //!< OpenNI2 (for Asus Xtion and Occipital Structure sensors)
113        CAP_GPHOTO2      = 1700,         //!< gPhoto2 connection
114        CAP_GSTREAMER    = 1800,         //!< GStreamer
115        CAP_FFMPEG       = 1900,         //!< Open and record video file or stream using the FFMPEG library
116        CAP_IMAGES       = 2000,         //!< OpenCV Image Sequence (e.g. img_%02d.jpg)
117        CAP_ARAVIS       = 2100,         //!< Aravis SDK
118        CAP_OPENCV_MJPEG = 2200,         //!< Built-in OpenCV MotionJPEG codec
119        CAP_INTEL_MFX    = 2300,         //!< Intel MediaSDK
120        CAP_XINE         = 2400,         //!< XINE engine (Linux)
121      };
122 
123 /** @brief %VideoCapture generic properties identifier.
124 
125  Reading / writing properties involves many layers. Some unexpected result might happens along this chain.
126  Effective behaviour depends from device hardware, driver and API Backend.
127  @sa videoio_flags_others, VideoCapture::get(), VideoCapture::set()
128 */
129 enum VideoCaptureProperties {
130        CAP_PROP_POS_MSEC       =0, //!< Current position of the video file in milliseconds.
131        CAP_PROP_POS_FRAMES     =1, //!< 0-based index of the frame to be decoded/captured next.
132        CAP_PROP_POS_AVI_RATIO  =2, //!< Relative position of the video file: 0=start of the film, 1=end of the film.
133        CAP_PROP_FRAME_WIDTH    =3, //!< Width of the frames in the video stream.
134        CAP_PROP_FRAME_HEIGHT   =4, //!< Height of the frames in the video stream.
135        CAP_PROP_FPS            =5, //!< Frame rate.
136        CAP_PROP_FOURCC         =6, //!< 4-character code of codec. see VideoWriter::fourcc .
137        CAP_PROP_FRAME_COUNT    =7, //!< Number of frames in the video file.
138        CAP_PROP_FORMAT         =8, //!< Format of the %Mat objects returned by VideoCapture::retrieve().
139        CAP_PROP_MODE           =9, //!< Backend-specific value indicating the current capture mode.
140        CAP_PROP_BRIGHTNESS    =10, //!< Brightness of the image (only for those cameras that support).
141        CAP_PROP_CONTRAST      =11, //!< Contrast of the image (only for cameras).
142        CAP_PROP_SATURATION    =12, //!< Saturation of the image (only for cameras).
143        CAP_PROP_HUE           =13, //!< Hue of the image (only for cameras).
144        CAP_PROP_GAIN          =14, //!< Gain of the image (only for those cameras that support).
145        CAP_PROP_EXPOSURE      =15, //!< Exposure (only for those cameras that support).
146        CAP_PROP_CONVERT_RGB   =16, //!< Boolean flags indicating whether images should be converted to RGB.
147        CAP_PROP_WHITE_BALANCE_BLUE_U =17, //!< Currently unsupported.
148        CAP_PROP_RECTIFICATION =18, //!< Rectification flag for stereo cameras (note: only supported by DC1394 v 2.x backend currently).
149        CAP_PROP_MONOCHROME    =19,
150        CAP_PROP_SHARPNESS     =20,
151        CAP_PROP_AUTO_EXPOSURE =21, //!< DC1394: exposure control done by camera, user can adjust reference level using this feature.
152        CAP_PROP_GAMMA         =22,
153        CAP_PROP_TEMPERATURE   =23,
154        CAP_PROP_TRIGGER       =24,
155        CAP_PROP_TRIGGER_DELAY =25,
156        CAP_PROP_WHITE_BALANCE_RED_V =26,
157        CAP_PROP_ZOOM          =27,
158        CAP_PROP_FOCUS         =28,
159        CAP_PROP_GUID          =29,
160        CAP_PROP_ISO_SPEED     =30,
161        CAP_PROP_BACKLIGHT     =32,
162        CAP_PROP_PAN           =33,
163        CAP_PROP_TILT          =34,
164        CAP_PROP_ROLL          =35,
165        CAP_PROP_IRIS          =36,
166        CAP_PROP_SETTINGS      =37, //!< Pop up video/camera filter dialog (note: only supported by DSHOW backend currently. The property value is ignored)
167        CAP_PROP_BUFFERSIZE    =38,
168        CAP_PROP_AUTOFOCUS     =39,
169        CAP_PROP_SAR_NUM       =40, //!< Sample aspect ratio: num/den (num)
170        CAP_PROP_SAR_DEN       =41, //!< Sample aspect ratio: num/den (den)
171 #ifndef CV_DOXYGEN
172        CV__CAP_PROP_LATEST
173 #endif
174      };
175 
176 
177 /** @brief Generic camera output modes identifier.
178 @note Currently, these are supported through the libv4l backend only.
179 */
180 enum VideoCaptureModes {
181        CAP_MODE_BGR  = 0, //!< BGR24 (default)
182        CAP_MODE_RGB  = 1, //!< RGB24
183        CAP_MODE_GRAY = 2, //!< Y8
184        CAP_MODE_YUYV = 3  //!< YUYV
185      };
186 
187 /** @brief %VideoWriter generic properties identifier.
188  @sa VideoWriter::get(), VideoWriter::set()
189 */
190 enum VideoWriterProperties {
191   VIDEOWRITER_PROP_QUALITY = 1,    //!< Current quality (0..100%) of the encoded videostream. Can be adjusted dynamically in some codecs.
192   VIDEOWRITER_PROP_FRAMEBYTES = 2, //!< (Read-only): Size of just encoded video frame. Note that the encoding order may be different from representation order.
193   VIDEOWRITER_PROP_NSTRIPES = 3    //!< Number of stripes for parallel encoding. -1 for auto detection.
194 };
195 
196 //! @} videoio_flags_base
197 
198 //! @addtogroup videoio_flags_others
199 //! @{
200 
201 /** @name IEEE 1394 drivers
202     @{
203 */
204 
205 /** @brief Modes of the IEEE 1394 controlling registers
206 (can be: auto, manual, auto single push, absolute Latter allowed with any other mode)
207 every feature can have only one mode turned on at a time
208 */
209 enum { CAP_PROP_DC1394_OFF                = -4, //!< turn the feature off (not controlled manually nor automatically).
210        CAP_PROP_DC1394_MODE_MANUAL        = -3, //!< set automatically when a value of the feature is set by the user.
