From ddcb961feeffcf2c839947e9cebbb9bd52e6f594 Mon Sep 17 00:00:00 2001
From: Emil Ivov <emcho@jitsi.org>
Date: Tue, 8 Jan 2013 18:52:09 +0000
Subject: [PATCH] Tries to work around Offer/Answer negotiation issues in cases
 where an offending remote system would try to remap a payload type that has
 been previously allocated to a different format.

---
 .../jabber/jinglesdp/JingleUtils.java         |  8 +++++--
 .../impl/protocol/sip/sdp/SdpUtils.java       | 10 ++++++--
 .../media/DynamicPayloadTypeRegistry.java     | 24 +++++++++++++++----
 3 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/src/net/java/sip/communicator/impl/protocol/jabber/jinglesdp/JingleUtils.java b/src/net/java/sip/communicator/impl/protocol/jabber/jinglesdp/JingleUtils.java
index 02b9c67fb..cae2c2899 100644
--- a/src/net/java/sip/communicator/impl/protocol/jabber/jinglesdp/JingleUtils.java
+++ b/src/net/java/sip/communicator/impl/protocol/jabber/jinglesdp/JingleUtils.java
@@ -200,8 +200,12 @@ public static MediaFormat payloadTypeToMediaFormat(
          */
         if ((ptRegistry != null)
                 && (pt >= MediaFormat.MIN_DYNAMIC_PAYLOAD_TYPE)
-                && (pt <= MediaFormat.MAX_DYNAMIC_PAYLOAD_TYPE)
-                && (ptRegistry.findFormat(pt) == null))
+                && (pt <= MediaFormat.MAX_DYNAMIC_PAYLOAD_TYPE))
+                //some systems will violate 3264 by reusing previously defined
+                //payload types for new formats. we try and salvage that
+                //situation by creating an overriding mapping in such cases
+                //we therefore don't do the following check.
+                //&& (ptRegistry.findFormat(pt) == null))
         {
             ptRegistry.addMapping(format, pt);
         }
diff --git a/src/net/java/sip/communicator/impl/protocol/sip/sdp/SdpUtils.java b/src/net/java/sip/communicator/impl/protocol/sip/sdp/SdpUtils.java
index 5e1b48d5a..1a38e5afc 100644
--- a/src/net/java/sip/communicator/impl/protocol/sip/sdp/SdpUtils.java
+++ b/src/net/java/sip/communicator/impl/protocol/sip/sdp/SdpUtils.java
@@ -771,9 +771,15 @@ private static MediaFormat createFormat(
         if ((payloadType >= MediaFormat.MIN_DYNAMIC_PAYLOAD_TYPE)
                 && (payloadType
                         <= MediaFormat.MAX_DYNAMIC_PAYLOAD_TYPE)
-                && (format != null)
-                && (ptRegistry.findFormat(payloadType) == null))
+                && (format != null))
+                //some systems will violate 3264 by reusing previously defined
+                //payload types for new formats. we try and salvage that
+                //situation by creating an overriding mapping in such cases
+                //we therefore don't do the following check.
+                //&& (ptRegistry.findFormat(payloadType) == null))
+        {
             ptRegistry.addMapping(format, payloadType);
+        }
 
         return format;
     }
diff --git a/src/net/java/sip/communicator/service/protocol/media/DynamicPayloadTypeRegistry.java b/src/net/java/sip/communicator/service/protocol/media/DynamicPayloadTypeRegistry.java
index 1893a923e..8d2171436 100644
--- a/src/net/java/sip/communicator/service/protocol/media/DynamicPayloadTypeRegistry.java
+++ b/src/net/java/sip/communicator/service/protocol/media/DynamicPayloadTypeRegistry.java
@@ -8,6 +8,8 @@
 
 import java.util.*;
 
+import net.java.sip.communicator.impl.protocol.sip.*;
+import net.java.sip.communicator.util.*;
 import org.jitsi.service.neomedia.*;
 import org.jitsi.service.neomedia.format.*;
 
@@ -30,6 +32,11 @@
  */
 public class DynamicPayloadTypeRegistry
 {
+    /**
+     * Our class logger.
+     */
+    private static final Logger logger
+        = Logger.getLogger(DynamicPayloadTypeRegistry.class);
     /**
      * A field that we use to track dynamic payload numbers that we allocate.
      */
@@ -244,12 +251,13 @@ public void addMapping(MediaFormat format, byte payloadType)
         throws IllegalArgumentException
     {
         MediaFormat alreadyMappedFmt = findFormat(payloadType);
-
         if(alreadyMappedFmt != null)
         {
-            throw new IllegalArgumentException(
-                    payloadType + " has already been allocated to "
-                        + alreadyMappedFmt);
+            logger.warn("Remote party is trying to remap payload type "
+                        + payloadType + " and reassign it from "
+                        + alreadyMappedFmt + " to " + format
+                        + ". We'll go along but there might be issues because"
+                        + " of this.");
         }
 
         if( payloadType < MediaFormat.MIN_DYNAMIC_PAYLOAD_TYPE)
@@ -267,7 +275,13 @@ public void addMapping(MediaFormat format, byte payloadType)
         if(payloadTypeMappings.containsKey(format))
         {
             byte originalPayloadType = payloadTypeMappings.get(format);
-            payloadTypeOverrides.put(originalPayloadType, payloadType);
+
+            if(originalPayloadType != payloadType)
+            {
+                payloadTypeOverrides.put(originalPayloadType, payloadType);
+            }
+            //else: we already have the exact same mapping, so no need to
+            //override anything.
         }
         else
         {