Improved robustness of videobuffer

src/videobuffer.cpp

@@ -21,6 +21,7 @@
 
 
 void imageCollectionThread(void* arg);
+void getALPRImages(cv::VideoCapture cap, VideoDispatcher* dispatcher);
 
 
 VideoBuffer::VideoBuffer()
@@ -102,6 +103,27 @@ void imageCollectionThread(void* arg)
       cv::VideoCapture cap=cv::VideoCapture();
       cap.open(dispatcher->mjpeg_url);
       
+      getALPRImages(cap, dispatcher);
+
+    }
+    catch (const std::runtime_error& error)
+    {
+      // Error occured while trying to gather image.  Retry, don't exit.
+      std::cerr << "VideoBuffer exception: " << error.what() << std::endl;
+    }
+    // Delay 1 second
+    usleep(1000000);
+    
+  }
+
+  
+}
+
+
+// Continuously grabs images from the video capture.  If there is an error,
+// it returns so that the video capture can be recreated.
+void getALPRImages(cv::VideoCapture cap, VideoDispatcher* dispatcher)
+{
   cv::Mat frame;
   
   while (dispatcher->active)
@@ -114,16 +136,23 @@ void imageCollectionThread(void* arg)
       try
       {
 	hasImage = cap.read(frame);
-	    dispatcher->setLatestFrame(&frame);
-	  }
-	  catch (int e)
-	  {
-	    // Error occured while trying to gather image.  Retry, don't exit.
-	    std::cerr << "Exception happened " << e << std::endl;
-	  }
 	// Double check the image to make sure it's valid.
 	if (frame.cols == 0 || frame.rows == 0)
-	    hasImage = false;
+	{
+	  dispatcher->mMutex.unlock();
+	  return;
+	}
+	
+	dispatcher->setLatestFrame(&frame);
+      }
+      catch (const std::runtime_error& error)
+      {
+	// Error occured while trying to gather image.  Retry, don't exit.
+	std::cerr << "Exception happened " <<  error.what() << std::endl;
+	dispatcher->mMutex.unlock();
+	return;
+      }
+
       
       dispatcher->mMutex.unlock();
       
@@ -139,15 +168,3 @@ void imageCollectionThread(void* arg)
     usleep(100000);
   }
 }
-    catch (const std::runtime_error& error)
-    {
-      // Error occured while trying to gather image.  Retry, don't exit.
-      std::cerr << "VideoBuffer exception: " << error.what() << std::endl;
-    }
-    // Delay 1 second
-    usleep(1000000);
-    
-  }
-
-  
-}