Add C API for streaming HLG decoding (#734)

scripts/dotnet/examples/streaming-hlg-decoding.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <RootNamespace>streaming_hlg_decoding</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <RestoreSources>/tmp/packages;$(RestoreSources);https://api.nuget.org/v3/index.json</RestoreSources>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="org.k2fsa.sherpa.onnx" Version="*" />
+  </ItemGroup>
+
+</Project>

scripts/dotnet/online.cs

@@ -116,6 +116,21 @@ namespace SherpaOnnx
     public int FeatureDim;
   }
 
+  [StructLayout(LayoutKind.Sequential)]
+  public struct OnlineCtcFstDecoderConfig
+  {
+    public OnlineCtcFstDecoderConfig()
+    {
+      Graph = "";
+      MaxActive = 3000;
+    }
+
+    [MarshalAs(UnmanagedType.LPStr)]
+    public string Graph;
+
+    public int MaxActive;
+  }
+
   [StructLayout(LayoutKind.Sequential)]
   public struct OnlineRecognizerConfig
   {
@@ -131,6 +146,7 @@ namespace SherpaOnnx
       Rule3MinUtteranceLength = 20.0F;
       HotwordsFile = "";
       HotwordsScore = 1.5F;
+      CtcFstDecoderConfig = new OnlineCtcFstDecoderConfig();
     }
     public FeatureConfig FeatConfig;
     public OnlineModelConfig ModelConfig;
@@ -167,6 +183,8 @@ namespace SherpaOnnx
 
     /// Bonus score for each token in hotwords.
     public float HotwordsScore;
+
+    public OnlineCtcFstDecoderConfig CtcFstDecoderConfig;
   }
 
   public class OnlineRecognizerResult

scripts/go/_internal/streaming-hlg-decoding/.gitignore

@@ -0,0 +1 @@
+streaming-hlg-decoding

scripts/go/_internal/streaming-hlg-decoding/go.mod

@@ -0,0 +1,5 @@
+module streaming-hlg-decoding
+
+go 1.12
+
+replace github.com/k2-fsa/sherpa-onnx-go/sherpa_onnx => ../

scripts/go/_internal/streaming-hlg-decoding/main.go

@@ -0,0 +1 @@
+../../../../go-api-examples/streaming-hlg-decoding/main.go

scripts/go/_internal/streaming-hlg-decoding/run.sh

@@ -0,0 +1 @@
+../../../../go-api-examples/streaming-hlg-decoding/run.sh

scripts/go/sherpa_onnx.go

@@ -99,6 +99,11 @@ type FeatureConfig struct {
 	FeatureDim int
 }
 
+type OnlineCtcFstDecoderConfig struct {
+	Graph     string
+	MaxActive int
+}
+
 // Configuration for the online/streaming recognizer.
 type OnlineRecognizerConfig struct {
 	FeatConfig  FeatureConfig
@@ -120,6 +125,7 @@ type OnlineRecognizerConfig struct {
 	Rule1MinTrailingSilence float32
 	Rule2MinTrailingSilence float32
 	Rule3MinUtteranceLength float32
+	CtcFstDecoderConfig     OnlineCtcFstDecoderConfig
 }
 
 // It contains the recognition result for a online stream.
@@ -190,6 +196,10 @@ func NewOnlineRecognizer(config *OnlineRecognizerConfig) *OnlineRecognizer {
 	c.rule2_min_trailing_silence = C.float(config.Rule2MinTrailingSilence)
 	c.rule3_min_utterance_length = C.float(config.Rule3MinUtteranceLength)
 
+	c.ctc_fst_decoder_config.graph = C.CString(config.CtcFstDecoderConfig.Graph)
+	defer C.free(unsafe.Pointer(c.ctc_fst_decoder_config.graph))
+	c.ctc_fst_decoder_config.max_active = C.int(config.CtcFstDecoderConfig.MaxActive)
+
 	recognizer := &OnlineRecognizer{}
 	recognizer.impl = C.CreateOnlineRecognizer(&c)