211        CAP_PROP_DC1394_MODE_AUTO          = -2,
212        CAP_PROP_DC1394_MODE_ONE_PUSH_AUTO = -1,
213        CAP_PROP_DC1394_MAX                = 31
214      };
215 
216 //! @} IEEE 1394 drivers
217 
218 /** @name OpenNI (for Kinect)
219     @{
220 */
221 
222 //! OpenNI map generators
223 enum { CAP_OPENNI_DEPTH_GENERATOR = 1 << 31,
224        CAP_OPENNI_IMAGE_GENERATOR = 1 << 30,
225        CAP_OPENNI_IR_GENERATOR    = 1 << 29,
226        CAP_OPENNI_GENERATORS_MASK = CAP_OPENNI_DEPTH_GENERATOR + CAP_OPENNI_IMAGE_GENERATOR + CAP_OPENNI_IR_GENERATOR
227      };
228 
229 //! Properties of cameras available through OpenNI backend
230 enum { CAP_PROP_OPENNI_OUTPUT_MODE       = 100,
231        CAP_PROP_OPENNI_FRAME_MAX_DEPTH   = 101, //!< In mm
232        CAP_PROP_OPENNI_BASELINE          = 102, //!< In mm
233        CAP_PROP_OPENNI_FOCAL_LENGTH      = 103, //!< In pixels
234        CAP_PROP_OPENNI_REGISTRATION      = 104, //!< Flag that synchronizes the remapping depth map to image map
235                                                 //!< by changing depth generator's view point (if the flag is "on") or
236                                                 //!< sets this view point to its normal one (if the flag is "off").
237        CAP_PROP_OPENNI_REGISTRATION_ON   = CAP_PROP_OPENNI_REGISTRATION,
238        CAP_PROP_OPENNI_APPROX_FRAME_SYNC = 105,
239        CAP_PROP_OPENNI_MAX_BUFFER_SIZE   = 106,
240        CAP_PROP_OPENNI_CIRCLE_BUFFER     = 107,
241        CAP_PROP_OPENNI_MAX_TIME_DURATION = 108,
242        CAP_PROP_OPENNI_GENERATOR_PRESENT = 109,
243        CAP_PROP_OPENNI2_SYNC             = 110,
244        CAP_PROP_OPENNI2_MIRROR           = 111
245      };
246 
247 //! OpenNI shortcuts
248 enum { CAP_OPENNI_IMAGE_GENERATOR_PRESENT         = CAP_OPENNI_IMAGE_GENERATOR + CAP_PROP_OPENNI_GENERATOR_PRESENT,
249        CAP_OPENNI_IMAGE_GENERATOR_OUTPUT_MODE     = CAP_OPENNI_IMAGE_GENERATOR + CAP_PROP_OPENNI_OUTPUT_MODE,
250        CAP_OPENNI_DEPTH_GENERATOR_PRESENT         = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_GENERATOR_PRESENT,
251        CAP_OPENNI_DEPTH_GENERATOR_BASELINE        = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_BASELINE,
252        CAP_OPENNI_DEPTH_GENERATOR_FOCAL_LENGTH    = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_FOCAL_LENGTH,
253        CAP_OPENNI_DEPTH_GENERATOR_REGISTRATION    = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_REGISTRATION,
254        CAP_OPENNI_DEPTH_GENERATOR_REGISTRATION_ON = CAP_OPENNI_DEPTH_GENERATOR_REGISTRATION,
255        CAP_OPENNI_IR_GENERATOR_PRESENT            = CAP_OPENNI_IR_GENERATOR + CAP_PROP_OPENNI_GENERATOR_PRESENT,
256      };
257 
258 //! OpenNI data given from depth generator
259 enum { CAP_OPENNI_DEPTH_MAP         = 0, //!< Depth values in mm (CV_16UC1)
260        CAP_OPENNI_POINT_CLOUD_MAP   = 1, //!< XYZ in meters (CV_32FC3)
261        CAP_OPENNI_DISPARITY_MAP     = 2, //!< Disparity in pixels (CV_8UC1)
262        CAP_OPENNI_DISPARITY_MAP_32F = 3, //!< Disparity in pixels (CV_32FC1)
263        CAP_OPENNI_VALID_DEPTH_MASK  = 4, //!< CV_8UC1
264 
265        CAP_OPENNI_BGR_IMAGE         = 5, //!< Data given from RGB image generator
266        CAP_OPENNI_GRAY_IMAGE        = 6, //!< Data given from RGB image generator
267 
268        CAP_OPENNI_IR_IMAGE          = 7  //!< Data given from IR image generator
269      };
270 
271 //! Supported output modes of OpenNI image generator
272 enum { CAP_OPENNI_VGA_30HZ  = 0,
273        CAP_OPENNI_SXGA_15HZ = 1,
274        CAP_OPENNI_SXGA_30HZ = 2,
275        CAP_OPENNI_QVGA_30HZ = 3,
276        CAP_OPENNI_QVGA_60HZ = 4
277      };
278 
279 //! @} OpenNI
280 
281 /** @name GStreamer
282     @{
283 */
284 
285 enum { CAP_PROP_GSTREAMER_QUEUE_LENGTH = 200 //!< Default is 1
286      };
287 
288 //! @} GStreamer
289 
290 /** @name PvAPI, Prosilica GigE SDK
291     @{
292 */
293 
294 //! PVAPI
295 enum { CAP_PROP_PVAPI_MULTICASTIP           = 300, //!< IP for enable multicast master mode. 0 for disable multicast.
296        CAP_PROP_PVAPI_FRAMESTARTTRIGGERMODE = 301, //!< FrameStartTriggerMode: Determines how a frame is initiated.
297        CAP_PROP_PVAPI_DECIMATIONHORIZONTAL  = 302, //!< Horizontal sub-sampling of the image.
298        CAP_PROP_PVAPI_DECIMATIONVERTICAL    = 303, //!< Vertical sub-sampling of the image.
299        CAP_PROP_PVAPI_BINNINGX              = 304, //!< Horizontal binning factor.
300        CAP_PROP_PVAPI_BINNINGY              = 305, //!< Vertical binning factor.
301        CAP_PROP_PVAPI_PIXELFORMAT           = 306  //!< Pixel format.
302      };
303 
304 //! PVAPI: FrameStartTriggerMode
305 enum { CAP_PVAPI_FSTRIGMODE_FREERUN     = 0,    //!< Freerun
306        CAP_PVAPI_FSTRIGMODE_SYNCIN1     = 1,    //!< SyncIn1
307        CAP_PVAPI_FSTRIGMODE_SYNCIN2     = 2,    //!< SyncIn2
308        CAP_PVAPI_FSTRIGMODE_FIXEDRATE   = 3,    //!< FixedRate
309        CAP_PVAPI_FSTRIGMODE_SOFTWARE    = 4     //!< Software
310      };
311 
312 //! PVAPI: DecimationHorizontal, DecimationVertical
313 enum { CAP_PVAPI_DECIMATION_OFF       = 1,    //!< Off
314        CAP_PVAPI_DECIMATION_2OUTOF4   = 2,    //!< 2 out of 4 decimation
315        CAP_PVAPI_DECIMATION_2OUTOF8   = 4,    //!< 2 out of 8 decimation
316        CAP_PVAPI_DECIMATION_2OUTOF16  = 8     //!< 2 out of 16 decimation
317      };
318 
319 //! PVAPI: PixelFormat
320 enum { CAP_PVAPI_PIXELFORMAT_MONO8    = 1,    //!< Mono8
321        CAP_PVAPI_PIXELFORMAT_MONO16   = 2,    //!< Mono16
322        CAP_PVAPI_PIXELFORMAT_BAYER8   = 3,    //!< Bayer8
323        CAP_PVAPI_PIXELFORMAT_BAYER16  = 4,    //!< Bayer16
324        CAP_PVAPI_PIXELFORMAT_RGB24    = 5,    //!< Rgb24
325        CAP_PVAPI_PIXELFORMAT_BGR24    = 6,    //!< Bgr24
326        CAP_PVAPI_PIXELFORMAT_RGBA32   = 7,    //!< Rgba32
327        CAP_PVAPI_PIXELFORMAT_BGRA32   = 8,    //!< Bgra32
328      };
329 
330 //! @} PvAPI
331 
332 /** @name XIMEA Camera API
333     @{
334 */
335 
336 //! Properties of cameras available through XIMEA SDK backend
337 enum { CAP_PROP_XI_DOWNSAMPLING                                 = 400, //!< Change image resolution by binning or skipping.
