Use TagLib# to keep MP3 data separate from AAC.

src/sc_bridge/ShoutcastBridge.csproj

@@ -48,11 +48,17 @@
     <Reference Include="Newtonsoft.Json">
       <HintPath>..\..\packages\Newtonsoft.Json.6.0.3\lib\net45\Newtonsoft.Json.dll</HintPath>
     </Reference>
+    <Reference Include="policy.2.0.taglib-sharp">
+      <HintPath>..\..\packages\taglib.2.1.0.0\lib\policy.2.0.taglib-sharp.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Web" />
     <Reference Include="System.XML" />
     <Reference Include="System.Xml.Linq" />
+    <Reference Include="taglib-sharp">
+      <HintPath>..\..\packages\taglib.2.1.0.0\lib\taglib-sharp.dll</HintPath>
+    </Reference>
     <Reference Include="uhttpsharp">
       <HintPath>..\..\packages\uHttpSharp.0.1.4.7\lib\net40\uhttpsharp.dll</HintPath>
     </Reference>

src/sc_bridge/ShoutcastBridgeServer.cs

@@ -1,12 +1,16 @@
-using log4net;
+using System.IO;
+using log4net;
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Sockets;
+using TagLib;
+using TagLib.Aac;
 using uhttpsharp;
 using uhttpsharp.Listeners;
 using uhttpsharp.RequestProviders;
+using File = System.IO.File;
 
 namespace AFR.ShoutcastBridge
 {
@@ -164,21 +168,49 @@ namespace AFR.ShoutcastBridge
                             icecast.Url = shoutcast.StreamUrl;
                             icecast.Public = shoutcast.StreamPublic;
                             if (icecast.ContentType == "undefined")
-                                switch (BitConverter.ToString(data.Take(2).ToArray()).Replace("-", "").ToLower())
+                            {
+                                var fmtcode = BitConverter.ToString(data.Take(2).ToArray()).Replace("-", "").ToLower();
+                                switch (fmtcode)
                                 {
                                     case "4f67": // OGG container
                                         _sourcelog.DebugFormat("[{0}] Detected OGG audio container", srs.ClientEndPoint);
                                         icecast.ContentType = "audio/ogg";
                                         break;
-                                    case "fff9": // AAC
-                                        _sourcelog.DebugFormat("[{0}] Detected AAC-LC data", srs.ClientEndPoint);
-                                        icecast.ContentType = "audio/aac";
-                                        break;
                                     default:
-                                        _sourcelog.DebugFormat("[{0}] Assuming MP3 codec", srs.ClientEndPoint);
+
-                                        icecast.ContentType = "audio/mpeg";
+                                        var testpath = Path.GetTempFileName() + ".mp3"; // Will make TagLib try to parse the file as MP3
+                                        try
+                                        {
+                                            using (var fs = File.Open(testpath, FileMode.OpenOrCreate))
+                                            {
+                                                fs.Write(data, 0, data.Length);
+                                                fs.Flush();
+                                            }
+                                        }
+                                        catch (Exception err)
+                                        {
+                                            _sourcelog.ErrorFormat("[{0}] Failed writing temporary data for analysis: {1}", srs.ClientEndPoint, err);
+                                            throw;
+                                        }
+
+                                        try
+                                        {
+                                            var f = TagLib.File.Create(testpath);
+                                            if (f.PossiblyCorrupt)
+                                                throw new Exception();
+
+                                            _sourcelog.DebugFormat("[{0}] Detected MP3 codec", srs.ClientEndPoint);
+                                            icecast.ContentType = f.MimeType;
+                                            File.Delete(testpath);
+                                        }
+                                        catch
+                                        {
+                                            _sourcelog.DebugFormat("[{0}] Assuming AAC codec", srs.ClientEndPoint);
+                                            icecast.ContentType = "audio/aac";
+                                        }
                                         break;
                                 }
+                            }
                             if (!icecast.Open())
                             {
                                 _sourcelog.ErrorFormat("[{0}] Could not connect with Icecast, retrying on next packet", srs.ClientEndPoint);

src/sc_bridge/ShoutcastReadingStream.cs

@@ -109,7 +109,7 @@ namespace AFR.ShoutcastBridge
             }
 
             // Content
-            var data = new byte[2048];
+            var data = new byte[16 * 1024];
             try
             {
                 int length;

src/sc_bridge/packages.config

@@ -2,5 +2,6 @@
 <packages>
   <package id="log4net" version="2.0.3" targetFramework="net45" />
   <package id="Newtonsoft.Json" version="6.0.3" targetFramework="net45" />
+  <package id="taglib" version="2.1.0.0" targetFramework="net45" />
   <package id="uHttpSharp" version="0.1.4.7" targetFramework="net45" />
 </packages>