B Fixed keepalive OPTIONS message not having session/uri, added basic RTCP Receiver report

Author: jimm98y

src/Directory.Build.props

@@ -5,7 +5,7 @@
 		<Nullable>disable</Nullable>
 		<ImplicitUsings>disable</ImplicitUsings>
 		<Title>$(ProjectName)</Title>
-		<Version>0.1.2</Version>
+		<Version>0.1.3</Version>
 		<Authors>Lukas Volf</Authors>
 		<Copyright>MIT</Copyright>
 		<PackageProjectUrl>https://github.com/jimm98y/SharpRealTimeStreaming</PackageProjectUrl>

src/SharpRTSPClient/Directory.Build.props

@@ -0,0 +1,33 @@
+<Project>
+	<PropertyGroup>
+		<GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+		<AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+		<Nullable>disable</Nullable>
+		<ImplicitUsings>disable</ImplicitUsings>
+		<Title>$(ProjectName)</Title>
+		<Version>0.1.2</Version>
+		<Authors>Lukas Volf</Authors>
+		<Copyright>MIT</Copyright>
+		<PackageProjectUrl>https://github.com/jimm98y/SharpRealTimeStreaming</PackageProjectUrl>
+		<PackageReadmeFile>README.md</PackageReadmeFile>
+		<RepositoryUrl>https://github.com/jimm98y/SharpRealTimeStreaming</RepositoryUrl>
+		<RepositoryType>git</RepositoryType>
+		<PackageTags>rtsp;rtp;video;streaming;h264;h265;aac;netstandard20</PackageTags>
+		<NeutralLanguage>en-US</NeutralLanguage>
+		<AssemblyVersion>1.0.0</AssemblyVersion>
+		<FileVersion>$(Version)</FileVersion>
+		<PackageLicenseExpression>MIT</PackageLicenseExpression>
+		<Description>Simple RTSP client and server. Supports H264, H265 and AAC.</Description>
+	</PropertyGroup>
+	
+	<ItemGroup>
+		<None Include="..\..\README.md">
+			<Pack>True</Pack>
+			<PackagePath>\</PackagePath>
+		</None>
+	</ItemGroup>
+
+	<PropertyGroup>
+		<PackageOutputPath>$(ProjectDir)..\..\nugets</PackageOutputPath>
+	</PropertyGroup>
+</Project>

src/SharpRTSPClient/RTSPClient.cs

@@ -531,6 +531,28 @@ public void SendAudioRTCP(byte[] rtcp)
             _audioRtpTransport.WriteToControlPort(rtcp);
         }
 
+        public byte[] BuildRtcpReceiverReport(uint ssrc)
+        {
+            // TODO: do not send just an empty report
+            // https://www.rfc-editor.org/rfc/rfc3550.txt
+            // https://learn.microsoft.com/en-us/openspecs/office_protocols/ms-rtp/953b588a-4e9d-4ec8-b4d1-913f9b9d04ef
+            byte[] rtcp_receiver_report = new byte[8];
+            int version = 2;
+            int paddingBit = 0;
+            int reportCount = 0; // an empty report
+            int packetType = 201; // Receiver Report
+            int length = rtcp_receiver_report.Length / 4 - 1; // num 32 bit words minus 1
+            rtcp_receiver_report[0] = (byte)((version << 6) + (paddingBit << 5) + reportCount);
+            rtcp_receiver_report[1] = (byte)packetType;
+            rtcp_receiver_report[2] = (byte)(length >> 8 & 0xFF);
+            rtcp_receiver_report[3] = (byte)(length >> 0 & 0XFF);
+            rtcp_receiver_report[4] = (byte)(ssrc >> 24 & 0xFF);
+            rtcp_receiver_report[5] = (byte)(ssrc >> 16 & 0xFF);
+            rtcp_receiver_report[6] = (byte)(ssrc >> 8 & 0xFF);
+            rtcp_receiver_report[7] = (byte)(ssrc >> 0 & 0xFF);
+            return rtcp_receiver_report;
+        }
+
         private void VideoRtpDataReceived(object sender, RtspDataEventArgs e)
         {
             if (e.Data.Data.IsEmpty)
@@ -1342,7 +1364,10 @@ private void SendKeepAlive(object sender, System.Timers.ElapsedEventArgs e)
             else
             {
                 keepAliveMessage = new RtspRequestOptions
-                { };
+                { 
+                    RtspUri = _uri,
+                    Session = _session
+                };
             }
 
             keepAliveMessage.AddAuthorization(_authentication, _uri, _rtspSocket.NextCommandIndex());