338        CAP_PROP_XI_DATA_FORMAT                                  = 401, //!< Output data format.
339        CAP_PROP_XI_OFFSET_X                                     = 402, //!< Horizontal offset from the origin to the area of interest (in pixels).
340        CAP_PROP_XI_OFFSET_Y                                     = 403, //!< Vertical offset from the origin to the area of interest (in pixels).
341        CAP_PROP_XI_TRG_SOURCE                                   = 404, //!< Defines source of trigger.
342        CAP_PROP_XI_TRG_SOFTWARE                                 = 405, //!< Generates an internal trigger. PRM_TRG_SOURCE must be set to TRG_SOFTWARE.
343        CAP_PROP_XI_GPI_SELECTOR                                 = 406, //!< Selects general purpose input.
344        CAP_PROP_XI_GPI_MODE                                     = 407, //!< Set general purpose input mode.
345        CAP_PROP_XI_GPI_LEVEL                                    = 408, //!< Get general purpose level.
346        CAP_PROP_XI_GPO_SELECTOR                                 = 409, //!< Selects general purpose output.
347        CAP_PROP_XI_GPO_MODE                                     = 410, //!< Set general purpose output mode.
348        CAP_PROP_XI_LED_SELECTOR                                 = 411, //!< Selects camera signalling LED.
349        CAP_PROP_XI_LED_MODE                                     = 412, //!< Define camera signalling LED functionality.
350        CAP_PROP_XI_MANUAL_WB                                    = 413, //!< Calculates White Balance(must be called during acquisition).
351        CAP_PROP_XI_AUTO_WB                                      = 414, //!< Automatic white balance.
352        CAP_PROP_XI_AEAG                                         = 415, //!< Automatic exposure/gain.
353        CAP_PROP_XI_EXP_PRIORITY                                 = 416, //!< Exposure priority (0.5 - exposure 50%, gain 50%).
354        CAP_PROP_XI_AE_MAX_LIMIT                                 = 417, //!< Maximum limit of exposure in AEAG procedure.
355        CAP_PROP_XI_AG_MAX_LIMIT                                 = 418, //!< Maximum limit of gain in AEAG procedure.
356        CAP_PROP_XI_AEAG_LEVEL                                   = 419, //!< Average intensity of output signal AEAG should achieve(in %).
357        CAP_PROP_XI_TIMEOUT                                      = 420, //!< Image capture timeout in milliseconds.
358        CAP_PROP_XI_EXPOSURE                                     = 421, //!< Exposure time in microseconds.
359        CAP_PROP_XI_EXPOSURE_BURST_COUNT                         = 422, //!< Sets the number of times of exposure in one frame.
360        CAP_PROP_XI_GAIN_SELECTOR                                = 423, //!< Gain selector for parameter Gain allows to select different type of gains.
361        CAP_PROP_XI_GAIN                                         = 424, //!< Gain in dB.
362        CAP_PROP_XI_DOWNSAMPLING_TYPE                            = 426, //!< Change image downsampling type.
363        CAP_PROP_XI_BINNING_SELECTOR                             = 427, //!< Binning engine selector.
364        CAP_PROP_XI_BINNING_VERTICAL                             = 428, //!< Vertical Binning - number of vertical photo-sensitive cells to combine together.
365        CAP_PROP_XI_BINNING_HORIZONTAL                           = 429, //!< Horizontal Binning - number of horizontal photo-sensitive cells to combine together.
366        CAP_PROP_XI_BINNING_PATTERN                              = 430, //!< Binning pattern type.
367        CAP_PROP_XI_DECIMATION_SELECTOR                          = 431, //!< Decimation engine selector.
368        CAP_PROP_XI_DECIMATION_VERTICAL                          = 432, //!< Vertical Decimation - vertical sub-sampling of the image - reduces the vertical resolution of the image by the specified vertical decimation factor.
369        CAP_PROP_XI_DECIMATION_HORIZONTAL                        = 433, //!< Horizontal Decimation - horizontal sub-sampling of the image - reduces the horizontal resolution of the image by the specified vertical decimation factor.
370        CAP_PROP_XI_DECIMATION_PATTERN                           = 434, //!< Decimation pattern type.
371        CAP_PROP_XI_TEST_PATTERN_GENERATOR_SELECTOR              = 587, //!< Selects which test pattern generator is controlled by the TestPattern feature.
372        CAP_PROP_XI_TEST_PATTERN                                 = 588, //!< Selects which test pattern type is generated by the selected generator.
373        CAP_PROP_XI_IMAGE_DATA_FORMAT                            = 435, //!< Output data format.
374        CAP_PROP_XI_SHUTTER_TYPE                                 = 436, //!< Change sensor shutter type(CMOS sensor).
375        CAP_PROP_XI_SENSOR_TAPS                                  = 437, //!< Number of taps.
376        CAP_PROP_XI_AEAG_ROI_OFFSET_X                            = 439, //!< Automatic exposure/gain ROI offset X.
377        CAP_PROP_XI_AEAG_ROI_OFFSET_Y                            = 440, //!< Automatic exposure/gain ROI offset Y.
378        CAP_PROP_XI_AEAG_ROI_WIDTH                               = 441, //!< Automatic exposure/gain ROI Width.
379        CAP_PROP_XI_AEAG_ROI_HEIGHT                              = 442, //!< Automatic exposure/gain ROI Height.
380        CAP_PROP_XI_BPC                                          = 445, //!< Correction of bad pixels.
381        CAP_PROP_XI_WB_KR                                        = 448, //!< White balance red coefficient.
382        CAP_PROP_XI_WB_KG                                        = 449, //!< White balance green coefficient.
383        CAP_PROP_XI_WB_KB                                        = 450, //!< White balance blue coefficient.
384        CAP_PROP_XI_WIDTH                                        = 451, //!< Width of the Image provided by the device (in pixels).
385        CAP_PROP_XI_HEIGHT                                       = 452, //!< Height of the Image provided by the device (in pixels).
