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package org.opencv.highgui; /*from w ww. j a va 2 s . com*/ import java.util.List; import java.util.LinkedList; import org.opencv.core.Mat; import org.opencv.core.Size; // C++: class VideoCapture /** * <p>Class for video capturing from video files or cameras. * The class provides C++ API for capturing video from cameras or for reading * video files. Here is how the class can be used:</p> * * <p>#include "opencv2/opencv.hpp" <code></p> * * <p>// C++ code:</p> * * <p>using namespace cv;</p> * * <p>int main(int, char)</p> * * * <p>VideoCapture cap(0); // open the default camera</p> * * <p>if(!cap.isOpened()) // check if we succeeded</p> * * <p>return -1;</p> * * <p>Mat edges;</p> * * <p>namedWindow("edges",1);</p> * * <p>for(;;)</p> * * * <p>Mat frame;</p> * * <p>cap >> frame; // get a new frame from camera</p> * * <p>cvtColor(frame, edges, CV_BGR2GRAY);</p> * * <p>GaussianBlur(edges, edges, Size(7,7), 1.5, 1.5);</p> * * <p>Canny(edges, edges, 0, 30, 3);</p> * * <p>imshow("edges", edges);</p> * * <p>if(waitKey(30) >= 0) break;</p> * * * <p>// the camera will be deinitialized automatically in VideoCapture destructor</p> * * <p>return 0;</p> * * * <p>Note: In C API the black-box structure <code>CvCapture</code> is used instead * of <code>VideoCapture</code>. * </code></p> * * <p>Note:</p> * <ul> * <li> A basic sample on using the VideoCapture interface can be found at * opencv_source_code/samples/cpp/starter_video.cpp * <li> Another basic video processing sample can be found at * opencv_source_code/samples/cpp/video_dmtx.cpp * <li> (Python) A basic sample on using the VideoCapture interface can be * found at opencv_source_code/samples/python2/video.py * <li> (Python) Another basic video processing sample can be found at * opencv_source_code/samples/python2/video_dmtx.py * <li> (Python) A multi threaded video processing sample can be found at * opencv_source_code/samples/python2/video_threaded.py * </ul> * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture">org.opencv.highgui.VideoCapture</a> */ public class VideoCapture { protected final long nativeObj; protected VideoCapture(long addr) { nativeObj = addr; } // // C++: VideoCapture::VideoCapture() // /** * <p>VideoCapture constructors.</p> * * <p>Note: In C API, when you finished working with video, release * <code>CvCapture</code> structure with <code>cvReleaseCapture()</code>, or use * <code>Ptr<CvCapture></code> that calls <code>cvReleaseCapture()</code> * automatically in the destructor.</p> * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-videocapture">org.opencv.highgui.VideoCapture.VideoCapture</a> */ public VideoCapture() { nativeObj = n_VideoCapture(); return; } // // C++: VideoCapture::VideoCapture(int device) // /** * <p>VideoCapture constructors.</p> * * <p>Note: In C API, when you finished working with video, release * <code>CvCapture</code> structure with <code>cvReleaseCapture()</code>, or use * <code>Ptr<CvCapture></code> that calls <code>cvReleaseCapture()</code> * automatically in the destructor.</p> * * @param device id of the opened video capturing device (i.e. a camera index). * If there is a single camera connected, just pass 0. * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-videocapture">org.opencv.highgui.VideoCapture.VideoCapture</a> */ public VideoCapture(int device) { nativeObj = n_VideoCapture(device); return; } // // C++: double VideoCapture::get(int propId) // /** * Returns the specified "VideoCapture" property. * * Note: When querying a property that is not supported by the backend used by * the "VideoCapture" class, value 0 is returned. * * @param propId property identifier; it can be one of the following: * * CV_CAP_PROP_FRAME_WIDTH width of the frames in the video stream. * * CV_CAP_PROP_FRAME_HEIGHT height of the frames in the video stream. * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-get">org.opencv.highgui.VideoCapture.get</a> */ public double get(int propId) { double retVal = n_get(nativeObj, propId); return retVal; } public List<Size> getSupportedPreviewSizes() { String[] sizes_str = n_getSupportedPreviewSizes(nativeObj).split(","); List<Size> sizes = new LinkedList<Size>(); for (String str : sizes_str) { String[] wh = str.split("x"); sizes.add(new Size(Double.parseDouble(wh[0]), Double.parseDouble(wh[1]))); } return sizes; } // // C++: bool VideoCapture::grab() // /** * <p>Grabs the next frame from video file or capturing device.</p> * * <p>The methods/functions grab the next frame from video file or camera and * return true (non-zero) in the case of success.</p> * * <p>The primary use of the function is in multi-camera environments, especially * when the cameras do not have hardware synchronization. That is, you call * <code>VideoCapture.grab()</code> for each camera and after that call the * slower method <code>VideoCapture.retrieve()</code> to decode and get frame * from each camera. This way the overhead on demosaicing or motion jpeg * decompression etc. is eliminated and the retrieved frames from different * cameras will be closer in time.</p> * * <p>Also, when a connected camera is multi-head (for example, a stereo camera or * a Kinect device), the correct way of retrieving data from it is to call * "VideoCapture.grab" first and then call "VideoCapture.retrieve" one or more * times with different values of the <code>channel</code> parameter. See * https://github.com/Itseez/opencv/tree/master/samples/cpp/openni_capture.cpp</p> * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-grab">org.opencv.highgui.VideoCapture.grab</a> */ public boolean grab() { boolean retVal = n_grab(nativeObj); return retVal; } // // C++: bool VideoCapture::isOpened() // /** * <p>Returns true if video capturing has been initialized already.</p> * * <p>If the previous call to <code>VideoCapture</code> constructor or * <code>VideoCapture.open</code> succeeded, the method returns true.</p> * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-isopened">org.opencv.highgui.VideoCapture.isOpened</a> */ public boolean isOpened() { boolean retVal = n_isOpened(nativeObj); return retVal; } // // C++: bool VideoCapture::open(int device) // /** * <p>Open video file or a capturing device for video capturing</p> * * <p>The methods first call "VideoCapture.release" to close the already opened * file or camera.