Add CTC HLG decoding for JNI (#810)

.github/workflows/jni.yaml

@@ -37,7 +37,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-latest, macos-latest, macos-14]
 
     steps:
       - uses: actions/checkout@v4
@@ -49,6 +49,11 @@ jobs:
         with:
           key: ${{ matrix.os }}
 
+      - name: OS info
+        shell: bash
+        run: |
+          uname -a
+
       - name: Display kotlin version
         shell: bash
         run: |
@@ -58,6 +63,7 @@ jobs:
         shell: bash
         run: |
           java -version
+          javac -help
           echo "JAVA_HOME is: ${JAVA_HOME}"
 
       - name:  Run JNI test

.github/workflows/run-java-test.yaml

@@ -38,7 +38,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest]
+        os: [ubuntu-latest, macos-latest, macos-14]
 
     steps:
       - uses: actions/checkout@v4
@@ -50,10 +50,24 @@ jobs:
         with:
           key: ${{ matrix.os }}-java
 
+      - name: OS info
+        shell: bash
+        run: |
+          uname -a
+
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin' # See 'Supported distributions' for available options
+          java-version: '21'
+
       - name: Display java version
         shell: bash
         run: |
           java -version
+          java -help
+          echo "----"
+          javac -version
+          javac -help
           echo "JAVA_HOME is: ${JAVA_HOME}"
 
           cmake --version
@@ -100,6 +114,9 @@ jobs:
           # Delete model files to save space
           rm -rf sherpa-onnx-streaming-*
 
+          ./run-streaming-decode-file-ctc-hlg.sh
+          rm -rf sherpa-onnx-streaming-*
+
           ./run-streaming-decode-file-paraformer.sh
           rm -rf sherpa-onnx-streaming-*
 
@@ -118,3 +135,6 @@ jobs:
 
           ./run-non-streaming-decode-file-whisper.sh
           rm -rf sherpa-onnx-whisper-*
+
+          ./run-non-streaming-decode-file-nemo.sh
+          rm -rf sherpa-onnx-nemo-*

dotnet-examples/offline-tts-play/offline-tts-play.csproj

@@ -8,10 +8,6 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
-  <PropertyGroup>
-    <RestoreSources>/tmp/packages;$(RestoreSources);https://api.nuget.org/v3/index.json</RestoreSources>
-  </PropertyGroup>
-
   <ItemGroup>
     <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="org.k2fsa.sherpa.onnx" Version="*" />

java-api-examples/NonStreamingDecodeFileNemo.java

@@ -0,0 +1,49 @@
+// Copyright 2024 Xiaomi Corporation
+
+// This file shows how to use an offline NeMo CTC model, i.e., non-streaming NeMo CTC model,,
+// to decode files.
+import com.k2fsa.sherpa.onnx.*;
+
+public class NonStreamingDecodeFileNemo {
+  public static void main(String[] args) {
+    // please refer to
+    // https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+    // to download model files
+    String model = "./sherpa-onnx-nemo-ctc-en-citrinet-512/model.int8.onnx";
+    String tokens = "./sherpa-onnx-nemo-ctc-en-citrinet-512/tokens.txt";
+
+    String waveFilename = "./sherpa-onnx-nemo-ctc-en-citrinet-512/test_wavs/1.wav";
+
+    WaveReader reader = new WaveReader(waveFilename);
+
+    OfflineNemoEncDecCtcModelConfig nemo =
+        OfflineNemoEncDecCtcModelConfig.builder().setModel(model).build();
+
+    OfflineModelConfig modelConfig =
+        OfflineModelConfig.builder()
+            .setNemo(nemo)
+            .setTokens(tokens)
+            .setNumThreads(1)
+            .setDebug(true)
+            .build();
+
+    OfflineRecognizerConfig config =
+        OfflineRecognizerConfig.builder()
+            .setOfflineModelConfig(modelConfig)
+            .setDecodingMethod("greedy_search")
+            .build();
+
+    OfflineRecognizer recognizer = new OfflineRecognizer(config);
+    OfflineStream stream = recognizer.createStream();
+    stream.acceptWaveform(reader.getSamples(), reader.getSampleRate());
+
+    recognizer.decode(stream);
+
+    String text = recognizer.getResult(stream).getText();
+
+    System.out.printf("filename:%s\nresult:%s\n", waveFilename, text);
+
+    stream.release();
+    recognizer.release();
+  }
+}