386        CAP_PROP_XI_REGION_SELECTOR                              = 589, //!< Selects Region in Multiple ROI which parameters are set by width, height, ... ,region mode.
387        CAP_PROP_XI_REGION_MODE                                  = 595, //!< Activates/deactivates Region selected by Region Selector.
388        CAP_PROP_XI_LIMIT_BANDWIDTH                              = 459, //!< Set/get bandwidth(datarate)(in Megabits).
389        CAP_PROP_XI_SENSOR_DATA_BIT_DEPTH                        = 460, //!< Sensor output data bit depth.
390        CAP_PROP_XI_OUTPUT_DATA_BIT_DEPTH                        = 461, //!< Device output data bit depth.
391        CAP_PROP_XI_IMAGE_DATA_BIT_DEPTH                         = 462, //!< bitdepth of data returned by function xiGetImage.
392        CAP_PROP_XI_OUTPUT_DATA_PACKING                          = 463, //!< Device output data packing (or grouping) enabled. Packing could be enabled if output_data_bit_depth > 8 and packing capability is available.
393        CAP_PROP_XI_OUTPUT_DATA_PACKING_TYPE                     = 464, //!< Data packing type. Some cameras supports only specific packing type.
394        CAP_PROP_XI_IS_COOLED                                    = 465, //!< Returns 1 for cameras that support cooling.
395        CAP_PROP_XI_COOLING                                      = 466, //!< Start camera cooling.
396        CAP_PROP_XI_TARGET_TEMP                                  = 467, //!< Set sensor target temperature for cooling.
397        CAP_PROP_XI_CHIP_TEMP                                    = 468, //!< Camera sensor temperature.
398        CAP_PROP_XI_HOUS_TEMP                                    = 469, //!< Camera housing temperature.
399        CAP_PROP_XI_HOUS_BACK_SIDE_TEMP                          = 590, //!< Camera housing back side temperature.
400        CAP_PROP_XI_SENSOR_BOARD_TEMP                            = 596, //!< Camera sensor board temperature.
401        CAP_PROP_XI_CMS                                          = 470, //!< Mode of color management system.
402        CAP_PROP_XI_APPLY_CMS                                    = 471, //!< Enable applying of CMS profiles to xiGetImage (see XI_PRM_INPUT_CMS_PROFILE, XI_PRM_OUTPUT_CMS_PROFILE).
403        CAP_PROP_XI_IMAGE_IS_COLOR                               = 474, //!< Returns 1 for color cameras.
404        CAP_PROP_XI_COLOR_FILTER_ARRAY                           = 475, //!< Returns color filter array type of RAW data.
405        CAP_PROP_XI_GAMMAY                                       = 476, //!< Luminosity gamma.
406        CAP_PROP_XI_GAMMAC                                       = 477, //!< Chromaticity gamma.
407        CAP_PROP_XI_SHARPNESS                                    = 478, //!< Sharpness Strength.
408        CAP_PROP_XI_CC_MATRIX_00                                 = 479, //!< Color Correction Matrix element [0][0].
409        CAP_PROP_XI_CC_MATRIX_01                                 = 480, //!< Color Correction Matrix element [0][1].
410        CAP_PROP_XI_CC_MATRIX_02                                 = 481, //!< Color Correction Matrix element [0][2].
411        CAP_PROP_XI_CC_MATRIX_03                                 = 482, //!< Color Correction Matrix element [0][3].
412        CAP_PROP_XI_CC_MATRIX_10                                 = 483, //!< Color Correction Matrix element [1][0].
413        CAP_PROP_XI_CC_MATRIX_11                                 = 484, //!< Color Correction Matrix element [1][1].
414        CAP_PROP_XI_CC_MATRIX_12                                 = 485, //!< Color Correction Matrix element [1][2].
415        CAP_PROP_XI_CC_MATRIX_13                                 = 486, //!< Color Correction Matrix element [1][3].
416        CAP_PROP_XI_CC_MATRIX_20                                 = 487, //!< Color Correction Matrix element [2][0].
417        CAP_PROP_XI_CC_MATRIX_21                                 = 488, //!< Color Correction Matrix element [2][1].
418        CAP_PROP_XI_CC_MATRIX_22                                 = 489, //!< Color Correction Matrix element [2][2].
419        CAP_PROP_XI_CC_MATRIX_23                                 = 490, //!< Color Correction Matrix element [2][3].
420        CAP_PROP_XI_CC_MATRIX_30                                 = 491, //!< Color Correction Matrix element [3][0].
421        CAP_PROP_XI_CC_MATRIX_31                                 = 492, //!< Color Correction Matrix element [3][1].
422        CAP_PROP_XI_CC_MATRIX_32                                 = 493, //!< Color Correction Matrix element [3][2].
423        CAP_PROP_XI_CC_MATRIX_33                                 = 494, //!< Color Correction Matrix element [3][3].
424        CAP_PROP_XI_DEFAULT_CC_MATRIX                            = 495, //!< Set default Color Correction Matrix.
425        CAP_PROP_XI_TRG_SELECTOR                                 = 498, //!< Selects the type of trigger.
426        CAP_PROP_XI_ACQ_FRAME_BURST_COUNT                        = 499, //!< Sets number of frames acquired by burst. This burst is used only if trigger is set to FrameBurstStart.
427        CAP_PROP_XI_DEBOUNCE_EN                                  = 507, //!< Enable/Disable debounce to selected GPI.
428        CAP_PROP_XI_DEBOUNCE_T0                                  = 508, //!< Debounce time (x * 10us).
429        CAP_PROP_XI_DEBOUNCE_T1                                  = 509, //!< Debounce time (x * 10us).
430        CAP_PROP_XI_DEBOUNCE_POL                                 = 510, //!< Debounce polarity (pol = 1 t0 - falling edge, t1 - rising edge).
431        CAP_PROP_XI_LENS_MODE                                    = 511, //!< Status of lens control interface. This shall be set to XI_ON before any Lens operations.
432        CAP_PROP_XI_LENS_APERTURE_VALUE                          = 512, //!< Current lens aperture value in stops. Examples: 2.8, 4, 5.6, 8, 11.
433        CAP_PROP_XI_LENS_FOCUS_MOVEMENT_VALUE                    = 513, //!< Lens current focus movement value to be used by XI_PRM_LENS_FOCUS_MOVE in motor steps.
434        CAP_PROP_XI_LENS_FOCUS_MOVE                              = 514, //!< Moves lens focus motor by steps set in XI_PRM_LENS_FOCUS_MOVEMENT_VALUE.
435        CAP_PROP_XI_LENS_FOCUS_DISTANCE                          = 515, //!< Lens focus distance in cm.
436        CAP_PROP_XI_LENS_FOCAL_LENGTH                            = 516, //!< Lens focal distance in mm.
437        CAP_PROP_XI_LENS_FEATURE_SELECTOR                        = 517, //!< Selects the current feature which is accessible by XI_PRM_LENS_FEATURE.
