Add pin parsing from URL for sender (patch from pgerwinski)

sender/camera-sender.html

@@ -12,23 +12,31 @@
         <div>
             Leave the pin empty if the rooms has none set.
         </div>
+        <p>
             <select id="res-select">
                 <option value="lowres">320x240</option>
                 <option value="lowres-16:9">320x180</option>
-            <option value="stdres">640x480</option>
+                <option value="stdres" selected>640x480</option>
                 <option value="stdres-16:9">640x360</option>
                 <option value="hires-4:3">960x720</option>
                 <option value="hires-16:9">1280x720</option>
             </select>
+<!--
             <input type="password" id="pin-input" placeholder="Room pin" />
+-->
             <button id="start" disabled>Start</button>
             <button id="stop" disabled>Stop</button>
+        </p>
+
+        <p>
             <form id="bandwidth-form">
-            <label>A bandwidth cap can be set here. 0 or negative means no cap.</label>
+                <label>While the camera is running, a bandwidth cap can be set here. 0 or negative means no cap.</label>
                 <br />
                 <input type="text" id="bandwidth-input" placeholder="New bitrate [in kbit/s]" />
                 <input type="submit" id="bandwidth-submit" value="Change" disabled />
             </form>
+        </p>
+
         <div id="preview-container"></div>
     </body>
 </html>

sender/camera-sender.js

@@ -14,13 +14,15 @@ document.addEventListener('DOMContentLoaded', function() {
     var room = 1006;
     var slot = 0;
     var token = '';
+    var pin = '';
     var feedId = null;
 
     parseRoomFromURL();
     parseSlotFromURL();
+    parsePinFromURL();
     parseTokenFromURL();
 
-    roomIndicator.innerText = `VNC ${room - 1000} (Room ${room}) - Slot ${slot} - Token: ${token || '*none*'}`;
+    roomIndicator.innerText = `Channel ${room - 1000}, Camera ${slot + 1}`;
 
     const socketNumber = room + 4000;
     const socket = io('https://' + window.location.hostname, {
@@ -100,13 +102,11 @@ document.addEventListener('DOMContentLoaded', function() {
 
                             startButton.onclick = function() {
                                 var resSelect = document.getElementById('res-select');
-                                var pinInput = document.getElementById('pin-input');
                                 startButton.setAttribute('disabled', '');
                                 resSelect.setAttribute('disabled', '');
                                 sendResolution = resSelect.value;
                                 Janus.log('sendResolution:', sendResolution);
-                                shareCamera(pinInput.value);
-                                pinInput.value = '';
+                                shareCamera(pin);
                             };
                             startButton.removeAttribute('disabled');
                         },
@@ -247,6 +247,16 @@ document.addEventListener('DOMContentLoaded', function() {
         }
     }
 
+    function parsePinFromURL() {
+        var urlParams = new URLSearchParams(window.location.search);
+        var pinParam = urlParams.get('pin');
+        if (pinParam != null) {
+            pin = pinParam;
+        } else {
+            console.log('Got no valid pin in URL search params');
+        }
+    }
+
     function parseTokenFromURL() {
         var urlParams = new URLSearchParams(window.location.search);
         var tokenParam = urlParams.get('token');