video-capture

I want to connect to a camera, and only capture a frame when an event happens (e.g. keypress). A simplified version of what I'd like to do is this: cap = cv2.VideoCapture(device_id) while True: if event: img = cap.read() preprocess(img) process(img) cv.Waitkey(10) However, cap.read seems to only capture the next frame in the queue, and not the latest. I did a lot of searching online, and there seems to be a lot of questions on this but no definitive answer. Only some dirty hacks which involve opening and closing the capture device just before and after grabbing (which won't work for me as my

I am making a video recorder and i want to have the time duration of how much time did the user have recorder the video. The time will counts upwards. in order to calculate the time, im using thread and the calculation start when the user click the start button and it will stop when the user click the stop button. for the timer thread im referring the tutorial from here . however my problem here is the timer is not working and i think the thread is not doing its job. below is my logcat. Here's my code for the main activity public class Videotest1Activity extends Activity implements

Have an AVI videofile, and a webcam. cvQueryFrame returns null in both cases. Code is applied(only for cam): #include "highgui.h" #include <iostream> using namespace std; int main( int argc, char** argv ) { cvNamedWindow( "KillCam", CV_WINDOW_AUTOSIZE ); cvWaitKey(0); CvCapture* capture = cvCreateCameraCapture(-1); assert(capture != NULL); IplImage* frame; while(1){ frame = cvQueryFrame( capture ); if( !frame ) break; cvShowImage( "KillCam", frame ); char c = cvWaitKey(33); if( c == 30 ) break; } cvReleaseCapture( &capture ); cvDestroyWindow( "KillCam" ); } I found, by stepping into the openCV

I am trying to record video to an external SD card. However, everytime I try and acutally record the data -- I always get a java.io.FileNotFound exception. I was wondering if anyone knew of any tutorials or could help correct my code. Here is the class in which tries to record video public class VideoActivity extends Activity { private SurfaceView preview; private SurfaceHolder previewHolder; private String locationName; private String filepath; private File video; public void onCreate(Bundle videocawk) { super.onCreate(videocawk); setContentView(R.layout.video_layout); setSurface();