438        CAP_PROP_XI_LENS_FEATURE                                 = 518, //!< Allows access to lens feature value currently selected by XI_PRM_LENS_FEATURE_SELECTOR.
439        CAP_PROP_XI_DEVICE_MODEL_ID                              = 521, //!< Returns device model id.
440        CAP_PROP_XI_DEVICE_SN                                    = 522, //!< Returns device serial number.
441        CAP_PROP_XI_IMAGE_DATA_FORMAT_RGB32_ALPHA                = 529, //!< The alpha channel of RGB32 output image format.
442        CAP_PROP_XI_IMAGE_PAYLOAD_SIZE                           = 530, //!< Buffer size in bytes sufficient for output image returned by xiGetImage.
443        CAP_PROP_XI_TRANSPORT_PIXEL_FORMAT                       = 531, //!< Current format of pixels on transport layer.
444        CAP_PROP_XI_SENSOR_CLOCK_FREQ_HZ                         = 532, //!< Sensor clock frequency in Hz.
445        CAP_PROP_XI_SENSOR_CLOCK_FREQ_INDEX                      = 533, //!< Sensor clock frequency index. Sensor with selected frequencies have possibility to set the frequency only by this index.
446        CAP_PROP_XI_SENSOR_OUTPUT_CHANNEL_COUNT                  = 534, //!< Number of output channels from sensor used for data transfer.
447        CAP_PROP_XI_FRAMERATE                                    = 535, //!< Define framerate in Hz.
448        CAP_PROP_XI_COUNTER_SELECTOR                             = 536, //!< Select counter.
449        CAP_PROP_XI_COUNTER_VALUE                                = 537, //!< Counter status.
450        CAP_PROP_XI_ACQ_TIMING_MODE                              = 538, //!< Type of sensor frames timing.
451        CAP_PROP_XI_AVAILABLE_BANDWIDTH                          = 539, //!< Calculate and returns available interface bandwidth(int Megabits).
452        CAP_PROP_XI_BUFFER_POLICY                                = 540, //!< Data move policy.
453        CAP_PROP_XI_LUT_EN                                       = 541, //!< Activates LUT.
454        CAP_PROP_XI_LUT_INDEX                                    = 542, //!< Control the index (offset) of the coefficient to access in the LUT.
455        CAP_PROP_XI_LUT_VALUE                                    = 543, //!< Value at entry LUTIndex of the LUT.
456        CAP_PROP_XI_TRG_DELAY                                    = 544, //!< Specifies the delay in microseconds (us) to apply after the trigger reception before activating it.
457        CAP_PROP_XI_TS_RST_MODE                                  = 545, //!< Defines how time stamp reset engine will be armed.
458        CAP_PROP_XI_TS_RST_SOURCE                                = 546, //!< Defines which source will be used for timestamp reset. Writing this parameter will trigger settings of engine (arming).
459        CAP_PROP_XI_IS_DEVICE_EXIST                              = 547, //!< Returns 1 if camera connected and works properly.
460        CAP_PROP_XI_ACQ_BUFFER_SIZE                              = 548, //!< Acquisition buffer size in buffer_size_unit. Default bytes.
461        CAP_PROP_XI_ACQ_BUFFER_SIZE_UNIT                         = 549, //!< Acquisition buffer size unit in bytes. Default 1. E.g. Value 1024 means that buffer_size is in KiBytes.
462        CAP_PROP_XI_ACQ_TRANSPORT_BUFFER_SIZE                    = 550, //!< Acquisition transport buffer size in bytes.
463        CAP_PROP_XI_BUFFERS_QUEUE_SIZE                           = 551, //!< Queue of field/frame buffers.
464        CAP_PROP_XI_ACQ_TRANSPORT_BUFFER_COMMIT                  = 552, //!< Number of buffers to commit to low level.
465        CAP_PROP_XI_RECENT_FRAME                                 = 553, //!< GetImage returns most recent frame.
466        CAP_PROP_XI_DEVICE_RESET                                 = 554, //!< Resets the camera to default state.
467        CAP_PROP_XI_COLUMN_FPN_CORRECTION                        = 555, //!< Correction of column FPN.
468        CAP_PROP_XI_ROW_FPN_CORRECTION                           = 591, //!< Correction of row FPN.
469        CAP_PROP_XI_SENSOR_MODE                                  = 558, //!< Current sensor mode. Allows to select sensor mode by one integer. Setting of this parameter affects: image dimensions and downsampling.
470        CAP_PROP_XI_HDR                                          = 559, //!< Enable High Dynamic Range feature.
471        CAP_PROP_XI_HDR_KNEEPOINT_COUNT                          = 560, //!< The number of kneepoints in the PWLR.
472        CAP_PROP_XI_HDR_T1                                       = 561, //!< Position of first kneepoint(in % of XI_PRM_EXPOSURE).
473        CAP_PROP_XI_HDR_T2                                       = 562, //!< Position of second kneepoint (in % of XI_PRM_EXPOSURE).
474        CAP_PROP_XI_KNEEPOINT1                                   = 563, //!< Value of first kneepoint (% of sensor saturation).
475        CAP_PROP_XI_KNEEPOINT2                                   = 564, //!< Value of second kneepoint (% of sensor saturation).
476        CAP_PROP_XI_IMAGE_BLACK_LEVEL                            = 565, //!< Last image black level counts. Can be used for Offline processing to recall it.
477        CAP_PROP_XI_HW_REVISION                                  = 571, //!< Returns hardware revision number.
478        CAP_PROP_XI_DEBUG_LEVEL                                  = 572, //!< Set debug level.
479        CAP_PROP_XI_AUTO_BANDWIDTH_CALCULATION                   = 573, //!< Automatic bandwidth calculation.
480        CAP_PROP_XI_FFS_FILE_ID                                  = 594, //!< File number.
481        CAP_PROP_XI_FFS_FILE_SIZE                                = 580, //!< Size of file.
482        CAP_PROP_XI_FREE_FFS_SIZE                                = 581, //!< Size of free camera FFS.
483        CAP_PROP_XI_USED_FFS_SIZE                                = 582, //!< Size of used camera FFS.
484        CAP_PROP_XI_FFS_ACCESS_KEY                               = 583, //!< Setting of key enables file operations on some cameras.
485        CAP_PROP_XI_SENSOR_FEATURE_SELECTOR                      = 585, //!< Selects the current feature which is accessible by XI_PRM_SENSOR_FEATURE_VALUE.
486        CAP_PROP_XI_SENSOR_FEATURE_VALUE                         = 586, //!< Allows access to sensor feature value currently selected by XI_PRM_SENSOR_FEATURE_SELECTOR.
