Reading SDT, PAT

nilaoda · Nov 13, 2021 · 32b1d4b · 32b1d4b
1 parent 1afadb7
commit 32b1d4b
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Showing 2 changed files with 85 additions and 2 deletions.
diff --git a/RtspRecorder/RTSPClient.cs b/RtspRecorder/RTSPClient.cs
@@ -25,6 +25,10 @@ internal class RTSPClient
         public string OutName { get; set; }
         public int RecDurLimit { get; set; } = 0;
         private TcpClient client;
+        private string title = "";
+        private string programId = "";
+        private string serviceProvider = "";
+        private string serviceName = "";
 
         private RTSPClient()
         {
@@ -62,6 +66,14 @@ private void LogResp(object text)
             Console.WriteLine();
         }
 
+        private void LogTsInfo(object text)
+        {
+            Console.ForegroundColor = ConsoleColor.Cyan;
+            Console.Write(text);
+            Console.ResetColor();
+            Console.WriteLine();
+        }
+
         public void Connect()
         {
             if (client != null && client.Connected) 
@@ -96,7 +108,7 @@ private void StartTimer()
                 var size = Util.FormatFileSize(streamSize);
                 if (streamSize != streamSizeLast)
                 {
-                    if (!StdOut) Console.Write("\rReceiving... [" + Util.FormatTime(recCount) + $"] [{size}]" + "".PadRight(6));
+                    if (!StdOut) Console.Write("\rReceiving... " + (string.IsNullOrEmpty(this.title) ? "" : $"[{this.title}] ") + "[" + Util.FormatTime(recCount) + $"] [{size}]" + "".PadRight(6));
                     streamSizeLast = streamSize;
                 }
                 else
@@ -136,6 +148,10 @@ public void DoWork()
             {
                 this.url = Regex.Match(resp2str, "Content-Base: (.*)").Groups[1].Value.Trim();
             }
+            if (Regex.IsMatch(resp2str, "s=(.*)"))
+            {
+                this.title = Regex.Match(resp2str, "s=(.*)").Groups[1].Value.Trim();
+            }
 
 
             //3.SETUP
@@ -184,6 +200,7 @@ public void DoWork()
              *            | $ | id | Length |
              *            -------------------
              */
+            var infoBuffer = new List<byte>(188 * 5000); //5000个分包中解析信息，没有就算了
             while (true && !stopFlag) 
             {
                 if (reader.ReadByte() == 0x24) //遇到4字节头
@@ -196,6 +213,20 @@ public void DoWork()
                             Array.Reverse(arr);
                         int length = BitConverter.ToUInt16(arr, 0);
                         var data = reader.ReadBytes(length); //TS data
+                        if (infoBuffer.Count < 188 * 5000)
+                        {
+                            infoBuffer.AddRange(data);
+                        }
+                        else if (this.programId == "") 
+                        {
+                            this.ParseTsInfo(infoBuffer.ToArray()); //Parse Info
+                            var info = $"Program {this.programId}"
+                                + ((!string.IsNullOrEmpty(this.serviceName) || !string.IsNullOrEmpty(this.serviceProvider)) ? "\r\n  Metadata:" : "")
+                                + (!string.IsNullOrEmpty(this.serviceName) ? $"\r\n    service_name    :  {this.serviceName}" : "")
+                                + (!string.IsNullOrEmpty(this.serviceProvider) ? $"\r\n    service_provider:  {this.serviceProvider}" : "");
+                            if (this.programId != "") LogTsInfo(info);
+                            else infoBuffer.Clear();
+                        }
                         bufferWriter.Write(data);
                         streamSize += data.Length;
                     }
@@ -204,6 +235,58 @@ public void DoWork()
             bufferWriter.Flush();
         }
 
+        /// <summary>
+        /// Parsing SDT and PAT
+        //  Reference: https://en.wikipedia.org/wiki/MPEG_transport_stream
+        //             https://en.wikipedia.org/wiki/Service_Description_Table
+        //             https://www.etsi.org/deliver/etsi_en/300400_300499/300468/01.03.01_60/en_300468v010301p.pdf
+        /// </summary>
+        private void ParseTsInfo(byte[] data)
+        {
+            UInt16 ConvertToUint16(IEnumerable<byte> bytes)
+            {
+                if (BitConverter.IsLittleEndian)
+                    bytes = bytes.Reverse();
+                return BitConverter.ToUInt16(bytes.ToArray());
+            }
+
+            for (int i = 0; i < data.Length; i++)
+            {
+                if (data[i] == 0x47 && (i + 188) < data.Length && data[i + 188] == 0x47)
+                {
+                    var tsData = data.Skip(i).Take(188);
+                    var tsHeaderInt = BitConverter.ToUInt32(BitConverter.IsLittleEndian ? tsData.Take(4).Reverse().ToArray() : tsData.Take(4).ToArray(), 0);
+                    var pid = (tsHeaderInt & 0x1fff00) >> 8;
+                    var tsPayload = tsData.Skip(4);
+                    //PAT
+                    if (pid == 0x0000)
+                    {
+                        this.programId = ConvertToUint16(tsPayload.Skip(9).Take(2)).ToString();
+                    }
+                    //SDT, BAT, ST
+                    else if (pid == 0x0011)
+                    {
+                        var tableId = (int)tsPayload.Skip(1).First();
+                        //Current TS Info
+                        if (tableId == 0x42)
+                        {
+                            var sectionLength = ConvertToUint16(tsPayload.Skip(2).Take(2)) & 0xfff;
+                            var sectionData = tsPayload.Skip(4).Take(sectionLength);
+                            var dscripData = sectionData.Skip(8);
+                            var descriptorsLoopLength = (ConvertToUint16(dscripData.Skip(3).Take(2))) & 0xfff;
+                            var descriptorsData = dscripData.Skip(5).Take(descriptorsLoopLength);
+                            var serviceProviderLength = (int)descriptorsData.Skip(3).First();
+                            this.serviceProvider = Encoding.UTF8.GetString(descriptorsData.Skip(4).Take(serviceProviderLength).ToArray());
+                            var serviceNameLength = (int)descriptorsData.Skip(4 + serviceProviderLength).First();
+                            this.serviceName = Encoding.UTF8.GetString(descriptorsData.Skip(5 + serviceProviderLength).Take(serviceNameLength).ToArray());
+                        }
+                    }
+                    if (this.programId != "" && (this.serviceName != "" || this.serviceProvider != ""))
+                        break;
+                }
+            }
+        }
+
         public void Close()
         {
             if (client.Connected)

diff --git a/RtspRecorder/RtspRecorder.csproj b/RtspRecorder/RtspRecorder.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <Version>1.1.0</Version>
+    <Version>1.2.0</Version>
     <OutputType>Exe</OutputType>
     <TargetFramework>net6.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>