From 24dcfa1a4f9fab01826653577b8891c0bd11a300 Mon Sep 17 00:00:00 2001
From: Vadim Pisarevsky <no@email>
Date: Sun, 29 May 2011 21:02:53 +0000
Subject: [PATCH] removed confusing CvCapture::queryFrame(); rewritten
 cvQueryFrame() (ticket #235)

---
 modules/highgui/src/cap.cpp      |  6 +++++-
 modules/highgui/src/cap_qtkit.mm | 19 -------------------
 modules/highgui/src/precomp.hpp  |  1 -
 3 files changed, 5 insertions(+), 21 deletions(-)

diff --git a/modules/highgui/src/cap.cpp b/modules/highgui/src/cap.cpp
index a5b94cb..0914822 100644
--- a/modules/highgui/src/cap.cpp
+++ b/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);
 }
 
 
diff --git a/modules/highgui/src/cap_qtkit.mm b/modules/highgui/src/cap_qtkit.mm
index 80b043c..c999ce7 100644
--- a/modules/highgui/src/cap_qtkit.mm
+++ b/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];
diff --git a/modules/highgui/src/precomp.hpp b/modules/highgui/src/precomp.hpp
index 1a96b41..8e3b173 100644
--- a/modules/highgui/src/precomp.hpp
+++ b/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...
 };
 
-- 
2.7.4