From 9ca0368803531e47df01fdfd3db30786cbb52ab1 Mon Sep 17 00:00:00 2001
From: Lyubomir Marinov <lyubomir.marinov@jitsi.org>
Date: Wed, 9 Nov 2011 20:27:07 +0000
Subject: [PATCH] Reduces the number of times that Jitsi's CaptureDevices get
 started/stopped in order to, for example, bring down the number of times that
 (some) webcams flash on and off.

---
 .../protocol/AbstractBufferCaptureDevice.java | 100 +++++++++++++++---
 1 file changed, 85 insertions(+), 15 deletions(-)

diff --git a/src/net/java/sip/communicator/impl/neomedia/jmfext/media/protocol/AbstractBufferCaptureDevice.java b/src/net/java/sip/communicator/impl/neomedia/jmfext/media/protocol/AbstractBufferCaptureDevice.java
index 822118638..077c6a3aa 100644
--- a/src/net/java/sip/communicator/impl/neomedia/jmfext/media/protocol/AbstractBufferCaptureDevice.java
+++ b/src/net/java/sip/communicator/impl/neomedia/jmfext/media/protocol/AbstractBufferCaptureDevice.java
@@ -11,13 +11,15 @@
 import java.util.*;
 
 import javax.media.*;
-import javax.media.Controls; // disambiguation
+import javax.media.Controls;
 import javax.media.control.*;
 import javax.media.protocol.*;
 
 import net.java.sip.communicator.impl.neomedia.control.*;
 import net.java.sip.communicator.util.*;
 
+import com.sun.media.util.*;
+
 /**
  * Facilitates the implementations of the <tt>CaptureDevice</tt> and
  * <tt>DataSource</tt> interfaces provided by
@@ -71,6 +73,11 @@ public abstract class AbstractBufferCaptureDevice
      */
     private FrameRateControl[] frameRateControls;
 
+    /**
+     * The <tt>RTPInfo</tt>s of this <tt>AbstractBufferCaptureDevice</tt>.
+     */
+    private RTPInfo[] rtpInfos;
+
     /**
      * The indicator which determines whether the transfer of media data from
      * this <tt>DataSource</tt> has been started.
@@ -225,6 +232,26 @@ protected FrameRateControl createFrameRateControl()
         return null;
     }
 
+    /**
+     * Creates a new <tt>RTPInfo</tt> instance of this
+     * <tt>AbstractBufferCaptureDevice</tt>.
+     *
+     * @return a new <tt>RTPInfo</tt> instance  of this
+     * <tt>AbstractBufferCaptureDevice</tt>
+     */
+    protected RTPInfo createRTPInfo()
+    {
+        return
+            new RTPInfo()
+                    {
+                        public String getCNAME()
+                        {
+                            // TODO Auto-generated method stub
+                            return null;
+                        }
+                    };
+    }
+
     /**
      * Create a new <tt>AbstractBufferStream</tt> which is to be at a specific
      * zero-based index in the list of streams of this
@@ -289,27 +316,48 @@ final void defaultDoStop()
     final Object[] defaultGetControls()
     {
         FormatControl[] formatControls = internalGetFormatControls();
+        int formatControlCount
+            = (formatControls == null) ? 0 : formatControls.length;
         FrameRateControl[] frameRateControls = internalGetFrameRateControls();
-
-        if (((formatControls == null) || (formatControls.length == 0))
-                && ((frameRateControls == null)
-                        || (frameRateControls.length == 0)))
+        int frameRateControlCount
+            = (frameRateControls == null) ? 0 : frameRateControls.length;
+        RTPInfo[] rtpInfos = internalGetRTPInfos();
+        int rtpInfoCount = (rtpInfos == null) ? 0 : rtpInfos.length;
+
+        if ((formatControlCount == 0)
+                && (frameRateControlCount == 0)
+                && (rtpInfoCount == 0))
             return ControlsAdapter.EMPTY_CONTROLS;
         else
         {
             Object[] controls
-                = new Object[formatControls.length + frameRateControls.length];
+                = new Object[
+                             formatControlCount
+                                 + frameRateControlCount
+                                 + rtpInfoCount];
             int offset = 0;
 
-            System.arraycopy(
-                    formatControls, 0,
-                    controls, offset,
-                    formatControls.length);
-            offset += formatControls.length;
-            System.arraycopy(
-                    frameRateControls, 0,
-                    controls, offset,
-                    frameRateControls.length);
+            if (formatControlCount != 0)
+            {
+                System.arraycopy(
+                        formatControls, 0,
+                        controls, offset,
+                        formatControlCount);
+                offset += formatControlCount;
+            }
+            if (frameRateControlCount != 0)
+            {
+                System.arraycopy(
+                        frameRateControls, 0,
+                        controls, offset,
+                        frameRateControlCount);
+                offset += frameRateControlCount;
+            }
+            if (rtpInfoCount != 0)
+            {
+                System.arraycopy(rtpInfos, 0, controls, offset, rtpInfoCount);
+                offset += rtpInfoCount;
+            }
             return controls;
         }
     }
@@ -688,6 +736,28 @@ private synchronized FrameRateControl[] internalGetFrameRateControls()
         return frameRateControls;
     }
 
+    /**
+     * Gets an array of <tt>RTPInfo</tt> instances of this
+     * <tt>AbstractBufferCaptureDevice</tt>.
+     *
+     * @return an array of <tt>RTPInfo</tt> instances of this
+     * <tt>AbstractBufferCaptureDevice</tt>.
+     */
+    private synchronized RTPInfo[] internalGetRTPInfos()
+    {
+        if (rtpInfos == null)
+        {
+            RTPInfo rtpInfo = createRTPInfo();
+
+            // Don't try to create the RTPInfo more than once.
+            rtpInfos
+                = (rtpInfo == null)
+                    ? new RTPInfo[0]
+                    : new RTPInfo[] { rtpInfo };
+        }
+        return rtpInfos;
+    }
+
     /**
      * Attempts to set the <tt>Format</tt> to be reported by the
      * <tt>FormatControl</tt> of a <tt>PushBufferStream</tt> at a specific