java-api-examples/README.md

@@ -8,6 +8,7 @@ This directory contains examples for the JAVA API of sherpa-onnx.
 
 ```
 ./run-streaming-decode-file-ctc.sh
+./run-streaming-decode-file-ctc-hlg.sh
 ./run-streaming-decode-file-paraformer.sh
 ./run-streaming-decode-file-transducer.sh
 ```
@@ -18,4 +19,5 @@ This directory contains examples for the JAVA API of sherpa-onnx.
 ./run-non-streaming-decode-file-paraformer.sh
 ./run-non-streaming-decode-file-transducer.sh
 ./run-non-streaming-decode-file-whisper.sh
+./run-non-streaming-decode-file-nemo.sh
 ```

java-api-examples/StreamingDecodeFileCtcHLG.java

@@ -0,0 +1,58 @@
+// Copyright 2024 Xiaomi Corporation
+
+// This file shows how to use an online CTC model, i.e., streaming CTC model,
+// to decode files.
+import com.k2fsa.sherpa.onnx.*;
+
+public class StreamingDecodeFileCtcHLG {
+  public static void main(String[] args) {
+    // please refer to
+    // https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+    // to download model files
+    String model =
+        "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/ctc-epoch-30-avg-3-chunk-16-left-128.int8.onnx";
+    String tokens = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/tokens.txt";
+    String hlg = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/HLG.fst";
+    String waveFilename = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/test_wavs/8k.wav";
+
+    WaveReader reader = new WaveReader(waveFilename);
+
+    OnlineZipformer2CtcModelConfig ctc =
+        OnlineZipformer2CtcModelConfig.builder().setModel(model).build();
+
+    OnlineModelConfig modelConfig =
+        OnlineModelConfig.builder()
+            .setZipformer2Ctc(ctc)
+            .setTokens(tokens)
+            .setNumThreads(1)
+            .setDebug(true)
+            .build();
+
+    OnlineCtcFstDecoderConfig ctcFstDecoderConfig =
+        OnlineCtcFstDecoderConfig.builder().setGraph("hlg").build();
+
+    OnlineRecognizerConfig config =
+        OnlineRecognizerConfig.builder()
+            .setOnlineModelConfig(modelConfig)
+            .setCtcFstDecoderConfig(ctcFstDecoderConfig)
+            .build();
+
+    OnlineRecognizer recognizer = new OnlineRecognizer(config);
+    OnlineStream stream = recognizer.createStream();
+    stream.acceptWaveform(reader.getSamples(), reader.getSampleRate());
+
+    float[] tailPaddings = new float[(int) (0.3 * reader.getSampleRate())];
+    stream.acceptWaveform(tailPaddings, reader.getSampleRate());
+
+    while (recognizer.isReady(stream)) {
+      recognizer.decode(stream);
+    }
+
+    String text = recognizer.getResult(stream).getText();
+
+    System.out.printf("filename:%s\nresult:%s\n", waveFilename, text);
+
+    stream.release();
+    recognizer.release();
+  }
+}

java-api-examples/run-non-streaming-decode-file-nemo.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if [[ ! -f ../build/lib/libsherpa-onnx-jni.dylib  && ! -f ../build/lib/libsherpa-onnx-jni.so ]]; then
+  mkdir -p ../build
+  pushd ../build
+  cmake \
+    -DSHERPA_ONNX_ENABLE_PYTHON=OFF \
+    -DSHERPA_ONNX_ENABLE_TESTS=OFF \
+    -DSHERPA_ONNX_ENABLE_CHECK=OFF \
+    -DBUILD_SHARED_LIBS=ON \
+    -DSHERPA_ONNX_ENABLE_PORTAUDIO=OFF \
+    -DSHERPA_ONNX_ENABLE_JNI=ON \
+    ..
+
+  make -j4
+  ls -lh lib
+  popd
+fi
+
+if [ ! -f ../sherpa-onnx/java-api/build/sherpa-onnx.jar ]; then