487      };
488 
489 //! @} XIMEA
490 
491 /** @name AVFoundation framework for iOS
492     OS X Lion will have the same API
493     @{
494 */
495 
496 //! Properties of cameras available through AVFOUNDATION backend
497 enum { CAP_PROP_IOS_DEVICE_FOCUS        = 9001,
498        CAP_PROP_IOS_DEVICE_EXPOSURE     = 9002,
499        CAP_PROP_IOS_DEVICE_FLASH        = 9003,
500        CAP_PROP_IOS_DEVICE_WHITEBALANCE = 9004,
501        CAP_PROP_IOS_DEVICE_TORCH        = 9005
502      };
503 
504 /** @name Smartek Giganetix GigEVisionSDK
505     @{
506 */
507 
508 //! Properties of cameras available through Smartek Giganetix Ethernet Vision backend
509 /* --- Vladimir Litvinenko (litvinenko.vladimir@gmail.com) --- */
510 enum { CAP_PROP_GIGA_FRAME_OFFSET_X   = 10001,
511        CAP_PROP_GIGA_FRAME_OFFSET_Y   = 10002,
512        CAP_PROP_GIGA_FRAME_WIDTH_MAX  = 10003,
513        CAP_PROP_GIGA_FRAME_HEIGH_MAX  = 10004,
514        CAP_PROP_GIGA_FRAME_SENS_WIDTH = 10005,
515        CAP_PROP_GIGA_FRAME_SENS_HEIGH = 10006
516      };
517 
518 //! @} Smartek
519 
520 /** @name Intel Perceptual Computing SDK
521     @{
522 */
523 enum { CAP_PROP_INTELPERC_PROFILE_COUNT               = 11001,
524        CAP_PROP_INTELPERC_PROFILE_IDX                 = 11002,
525        CAP_PROP_INTELPERC_DEPTH_LOW_CONFIDENCE_VALUE  = 11003,
526        CAP_PROP_INTELPERC_DEPTH_SATURATION_VALUE      = 11004,
527        CAP_PROP_INTELPERC_DEPTH_CONFIDENCE_THRESHOLD  = 11005,
528        CAP_PROP_INTELPERC_DEPTH_FOCAL_LENGTH_HORZ     = 11006,
529        CAP_PROP_INTELPERC_DEPTH_FOCAL_LENGTH_VERT     = 11007
530      };
531 
532 //! Intel Perceptual Streams
533 enum { CAP_INTELPERC_DEPTH_GENERATOR = 1 << 29,
534        CAP_INTELPERC_IMAGE_GENERATOR = 1 << 28,
535        CAP_INTELPERC_GENERATORS_MASK = CAP_INTELPERC_DEPTH_GENERATOR + CAP_INTELPERC_IMAGE_GENERATOR
536      };
537 
538 enum { CAP_INTELPERC_DEPTH_MAP              = 0, //!< Each pixel is a 16-bit integer. The value indicates the distance from an object to the camera's XY plane or the Cartesian depth.
539        CAP_INTELPERC_UVDEPTH_MAP            = 1, //!< Each pixel contains two 32-bit floating point values in the range of 0-1, representing the mapping of depth coordinates to the color coordinates.
540        CAP_INTELPERC_IR_MAP                 = 2, //!< Each pixel is a 16-bit integer. The value indicates the intensity of the reflected laser beam.
541        CAP_INTELPERC_IMAGE                  = 3
542      };
543 
544 //! @} Intel Perceptual
545 
546 /** @name gPhoto2 connection
547     @{
548 */
549 
550 /** @brief gPhoto2 properties
551 
552 If `propertyId` is less than 0 then work on widget with that __additive inversed__ camera setting ID
553 Get IDs by using CAP_PROP_GPHOTO2_WIDGET_ENUMERATE.
554 @see CvCaptureCAM_GPHOTO2 for more info
555 */
556 enum { CAP_PROP_GPHOTO2_PREVIEW           = 17001, //!< Capture only preview from liveview mode.
557        CAP_PROP_GPHOTO2_WIDGET_ENUMERATE  = 17002, //!< Readonly, returns (const char *).
558        CAP_PROP_GPHOTO2_RELOAD_CONFIG     = 17003, //!< Trigger, only by set. Reload camera settings.
559        CAP_PROP_GPHOTO2_RELOAD_ON_CHANGE  = 17004, //!< Reload all settings on set.
560        CAP_PROP_GPHOTO2_COLLECT_MSGS      = 17005, //!< Collect messages with details.
561        CAP_PROP_GPHOTO2_FLUSH_MSGS        = 17006, //!< Readonly, returns (const char *).
562        CAP_PROP_SPEED                     = 17007, //!< Exposure speed. Can be readonly, depends on camera program.
563        CAP_PROP_APERTURE                  = 17008, //!< Aperture. Can be readonly, depends on camera program.
564        CAP_PROP_EXPOSUREPROGRAM           = 17009, //!< Camera exposure program.
565        CAP_PROP_VIEWFINDER                = 17010  //!< Enter liveview mode.
566      };
567 
568 //! @} gPhoto2
569 
570 
571 /** @name Images backend
572     @{
573 */
574 
575 /** @brief Images backend properties
576 
577 */
578 enum { CAP_PROP_IMAGES_BASE = 18000,
579        CAP_PROP_IMAGES_LAST = 19000 // excluding
580      };
581 
582 //! @} Images
583 
584 //! @} videoio_flags_others
585 
586 
587 class IVideoCapture;
588 
589 /** @brief Class for video capturing from video files, image sequences or cameras.
590 
591 The class provides C++ API for capturing video from cameras or for reading video files and image sequences.
592 
593 Here is how the class can be used:
594 @include samples/cpp/videocapture_basic.cpp
595 
596 @note In @ref videoio_c "C API" the black-box structure `CvCapture` is used instead of %VideoCapture.
597 @note
598 -   (C++) A basic sample on using the %VideoCapture interface can be found at
599     `OPENCV_SOURCE_CODE/samples/cpp/videocapture_starter.cpp`
600 -   (Python) A basic sample on using the %VideoCapture interface can be found at
601     `OPENCV_SOURCE_CODE/samples/python/video.py`
602 -   (Python) A multi threaded video processing sample can be found at
603     `OPENCV_SOURCE_CODE/samples/python/video_threaded.py`
604 -   (Python) %VideoCapture sample showcasing some features of the Video4Linux2 backend
605     `OPENCV_SOURCE_CODE/samples/python/video_v4l2.py`
606  */
607 class CV_EXPORTS_W VideoCapture
608 {
609 public:
610     /** @brief Default constructor
611     @note In @ref videoio_c "C API", when you finished working with video, release CvCapture structure with
612     cvReleaseCapture(), or use Ptr\<CvCapture\> that calls cvReleaseCapture() automatically in the
613     destructor.
614      */
615     CV_WRAP VideoCapture();
616 
617     /** @overload
618     @brief  Open video file or a capturing device or a IP video stream for video capturing
619 
620     Same as VideoCapture(const String& filename, int apiPreference) but using default Capture API backends
621     */
622     CV_WRAP VideoCapture(const String& filename);
623 
624     /** @overload
625     @brief  Open video file or a capturing device or a IP video stream for video capturing with API Preference
626 
627     @param filename it can be:
628     - name of video file (eg. `video.avi`)
629     - or image sequence (eg. `img_%02d.jpg`, which will read samples like `img_00.jpg, img_01.jpg, img_02.jpg, ...`)
630     - or URL of video stream (eg. `protocol://host:port/script_name?script_params|auth`).
