That is, you call VideoCapture::grab() for each camera and after that call the slower method VideoCapture::retrieve() to decode and get frame from each camera. The primary use of the function is in multi-camera environments, especially when the cameras do not have hardware synchronization.
The method/function grabs the next frame from video file or camera and returns true (non-zero) in the case of success. Returns true (non-zero) in the case of success. Grabs the next frame from video file or capturing device. Constructor & Destructor Documentation ◆ VideoCapture()
More.Ĭloses video file or capturing device. Grabs, decodes and returns the next video frame. Stream operator to read the next video frame. Open (int index, int apiPreference, const std::vector ¶ms) Open (int index, int apiPreference= CAP_ANY) Open (const String &filename, int apiPreference, const std::vector ¶ms) Opens a video file or a capturing device or an IP video stream for video capturing. Open (const String &filename, int apiPreference= CAP_ANY) Returns true if video capturing has been initialized already. Returns the specified VideoCapture property. Opens a camera for video capturing with API Preference and parameters. VideoCapture (int index, int apiPreference, const std::vector ¶ms) VideoCapture (int index, int apiPreference= CAP_ANY) Opens a video file or a capturing device or an IP video stream for video capturing with API Preference and parameters. VideoCapture (const String &filename, int apiPreference, const std::vector ¶ms) Opens a video file or a capturing device or an IP video stream for video capturing with API Preference. VideoCapture (const String &filename, int apiPreference= CAP_ANY) Class for video capturing from video files, image sequences or cameras.