Add C# API for Moonshine models. (#1483)

* Also, return timestamps for non-streaming ASR.

scripts/dotnet/OfflineModelConfig.cs

@@ -24,6 +24,7 @@ namespace SherpaOnnx
             BpeVocab = "";
             TeleSpeechCtc = "";
             SenseVoice = new OfflineSenseVoiceModelConfig();
+            Moonshine = new OfflineMoonshineModelConfig();
         }
         public OfflineTransducerModelConfig Transducer;
         public OfflineParaformerModelConfig Paraformer;
@@ -54,5 +55,6 @@ namespace SherpaOnnx
         public string TeleSpeechCtc;
 
         public OfflineSenseVoiceModelConfig SenseVoice;
+        public OfflineMoonshineModelConfig Moonshine;
     }
 }

scripts/dotnet/OfflineMoonshineModelConfig.cs

@@ -0,0 +1,29 @@
+/// Copyright (c)  2024  Xiaomi Corporation (authors: Fangjun Kuang)
+
+using System.Runtime.InteropServices;
+
+namespace SherpaOnnx
+{
+    [StructLayout(LayoutKind.Sequential)]
+    public struct OfflineMoonshineModelConfig
+    {
+        public OfflineMoonshineModelConfig()
+        {
+            Preprocessor = "";
+            Encoder = "";
+            UncachedDecoder = "";
+            CachedDecoder = "";
+        }
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string Preprocessor;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string Encoder;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string UncachedDecoder;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string CachedDecoder;
+    }
+}

scripts/dotnet/OfflineRecognizerResult.cs

@@ -31,17 +31,70 @@ namespace SherpaOnnx
             byte[] stringBuffer = new byte[length];
             Marshal.Copy(impl.Text, stringBuffer, 0, length);
             _text = Encoding.UTF8.GetString(stringBuffer);
+
+            _tokens = new String[impl.Count];
+
+            unsafe
+            {
+                byte* buf = (byte*)impl.Tokens;
+                for (int i = 0; i < impl.Count; i++)
+                {
+                    length = 0;
+                    byte* start = buf;
+                    while (*buf != 0)
+                    {
+                        ++buf;
+                        length += 1;
+                    }
+                    ++buf;
+
+                    stringBuffer = new byte[length];
+                    fixed (byte* pTarget = stringBuffer)
+                    {
+                        for (int k = 0; k < length; k++)
+                        {
+                            pTarget[k] = start[k];
+                        }
+                    }
+
+                    _tokens[i] = Encoding.UTF8.GetString(stringBuffer);
+                }
+            }
+
+            unsafe
+            {
+              if (impl.Timestamps != IntPtr.Zero)
+              {
+                float *t = (float*)impl.Timestamps;
+                _timestamps = new float[impl.Count];
+                fixed (float* f = _timestamps)
+                {
+                  for (int k = 0; k < impl.Count; k++)
+                  {
+                    f[k] = t[k];
+                  }
+                }
+              }
+            }
+
         }
 
         [StructLayout(LayoutKind.Sequential)]
         struct Impl
         {
             public IntPtr Text;
+            public IntPtr Timestamps;
+            public int Count;
+            public IntPtr Tokens;
         }
 
         private String _text;
         public String Text => _text;
+
+        private String[] _tokens;
+        public String[] Tokens => _tokens;
+
+        private float[] _timestamps;
+        public float[] Timestamps => _timestamps;
     }
-
-
 }