631       Note that each video stream or IP camera feed has its own URL scheme. Please refer to the
632       documentation of source stream to know the right URL.
633     @param apiPreference preferred Capture API backends to use. Can be used to enforce a specific reader
634     implementation if multiple are available: e.g. cv::CAP_FFMPEG or cv::CAP_IMAGES or cv::CAP_DSHOW.
635     @sa The list of supported API backends cv::VideoCaptureAPIs
636     */
637     CV_WRAP VideoCapture(const String& filename, int apiPreference);
638 
639     /** @overload
640     @brief  Open a camera for video capturing
641 
642     @param index camera_id + domain_offset (CAP_*) id of the video capturing device to open. To open default camera using default backend just pass 0.
643     Use a `domain_offset` to enforce a specific reader implementation if multiple are available like cv::CAP_FFMPEG or cv::CAP_IMAGES or cv::CAP_DSHOW.
644     e.g. to open Camera 1 using the MS Media Foundation API use `index = 1 + cv::CAP_MSMF`
645 
646     @sa The list of supported API backends cv::VideoCaptureAPIs
647     */
648     CV_WRAP VideoCapture(int index);
649 
650     /** @brief Default destructor
651 
652     The method first calls VideoCapture::release to close the already opened file or camera.
653     */
654     virtual ~VideoCapture();
655 
656     /** @brief  Open video file or a capturing device or a IP video stream for video capturing
657 
658     @overload
659 
660     Parameters are same as the constructor VideoCapture(const String& filename)
661     @return `true` if the file has been successfully opened
662 
663     The method first calls VideoCapture::release to close the already opened file or camera.
664      */
665     CV_WRAP virtual bool open(const String& filename);
666 
667     /** @brief  Open a camera for video capturing
668 
669     @overload
670 
671     Parameters are same as the constructor VideoCapture(int index)
672     @return `true` if the camera has been successfully opened.
673 
674     The method first calls VideoCapture::release to close the already opened file or camera.
675     */
676     CV_WRAP virtual bool open(int index);
677 
678    /** @brief  Open a camera for video capturing
679 
680     @overload
681 
682     Parameters are similar as the constructor VideoCapture(int index),except it takes an additional argument apiPreference.
683     Definitely, is same as open(int index) where `index=cameraNum + apiPreference`
684     @return `true` if the camera has been successfully opened.
685     */
686     CV_WRAP bool open(int cameraNum, int apiPreference);
687 
688     /** @brief Returns true if video capturing has been initialized already.
689 
690     If the previous call to VideoCapture constructor or VideoCapture::open() succeeded, the method returns
691     true.
692      */
693     CV_WRAP virtual bool isOpened() const;
694 
695     /** @brief Closes video file or capturing device.
696 
697     The method is automatically called by subsequent VideoCapture::open and by VideoCapture
698     destructor.
699 
700     The C function also deallocates memory and clears \*capture pointer.
701      */
702     CV_WRAP virtual void release();
703 
704     /** @brief Grabs the next frame from video file or capturing device.
705 
706     @return `true` (non-zero) in the case of success.
707 
708     The method/function grabs the next frame from video file or camera and returns true (non-zero) in
709     the case of success.
710 
711     The primary use of the function is in multi-camera environments, especially when the cameras do not
712     have hardware synchronization. That is, you call VideoCapture::grab() for each camera and after that
713     call the slower method VideoCapture::retrieve() to decode and get frame from each camera. This way
714     the overhead on demosaicing or motion jpeg decompression etc. is eliminated and the retrieved frames
715     from different cameras will be closer in time.
716 
717     Also, when a connected camera is multi-head (for example, a stereo camera or a Kinect device), the
718     correct way of retrieving data from it is to call VideoCapture::grab() first and then call
719     VideoCapture::retrieve() one or more times with different values of the channel parameter.
720 
721     @ref tutorial_kinect_openni
722      */
723     CV_WRAP virtual bool grab();
724 
725     /** @brief Decodes and returns the grabbed video frame.
726 
727     @param [out] image the video frame is returned here. If no frames has been grabbed the image will be empty.
728     @param flag it could be a frame index or a driver specific flag
729     @return `false` if no frames has been grabbed
730 
731     The method decodes and returns the just grabbed frame. If no frames has been grabbed
732     (camera has been disconnected, or there are no more frames in video file), the method returns false
733     and the function returns an empty image (with %cv::Mat, test it with Mat::empty()).
734 
735     @sa read()
736 
737     @note In @ref videoio_c "C API", functions cvRetrieveFrame() and cv.RetrieveFrame() return image stored inside the video
738     capturing structure. It is not allowed to modify or release the image! You can copy the frame using
739     :ocvcvCloneImage and then do whatever you want with the copy.
740      */
741     CV_WRAP virtual bool retrieve(OutputArray image, int flag = 0);
742 
743     /** @brief Stream operator to read the next video frame.
744     @sa read()
745     */
746     virtual VideoCapture& operator >> (CV_OUT Mat& image);
747 
748     /** @overload
749     @sa read()
750     */
751     virtual VideoCapture& operator >> (CV_OUT UMat& image);
752 
753     /** @brief Grabs, decodes and returns the next video frame.
754 
755     @param [out] image the video frame is returned here. If no frames has been grabbed the image will be empty.
756     @return `false` if no frames has been grabbed
757 
758     The method/function combines VideoCapture::grab() and VideoCapture::retrieve() in one call. This is the
759     most convenient method for reading video files or capturing data from decode and returns the just
760     grabbed frame. If no frames has been grabbed (camera has been disconnected, or there are no more
761     frames in video file), the method returns false and the function returns empty image (with %cv::Mat, test it with Mat::empty()).
762 
763     @note In @ref videoio_c "C API", functions cvRetrieveFrame() and cv.RetrieveFrame() return image stored inside the video
764     capturing structure. It is not allowed to modify or release the image! You can copy the frame using
765     :ocvcvCloneImage and then do whatever you want with the copy.
766      */
767     CV_WRAP virtual bool read(OutputArray image);
768 
769     /** @brief Sets a property in the VideoCapture.
770 
771     @param propId Property identifier from cv::VideoCaptureProperties (eg. cv::CAP_PROP_POS_MSEC, cv::CAP_PROP_POS_FRAMES, ...)
772     or one from @ref videoio_flags_others
773     @param value Value of the property.
774     @return `true` if the property is supported by backend used by the VideoCapture instance.
775     @note Even if it returns `true` this doesn't ensure that the property
776     value has been accepted by the capture device. See note in VideoCapture::get()
777      */
778     CV_WRAP virtual bool set(int propId, double value);
779 
780     /** @brief Returns the specified VideoCapture property
781 
782     @param propId Property identifier from cv::VideoCaptureProperties (eg. cv::CAP_PROP_POS_MSEC, cv::CAP_PROP_POS_FRAMES, ...)
