1 int main( int argc, char** argv ) { 2     cvNamedWindow( "Example2_9", CV_WINDOW_AUTOSIZE ); 3     CvCapture* capture; 4     if (argc==1) { 5         capture = cvCreateCameraCapture( 0 ); 6     } else { 7         capture = cvCreateFileCapture( argv[1] ); 8     } 9     assert( capture != NULL );10 11     IplImage* frame;12     while(1) {13         frame = cvQueryFrame( capture );14         if( !frame ) break;15         cvShowImage( "Example2_9", frame );16         char c = cvWaitKey(10);17         if( c == 27 ) break;18     }19     cvReleaseCapture( &capture );20     cvDestroyWindow( "Example2_9" );21 }