+  pushd ../sherpa-onnx/java-api
+  make
+  popd
+fi
+
+if [[ ! -f ../build/lib/libsherpa-onnx-jni.dylib  && ! -f ../build/lib/libsherpa-onnx-jni.so ]]; then
+  cmake \
+    -DSHERPA_ONNX_ENABLE_PYTHON=OFF \
+    -DSHERPA_ONNX_ENABLE_TESTS=OFF \
+    -DSHERPA_ONNX_ENABLE_CHECK=OFF \
+    -DBUILD_SHARED_LIBS=ON \
+    -DSHERPA_ONNX_ENABLE_PORTAUDIO=OFF \
+    -DSHERPA_ONNX_ENABLE_JNI=ON \
+    ..
+
+  make -j4
+  ls -lh lib
+fi
+
+if [ ! -f ./sherpa-onnx-nemo-ctc-en-citrinet-512/tokens.txt ]; then
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+  tar xvf sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+  rm sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+fi
+
+java \
+  -Djava.library.path=$PWD/../build/lib \
+  -cp ../sherpa-onnx/java-api/build/sherpa-onnx.jar \
+  NonStreamingDecodeFileNemo.java

java-api-examples/run-streaming-decode-file-ctc-hlg.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+set -ex
+
+if [[ ! -f ../build/lib/libsherpa-onnx-jni.dylib  && ! -f ../build/lib/libsherpa-onnx-jni.so ]]; then
+  mkdir -p ../build
+  pushd ../build
+  cmake \
+    -DSHERPA_ONNX_ENABLE_PYTHON=OFF \
+    -DSHERPA_ONNX_ENABLE_TESTS=OFF \
+    -DSHERPA_ONNX_ENABLE_CHECK=OFF \
+    -DBUILD_SHARED_LIBS=ON \
+    -DSHERPA_ONNX_ENABLE_PORTAUDIO=OFF \
+    -DSHERPA_ONNX_ENABLE_JNI=ON \
+    ..
+
+  make -j4
+  ls -lh lib
+  popd
+fi
+
+if [ ! -f ../sherpa-onnx/java-api/build/sherpa-onnx.jar ]; then
+  pushd ../sherpa-onnx/java-api
+  make
+  popd
+fi
+
+if [ ! -f ./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/tokens.txt ]; then
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+  tar xvf sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+  rm sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+fi
+
+java \
+  -Djava.library.path=$PWD/../build/lib \
+  -cp ../sherpa-onnx/java-api/build/sherpa-onnx.jar \
+  StreamingDecodeFileCtcHLG.java

kotlin-api-examples/run.sh

@@ -69,6 +69,12 @@ function testOnlineAsr() {
     rm sherpa-onnx-streaming-zipformer-ctc-multi-zh-hans-2023-12-13.tar.bz2
   fi
 
+  if [ ! -d ./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18 ]; then
+    curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+    tar xvf sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+    rm sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18.tar.bz2
+  fi
+
   out_filename=test_online_asr.jar
   kotlinc-jvm -include-runtime -d $out_filename \
     test_online_asr.kt \
@@ -160,6 +166,24 @@ function testOfflineAsr() {
     rm sherpa-onnx-whisper-tiny.en.tar.bz2
   fi
 
+  if [ ! -f ./sherpa-onnx-nemo-ctc-en-citrinet-512/tokens.txt ]; then
+    curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+    tar xvf sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+    rm sherpa-onnx-nemo-ctc-en-citrinet-512.tar.bz2
+  fi
+
+  if [ ! -f ./sherpa-onnx-paraformer-zh-2023-03-28/tokens.txt ]; then
+    curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-paraformer-zh-2023-03-28.tar.bz2
+    tar xvf sherpa-onnx-paraformer-zh-2023-03-28.tar.bz2
+    rm sherpa-onnx-paraformer-zh-2023-03-28.tar.bz2
+  fi
+
+  if [ ! -f ./sherpa-onnx-zipformer-multi-zh-hans-2023-9-2/tokens.txt ]; then
+    curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-zipformer-multi-zh-hans-2023-9-2.tar.bz2
+    tar xvf sherpa-onnx-zipformer-multi-zh-hans-2023-9-2.tar.bz2
