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enginex-mr_series-sherpa-onnx/scripts/dotnet/KeywordSpotter.cs
Fangjun Kuang 8b989a851c Fix keyword spotting. (#1689)
Reset the stream right after detecting a keyword
2025-01-20 16:41:10 +08:00

131 lines
4.7 KiB
C#

/// Copyright (c) 2024 Xiaomi Corporation (authors: Fangjun Kuang)
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;
namespace SherpaOnnx
{
// please see
// https://www.mono-project.com/docs/advanced/pinvoke/#gc-safe-pinvoke-code
// https://www.mono-project.com/docs/advanced/pinvoke/#properly-disposing-of-resources
public class KeywordSpotter : IDisposable
{
public KeywordSpotter(KeywordSpotterConfig config)
{
IntPtr h = SherpaOnnxCreateKeywordSpotter(ref config);
_handle = new HandleRef(this, h);
}
public OnlineStream CreateStream()
{
IntPtr p = SherpaOnnxCreateKeywordStream(_handle.Handle);
return new OnlineStream(p);
}
public OnlineStream CreateStream(string keywords)
{
byte[] utf8Bytes = Encoding.UTF8.GetBytes(keywords);
byte[] utf8BytesWithNull = new byte[utf8Bytes.Length + 1]; // +1 for null terminator
Array.Copy(utf8Bytes, utf8BytesWithNull, utf8Bytes.Length);
utf8BytesWithNull[utf8Bytes.Length] = 0; // Null terminator
IntPtr p = SherpaOnnxCreateKeywordStreamWithKeywords(_handle.Handle, utf8BytesWithNull);
return new OnlineStream(p);
}
/// Return true if the passed stream is ready for decoding.
public bool IsReady(OnlineStream stream)
{
return IsReady(_handle.Handle, stream.Handle) != 0;
}
/// You have to ensure that IsReady(stream) returns true before
/// you call this method
public void Decode(OnlineStream stream)
{
Decode(_handle.Handle, stream.Handle);
}
public void Reset(OnlineStream stream)
{
Reset(_handle.Handle, stream.Handle);
}
// The caller should ensure all passed streams are ready for decoding.
public void Decode(IEnumerable<OnlineStream> streams)
{
// TargetFramework=net20 does not support System.Linq
// IntPtr[] ptrs = streams.Select(s => s.Handle).ToArray();
List<IntPtr> list = new List<IntPtr>();
foreach (OnlineStream s in streams)
{
list.Add(s.Handle);
}
IntPtr[] ptrs = list.ToArray();
Decode(_handle.Handle, ptrs, ptrs.Length);
}
public KeywordResult GetResult(OnlineStream stream)
{
IntPtr h = GetResult(_handle.Handle, stream.Handle);
KeywordResult result = new KeywordResult(h);
DestroyResult(h);
return result;
}
public void Dispose()
{
Cleanup();
// Prevent the object from being placed on the
// finalization queue
System.GC.SuppressFinalize(this);
}
~KeywordSpotter()
{
Cleanup();
}
private void Cleanup()
{
SherpaOnnxDestroyKeywordSpotter(_handle.Handle);
// Don't permit the handle to be used again.
_handle = new HandleRef(this, IntPtr.Zero);
}
private HandleRef _handle;
[DllImport(Dll.Filename)]
private static extern IntPtr SherpaOnnxCreateKeywordSpotter(ref KeywordSpotterConfig config);
[DllImport(Dll.Filename)]
private static extern void SherpaOnnxDestroyKeywordSpotter(IntPtr handle);
[DllImport(Dll.Filename)]
private static extern IntPtr SherpaOnnxCreateKeywordStream(IntPtr handle);
[DllImport(Dll.Filename)]
private static extern IntPtr SherpaOnnxCreateKeywordStreamWithKeywords(IntPtr handle, [MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.I1)] byte[] utf8Keywords);
[DllImport(Dll.Filename, EntryPoint = "SherpaOnnxIsKeywordStreamReady")]
private static extern int IsReady(IntPtr handle, IntPtr stream);
[DllImport(Dll.Filename, EntryPoint = "SherpaOnnxDecodeKeywordStream")]
private static extern void Decode(IntPtr handle, IntPtr stream);
[DllImport(Dll.Filename, EntryPoint = "SherpaOnnxResetKeywordStream")]
private static extern void Reset(IntPtr handle, IntPtr stream);
[DllImport(Dll.Filename, EntryPoint = "SherpaOnnxDecodeMultipleKeywordStreams")]
private static extern void Decode(IntPtr handle, IntPtr[] streams, int n);
[DllImport(Dll.Filename, EntryPoint = "SherpaOnnxGetKeywordResult")]
private static extern IntPtr GetResult(IntPtr handle, IntPtr stream);
[DllImport(Dll.Filename, EntryPoint = "SherpaOnnxDestroyKeywordResult")]
private static extern void DestroyResult(IntPtr result);
}
}