removed confusing CvCapture::queryFrame(); rewritten cvQueryFrame() (ticket #235)

modules/highgui/src/cap.cpp

@@ -73,7 +73,11 @@ CV_IMPL void cvReleaseCapture( CvCapture** pcapture )
 
 CV_IMPL IplImage* cvQueryFrame( CvCapture* capture )
 {
-    return capture ? capture->queryFrame() : 0;
+    if(!capture)
+        return 0;
+    if(!capture->grabFrame())
+        return 0;
+    return capture->retrieveFrame(0);
 }
 
 

modules/highgui/src/cap_qtkit.mm

@@ -99,7 +99,6 @@ public:
 	~CvCaptureCAM(); 
 	virtual bool grabFrame(); 
 	virtual IplImage* retrieveFrame(int);
-	virtual IplImage* queryFrame(); 
 	virtual double getProperty(int property_id); 
 	virtual bool setProperty(int property_id, double value); 
 	virtual int didStart(); 
@@ -142,7 +141,6 @@ public:
 	~CvCaptureFile(); 
 	virtual bool grabFrame(); 
 	virtual IplImage* retrieveFrame(int);
-	virtual IplImage* queryFrame(); 
 	virtual double getProperty(int property_id); 
 	virtual bool setProperty(int property_id, double value); 
 	virtual int didStart(); 
@@ -294,18 +292,6 @@ IplImage* CvCaptureCAM::retrieveFrame(int) {
 	return [capture getOutput]; 
 }
 
-IplImage* CvCaptureCAM::queryFrame() {
-	while (!grabFrame()) {
-		cout << "WARNING: Couldn't grab new frame from camera!!!" << endl; 
-		/*
-		cout << "Attempting to restart camera; set capture property DISABLE_AUTO_RESTART to disable." << endl; 		
-		stopCaptureDevice(); 
-		startCaptureDevice(camNum); 
-		 */
-	}
-	return retrieveFrame(0); 
-}	
-
 void CvCaptureCAM::stopCaptureDevice() {
 	NSAutoreleasePool* localpool = [[NSAutoreleasePool alloc] init];
 	
@@ -781,11 +767,6 @@ IplImage* CvCaptureFile::retrieveFrame(int) {
 	return retrieveFramePixelBuffer(); 
 }
 
-IplImage* CvCaptureFile::queryFrame() {
-	grabFrame(); 
-	return retrieveFrame(0); 
-}	
-
 double CvCaptureFile::getFPS() {
 	if (mCaptureSession == nil) return 0; 
 	NSAutoreleasePool* localpool = [[NSAutoreleasePool alloc] init];

modules/highgui/src/precomp.hpp

@@ -98,7 +98,6 @@ struct CvCapture
     virtual bool setProperty(int, double) { return 0; }
     virtual bool grabFrame() { return true; }
     virtual IplImage* retrieveFrame(int) { return 0; }
-    virtual IplImage* queryFrame() { return grabFrame() ? retrieveFrame(0) : 0; }
 	virtual int getCaptureDomain() { return CV_CAP_ANY; } // Return the type of the capture object: CV_CAP_VFW, etc...
 };