--- OniSplit/Sound/SoundData.cs	2020/05/28 21:28:44	1130
+++ OniSplit/Sound/SoundData.cs	2020/05/30 12:08:12	1131
@@ -11,7 +11,7 @@ namespace Oni.Sound
         public int ChannelCount;
         public byte[] Data;
 
-        public static SoundData Read(InstanceDescriptor sndd)
+        public static SoundData Read(InstanceDescriptor sndd, bool do_pc_demo_test)
         {
             if (sndd.Template.Tag != TemplateTag.SNDD)
                 throw new ArgumentException("descriptor");
@@ -46,6 +46,28 @@ namespace Oni.Sound
             using (var rawReader = sndd.GetRawReader(dataOffset))
                 sound.Data = rawReader.ReadBytes(dataSize);
 
+            if (sound.IsIMA4 && do_pc_demo_test) // check if the raw data actually looks like IMA4
+            {
+                int nIMABlocks = sound.Data.Length / 34;
+                int remainder = sound.Data.Length - nIMABlocks * 34;
+                if (remainder == 0 && (nIMABlocks % sound.ChannelCount) == 0)
+                {
+                    bool stepIndexAbove88 = false;
+                    for (int ii = 0; ii < nIMABlocks; ii++)
+                    {
+                        Byte cc = sound.Data[ii * 34 + 1];
+                        if ((cc & 0x7F) > 88)
+                            stepIndexAbove88 = true;
+                    }
+                    if (stepIndexAbove88)
+                        sound.IsIMA4 = false;
+                }
+                else
+                    sound.IsIMA4 = false;
+                if (!(sound.IsIMA4))
+                    Console.WriteLine("PC-demo MS ADPCM detected; use -nodemo flag to treat as IMA4.");
+            }
+
             return sound;
         }
     }