fixed problem with non 4:3 cameras (ticket #142)

modules/highgui/src/cap_dshow.cpp

@@ -2893,7 +2893,7 @@ public:
 protected:
     void init();
 
-    int index;
+    int index, width, height;
     IplImage* frame;
     static videoInput VI;
 };
@@ -2911,6 +2911,7 @@ CvCaptureCAM_DShow::CvCaptureCAM_DShow()
 {
     index = -1;
     frame = 0;
+    width = height = -1;
 }
 
 void CvCaptureCAM_DShow::close()
@@ -2921,6 +2922,7 @@ void CvCaptureCAM_DShow::close()
         index = -1;
         cvReleaseImage(&frame);
     }
+    width = height = -1;
 }
 
 // Initialize camera input
@@ -2977,28 +2979,29 @@ double CvCaptureCAM_DShow::getProperty( int property_id )
 
 bool CvCaptureCAM_DShow::setProperty( int property_id, double value )
 {
-    int width = 0, height = 0;
-
     switch( property_id )
     {
     case CV_CAP_PROP_FRAME_WIDTH:
         width = cvRound(value);
-        height = width*3/4;
         break;
     case CV_CAP_PROP_FRAME_HEIGHT:
         height = cvRound(value);
-        width = height*4/3;
     default:
         return false;
     }
 
+    if( width > 0 && height > 0 )
+    {
         if( width != VI.getWidth(index) || height != VI.getHeight(index) )
         {
             VI.stopDevice(index);
             VI.setupDevice(index, width, height);
         }
+        width = height = -1;
         return VI.isDeviceSetup(index);
     }
+    return true;
+}
 
 
 CvCapture* cvCreateCameraCapture_DShow( int index )