</p> * * @param device id of the opened video capturing device (i.e. a camera index). * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-open">org.opencv.highgui.VideoCapture.open</a> */ public boolean open(int device) { boolean retVal = n_open(nativeObj, device); return retVal; } // // C++: bool VideoCapture::read(Mat image) // /** * <p>Grabs, decodes and returns the next video frame.</p> * * <p>The methods/functions combine "VideoCapture.grab" and "VideoCapture.retrieve" * in one call. This is the most convenient method for reading video files or * capturing data from decode and return the just grabbed frame. If no frames * has been grabbed (camera has been disconnected, or there are no more frames * in video file), the methods return false and the functions return NULL * pointer.</p> * * <p>Note: OpenCV 1.x functions <code>cvRetrieveFrame</code> and <code>cv.RetrieveFrame</code> * return image stored inside the video capturing structure. It is not allowed * to modify or release the image! You can copy the frame using "cvCloneImage" * and then do whatever you want with the copy.</p> * * @param image a image * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-read">org.opencv.highgui.VideoCapture.read</a> */ public boolean read(Mat image) { boolean retVal = n_read(nativeObj, image.nativeObj); return retVal; } // // C++: void VideoCapture::release() // /** * <p>Closes video file or capturing device.</p> * * <p>The methods are automatically called by subsequent "VideoCapture.open" and * by <code>VideoCapture</code> destructor.</p> * * <p>The C function also deallocates memory and clears <code>*capture</code> * pointer.</p> * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-release">org.opencv.highgui.VideoCapture.release</a> */ public void release() { n_release(nativeObj); return; } // // C++: bool VideoCapture::retrieve(Mat image, int channel = 0) // /** * <p>Decodes and returns the grabbed video frame.</p> * * <p>The methods/functions decode and return the just grabbed frame. If no frames * has been grabbed (camera has been disconnected, or there are no more frames * in video file), the methods return false and the functions return NULL * pointer.</p> * * <p>Note: OpenCV 1.x functions <code>cvRetrieveFrame</code> and <code>cv.RetrieveFrame</code> * return image stored inside the video capturing structure. It is not allowed * to modify or release the image! You can copy the frame using "cvCloneImage" * and then do whatever you want with the copy.</p> * * @param image a image * @param channel a channel * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-retrieve">org.opencv.highgui.VideoCapture.retrieve</a> */ public boolean retrieve(Mat image, int channel) { boolean retVal = n_retrieve(nativeObj, image.nativeObj, channel); return retVal; } /** * <p>Decodes and returns the grabbed video frame.</p> * * <p>The methods/functions decode and return the just grabbed frame. If no frames * has been grabbed (camera has been disconnected, or there are no more frames * in video file), the methods return false and the functions return NULL * pointer.</p> * * <p>Note: OpenCV 1.x functions <code>cvRetrieveFrame</code> and <code>cv.RetrieveFrame</code> * return image stored inside the video capturing structure. It is not allowed * to modify or release the image! You can copy the frame using "cvCloneImage" * and then do whatever you want with the copy.</p> * * @param image a image * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-retrieve">org.opencv.highgui.VideoCapture.retrieve</a> */ public boolean retrieve(Mat image) { boolean retVal = n_retrieve(nativeObj, image.nativeObj); return retVal; } // // C++: bool VideoCapture::set(int propId, double value) // /** * Sets a property in the "VideoCapture". * * @param propId property identifier; it can be one of the following: * * CV_CAP_PROP_FRAME_WIDTH width of the frames in the video stream. * * CV_CAP_PROP_FRAME_HEIGHT height of the frames in the video stream. * @param value value of the property. * * @see <a href="http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html#videocapture-set">org.opencv.highgui.VideoCapture.set</a> */ public boolean set(int propId, double value) { boolean retVal = n_set(nativeObj, propId, value); return retVal; } @Override protected void finalize() throws Throwable { n_delete(nativeObj); super.finalize(); } // C++: VideoCapture::VideoCapture() private static native long n_VideoCapture(); // C++: VideoCapture::VideoCapture(string filename) private static native long n_VideoCapture(java.lang.String filename); // C++: VideoCapture::VideoCapture(int device) private static native long n_VideoCapture(int device); // C++: double VideoCapture::get(int propId) private static native double n_get(long nativeObj, int propId); // C++: bool VideoCapture::grab() private static native boolean n_grab(long nativeObj); // C++: bool VideoCapture::isOpened() private static native boolean n_isOpened(long nativeObj); // C++: bool VideoCapture::open(string filename) private static native boolean n_open(long nativeObj, java.lang.String filename); // C++: bool VideoCapture::open(int device) private static native boolean n_open(long nativeObj, int device); // C++: bool VideoCapture::read(Mat image) private static native boolean n_read(long nativeObj, long image_nativeObj); // C++: void VideoCapture::release() private static native void n_release(long nativeObj); // C++: bool VideoCapture::retrieve(Mat image, int channel = 0) private static native boolean n_retrieve(long nativeObj, long image_nativeObj, int channel); private static native boolean n_retrieve(long nativeObj, long image_nativeObj); // C++: bool VideoCapture::set(int propId, double value) private static native boolean n_set(long nativeObj, int propId, double value); private static native String n_getSupportedPreviewSizes(long nativeObj); // native support for java finalize() private static native void n_delete(long nativeObj); }