--- OniSplit/Sound/SoundData.cs	2020/01/22 14:08:57	1114
+++ OniSplit/Sound/SoundData.cs	2020/05/30 12:08:12	1131
@@ -6,11 +6,12 @@ namespace Oni.Sound
 {
     internal class SoundData
     {
+        public bool IsIMA4;
         public int SampleRate;
         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");
@@ -27,13 +28,15 @@ namespace Oni.Sound
                     sound.ChannelCount = (reader.ReadInt32() >> 1) + 1;
                     sound.SampleRate = 22050;
                     reader.Skip(4);
+                    sound.IsIMA4 = true;
                 }
                 else
                 {
-                    reader.Skip(6);
+                    reader.Skip(6); // ADPCM format identifiers (change to support PCM?)
                     sound.ChannelCount = reader.ReadInt16();
                     sound.SampleRate = reader.ReadInt32();
                     reader.Skip(44);
+                    sound.IsIMA4 = false;
                 }
 
                 dataSize = reader.ReadInt32();
@@ -43,6 +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;
         }
     }