--- a/src/main/java/jp/ac/u_ryukyu/treevnc/TreeRFBProto.java	Thu Feb 21 16:52:21 2019 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/TreeRFBProto.java	Thu Feb 21 18:37:25 2019 +0900
@@ -80,6 +80,7 @@
     private FramebufferUpdateRectangle c1rect;
     private int c1headerPos;
     private boolean stopBroadcast;
+    public boolean multicastBlocking = true;
 
     public TreeRFBProto(boolean isTreeManager, ViewerInterface viewer) {
         nets.setMyRfb(this);
@@ -656,7 +657,7 @@
 
             if (encoding == EncodingType.ZRLE.getId()
                     || encoding == EncodingType.ZLIB.getId()) {
-                if (true)  {
+                if (multicastBlocking)  {
                     try {
                         zrleeBlocking(dataLen, reader, bytes, rect, context.getPixelFormat().bitsPerPixel/8, bufs, header);
                     } catch (DataFormatException e) {
@@ -798,6 +799,7 @@
                 c1.putLong(counter++);
             c1headerPos = c1.position();
             c1.put(header);
+            header.flip();
             c1.putInt(0);
         } else {
             deflater.deflate(c1, Deflater.SYNC_FLUSH);
@@ -1040,7 +1042,7 @@
     public synchronized void startBroadcast(ReceiverTask receiverTask) {
         BroadcastRFBListener rfbBroadcastListener = viewer.getRfbBroadcastListener();
         rfbBroadcastListener.init(this, receiverTask);
-        if (rfbBroadcastListener.isStopFlag()) {
+        if (!rfbBroadcastListener.isStopFlag()) {
             Thread rfbBroadcast = new Thread(rfbBroadcastListener, "RFBBroadcast");
             rfbBroadcast.start();
         }