Modificato il main.js

reso funzionante lo script, reinstaziando l' oggetto e facendo lo stop
di tutte le tracks 
consiglio di cambiare libreria poichè presenta numerosi bug

things/static/things/main.js

@@ -8,7 +8,8 @@ $(function () {
             return;
         }
         $("input#id_id")[0].value = result;
-        $("#qr-scan").modal("hide");
+        $("#qr-scan").modal("toggle");
+        
     };
 
     $("#cameraProcess").click(function(e) {
@@ -30,16 +31,30 @@ $(function () {
         }
         var video = document.querySelector("video");
         var reset = document.querySelector("#reset");
-
+        var stop = document.querySelector('#stop');
+        
         // prepare a canvas element that will receive the image to decode, sets
         // the callback for the result and then prepares the videoElement to
         // send its source to the decoder.
-        qr.decodeFromCamera(video, resultHandler);
+        qr.decodeFromCamera(video, resultHandler,true);
         // attach some event handlers to reset and stop whenever we want.
         reset.onclick = function () {
-            qr.decodeFromCamera(video, resultHandler);
+        	for (var i = 0; i < qr.stream.getTracks().length; i++){
+        		qr.stream.getTracks()[i].stop();
+            	
+            }
+        	qr = new QCodeDecoder();	            
+            qr.decodeFromCamera(video, resultHandler,true);
+          
+            
         };
+      
     }).on("hide.bs.modal", function() {
-        qr.stop();
+    	for (var i = 0; i < qr.stream.getTracks().length; i++){
+    		qr.stream.getTracks()[i].stop();
+        	
+        }
+     qr = new QCodeDecoder();	
+    
     });
 });