783     or one from @ref videoio_flags_others
784     @return Value for the specified property. Value 0 is returned when querying a property that is
785     not supported by the backend used by the VideoCapture instance.
786 
787     @note Reading / writing properties involves many layers. Some unexpected result might happens
788     along this chain.
789     @code {.txt}
790     `VideoCapture -> API Backend -> Operating System -> Device Driver -> Device Hardware`
791     @endcode
792     The returned value might be different from what really used by the device or it could be encoded
793     using device dependent rules (eg. steps or percentage). Effective behaviour depends from device
794     driver and API Backend
795 
796     */
797     CV_WRAP virtual double get(int propId) const;
798 
799     /** @brief Open video file or a capturing device or a IP video stream for video capturing with API Preference
800 
801     @overload
802 
803     Parameters are same as the constructor VideoCapture(const String& filename, int apiPreference)
804     @return `true` if the file has been successfully opened
805 
806     The method first calls VideoCapture::release to close the already opened file or camera.
807     */
808     CV_WRAP virtual bool open(const String& filename, int apiPreference);
809 
810 protected:
811     Ptr<CvCapture> cap;
812     Ptr<IVideoCapture> icap;
813 };
814 
815 class IVideoWriter;
816 
817 /** @example videowriter_basic.cpp
818 An example using VideoCapture and VideoWriter class
819  */
820 /** @brief Video writer class.
821 
822 The class provides C++ API for writing video files or image sequences.
823  */
824 class CV_EXPORTS_W VideoWriter
825 {
826 public:
827     /** @brief Default constructors
828 
829     The constructors/functions initialize video writers.
830     -   On Linux FFMPEG is used to write videos;
831     -   On Windows FFMPEG or VFW is used;
832     -   On MacOSX QTKit is used.
833      */
834     CV_WRAP VideoWriter();
835 
836     /** @overload
837     @param filename Name of the output video file.
838     @param fourcc 4-character code of codec used to compress the frames. For example,
839     VideoWriter::fourcc('P','I','M','1') is a MPEG-1 codec, VideoWriter::fourcc('M','J','P','G') is a
840     motion-jpeg codec etc. List of codes can be obtained at [Video Codecs by
841     FOURCC](http://www.fourcc.org/codecs.php) page. FFMPEG backend with MP4 container natively uses
842     other values as fourcc code: see [ObjectType](http://www.mp4ra.org/codecs.html),
843     so you may receive a warning message from OpenCV about fourcc code conversion.
844     @param fps Framerate of the created video stream.
845     @param frameSize Size of the video frames.
846     @param isColor If it is not zero, the encoder will expect and encode color frames, otherwise it
847     will work with grayscale frames (the flag is currently supported on Windows only).
848 
849     @b Tips:
850     - With some backends `fourcc=-1` pops up the codec selection dialog from the system.
851     - To save image sequence use a proper filename (eg. `img_%02d.jpg`) and `fourcc=0`
852       OR `fps=0`. Use uncompressed image format (eg. `img_%02d.BMP`) to save raw frames.
853     - Most codecs are lossy. If you want lossless video file you need to use a lossless codecs
854       (eg. FFMPEG FFV1, Huffman HFYU, Lagarith LAGS, etc...)
855     - If FFMPEG is enabled, using `codec=0; fps=0;` you can create an uncompressed (raw) video file.
856     */
857     CV_WRAP VideoWriter(const String& filename, int fourcc, double fps,
858                 Size frameSize, bool isColor = true);
859 
860     /** @overload
861     The `apiPreference` parameter allows to specify API backends to use. Can be used to enforce a specific reader implementation
862     if multiple are available: e.g. cv::CAP_FFMPEG or cv::CAP_GSTREAMER.
863      */
864     CV_WRAP VideoWriter(const String& filename, int apiPreference, int fourcc, double fps,
865                 Size frameSize, bool isColor = true);
866 
867     /** @brief Default destructor
868 
869     The method first calls VideoWriter::release to close the already opened file.
870     */
871     virtual ~VideoWriter();
872 
873     /** @brief Initializes or reinitializes video writer.
874 
875     The method opens video writer. Parameters are the same as in the constructor
876     VideoWriter::VideoWriter.
877     @return `true` if video writer has been successfully initialized
878 
879     The method first calls VideoWriter::release to close the already opened file.
880      */
881     CV_WRAP virtual bool open(const String& filename, int fourcc, double fps,
882                       Size frameSize, bool isColor = true);
883 
884     /** @overload
885      */
886     CV_WRAP bool open(const String& filename, int apiPreference, int fourcc, double fps,
887                       Size frameSize, bool isColor = true);
888 
889     /** @brief Returns true if video writer has been successfully initialized.
890     */
891     CV_WRAP virtual bool isOpened() const;
892 
893     /** @brief Closes the video writer.
894 
895     The method is automatically called by subsequent VideoWriter::open and by the VideoWriter
896     destructor.
897      */
898     CV_WRAP virtual void release();
899 
900     /** @brief Stream operator to write the next video frame.
901     @sa write
902     */
903     virtual VideoWriter& operator << (const Mat& image);
904 
905     /** @brief Writes the next video frame
906 
907     @param image The written frame
908 
909     The function/method writes the specified image to video file. It must have the same size as has
910     been specified when opening the video writer.
911      */
912     CV_WRAP virtual void write(const Mat& image);
913 
914     /** @brief Sets a property in the VideoWriter.
915 
916      @param propId Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY)
917      or one of @ref videoio_flags_others
918 
919      @param value Value of the property.
920      @return  `true` if the property is supported by the backend used by the VideoWriter instance.
921      */
922     CV_WRAP virtual bool set(int propId, double value);
923 
924     /** @brief Returns the specified VideoWriter property
925 
926      @param propId Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY)
927      or one of @ref videoio_flags_others
928 
929      @return Value for the specified property. Value 0 is returned when querying a property that is
930      not supported by the backend used by the VideoWriter instance.
931      */
932     CV_WRAP virtual double get(int propId) const;
933 
934     /** @brief Concatenates 4 chars to a fourcc code
935 
936     @return a fourcc code
937 
938     This static method constructs the fourcc code of the codec to be used in the constructor
939     VideoWriter::VideoWriter or VideoWriter::open.
940      */
941     CV_WRAP static int fourcc(char c1, char c2, char c3, char c4);
942 
943 protected:
944     Ptr<CvVideoWriter> writer;
945     Ptr<IVideoWriter> iwriter;
946 
947     static Ptr<IVideoWriter> create(const String& filename, int fourcc, double fps,
948                                     Size frameSize, bool isColor = true);
949 };
950 
951 template<> CV_EXPORTS void DefaultDeleter<CvCapture>::operator ()(CvCapture* obj) const;
952 template<> CV_EXPORTS void DefaultDeleter<CvVideoWriter>::operator ()(CvVideoWriter* obj) const;
953 
954 //! @} videoio
955 
956 } // cv
957 
958 #endif //OPENCV_VIDEOIO_HPP
959