Fix #1438: Video Stream are cut when, in a same PeeConnection, Video stream are added/removed

Also add missing code in SendRtpRaw() and in SendRtcpTWCCFeedback() when text as MediaType is used
Remove redundancy code
Use same tests for video than ones used for audio or text

Author: ChristopheI

src/net/RTP/RTPSession.cs

@@ -1239,9 +1239,12 @@ public virtual SetDescriptionResultEnum SetRemoteDescription(SdpType sdpType, SD
                             return SetDescriptionResultEnum.TextIncompatible;
                         }
                     }
-                    else if (currentMediaStream.RemoteTrack.Capabilities.Count != 0 && announcement.Port != 0 && (capabilities?.Count == 0 || (currentMediaStream.LocalTrack == null && currentMediaStream.LocalTrack != null && currentMediaStream.LocalTrack.Capabilities?.Count == 0)))
+                    else if (currentMediaStream.MediaType == SDPMediaTypesEnum.video)
                     {
-                        return SetDescriptionResultEnum.VideoIncompatible;
+                        if (capabilities?.Count == 0 || (currentMediaStream.LocalTrack == null && currentMediaStream.LocalTrack != null && currentMediaStream.LocalTrack.Capabilities?.Count == 0))
+                        {
+                            return SetDescriptionResultEnum.VideoIncompatible;
+                        }
                     }
                 }
 
@@ -1459,10 +1462,6 @@ private bool RemoveLocalTrack(MediaStreamTrack track)
                     {
                         RequireRenegotiation = true;
                         textStream.LocalTrack = null;
-
-                        CloseMediaStream("normal", textStream);
-                        IsVideoStarted = false;
-                        TextStreamList.Remove(textStream);
                         return true;
                     }
                 }
@@ -1475,10 +1474,6 @@ private bool RemoveLocalTrack(MediaStreamTrack track)
                     {
                         RequireRenegotiation = true;
                         videoStream.LocalTrack = null;
-
-                        CloseMediaStream("normal", videoStream);
-                        IsVideoStarted = false;
-                        VideoStreamList.Remove(videoStream);
                         return true;
                     }
                 }
@@ -1968,25 +1963,6 @@ private SDP GetSessionDescription(List<MediaStream> mediaStreamList, IPAddress c
                         }
                     }
 
-                    if (localAddress == null)
-                    {
-                        foreach (var textStream in TextStreamList)
-                        {
-                            if (textStream.DestinationEndPoint != null && textStream.DestinationEndPoint.Address != null)
-                            {
-                                if (IPAddress.Any.Equals(textStream.DestinationEndPoint.Address) || IPAddress.IPv6Any.Equals(textStream.DestinationEndPoint.Address))
-                                {
-                                    // If the remote party has set an inactive media stream via the connection address then we do the same.
-                                    localAddress = textStream.DestinationEndPoint.Address;
-                                }
-                                else
-                                {
-                                    localAddress = NetServices.GetLocalAddressForRemote(textStream.DestinationEndPoint.Address);
-                                }
-                            }
-                        }
-                    }
-
                     if (localAddress == null)
                     {
                         if (connectionAddress == IPAddress.IPv6Any && NetServices.InternetDefaultIPv6Address != null)
@@ -2731,6 +2707,10 @@ public void SendRtpRaw(SDPMediaTypesEnum mediaType, byte[] payload, uint timesta
             {
                 VideoStream?.SendRtpRaw(payload, timestamp, markerBit, payloadTypeID);
             }
+            else if (mediaType == SDPMediaTypesEnum.text)
+            {
+                TextStream?.SendRtpRaw(payload, timestamp, markerBit, payloadTypeID);
+            }
         }
 
         /// <summary>
@@ -2819,6 +2799,10 @@ public void SendRtcpTWCCFeedback(SDPMediaTypesEnum mediaType, RTCPTWCCFeedback f
             {
                 VideoStream?.SendRtcpTWCCFeedback(feedback);
             }
+            else if (mediaType == SDPMediaTypesEnum.text)
+            {
+                TextStream?.SendRtcpTWCCFeedback(feedback);
+            }
         }
 
         /// <summary>