+    rm sherpa-onnx-zipformer-multi-zh-hans-2023-9-2.tar.bz2
+  fi
+
   out_filename=test_offline_asr.jar
   kotlinc-jvm -include-runtime -d $out_filename \
     test_offline_asr.kt \

kotlin-api-examples/test_offline_asr.kt

@@ -1,12 +1,25 @@
 package com.k2fsa.sherpa.onnx
 
 fun main() {
-  val recognizer = createOfflineRecognizer()
+  val types = arrayOf(0, 2, 5, 6)
+  for (type in types) {
+    test(type)
+  }
+}
 
-  val waveFilename = "./sherpa-onnx-streaming-zipformer-en-20M-2023-02-17/test_wavs/0.wav"
+fun test(type: Int) {
+  val recognizer = createOfflineRecognizer(type)
+
+  val waveFilename = when (type) {
+    0 -> "./sherpa-onnx-paraformer-zh-2023-03-28/test_wavs/0.wav"
+    2 -> "./sherpa-onnx-whisper-tiny.en/test_wavs/0.wav"
+    5 -> "./sherpa-onnx-zipformer-multi-zh-hans-2023-9-2/test_wavs/1.wav"
+    6 -> "./sherpa-onnx-nemo-ctc-en-citrinet-512/test_wavs/8k.wav"
+    else -> null
+  }
 
   val objArray = WaveReader.readWaveFromFile(
-      filename = waveFilename,
+      filename = waveFilename!!,
   )
   val samples: FloatArray = objArray[0] as FloatArray
   val sampleRate: Int = objArray[1] as Int
@@ -22,10 +35,10 @@ fun main() {
   recognizer.release()
 }
 
-fun createOfflineRecognizer(): OfflineRecognizer {
+fun createOfflineRecognizer(type: Int): OfflineRecognizer {
   val config = OfflineRecognizerConfig(
       featConfig = getFeatureConfig(sampleRate = 16000, featureDim = 80),
-      modelConfig = getOfflineModelConfig(type = 2)!!,
+      modelConfig = getOfflineModelConfig(type = type)!!,
   )
 
   return OfflineRecognizer(config = config)

kotlin-api-examples/test_online_asr.kt

@@ -3,6 +3,7 @@ package com.k2fsa.sherpa.onnx
 fun main() {
   testOnlineAsr("transducer")
   testOnlineAsr("zipformer2-ctc")
+  testOnlineAsr("ctc-hlg")
 }
 
 fun testOnlineAsr(type: String) {
@@ -11,6 +12,7 @@ fun testOnlineAsr(type: String) {
         featureDim = 80,
     )
 
+    var ctcFstDecoderConfig  = OnlineCtcFstDecoderConfig()
     val waveFilename: String
     val modelConfig: OnlineModelConfig = when (type) {
       "transducer" -> {
@@ -40,6 +42,18 @@ fun testOnlineAsr(type: String) {
             debug = false,
         )
       }
+      "ctc-hlg" -> {
+        waveFilename = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/test_wavs/1.wav"
+        ctcFstDecoderConfig.graph = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/HLG.fst"
+        OnlineModelConfig(
+            zipformer2Ctc = OnlineZipformer2CtcModelConfig(
+                model = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/ctc-epoch-30-avg-3-chunk-16-left-128.int8.onnx",
+            ),
+            tokens = "./sherpa-onnx-streaming-zipformer-ctc-small-2024-03-18/tokens.txt",
+            numThreads = 1,
+            debug = false,
+        )
+      }
       else -> throw IllegalArgumentException(type)
     }
 
@@ -51,6 +65,7 @@ fun testOnlineAsr(type: String) {
         modelConfig = modelConfig,
         lmConfig = lmConfig,
         featConfig = featConfig,
+        ctcFstDecoderConfig=ctcFstDecoderConfig,
         endpointConfig = endpointConfig,
         enableEndpoint = true,
         decodingMethod = "greedy_search",

sherpa-onnx/java-api/Makefile

@@ -14,6 +14,7 @@ java_files += OnlineParaformerModelConfig.java
 java_files += OnlineZipformer2CtcModelConfig.java
 java_files += OnlineTransducerModelConfig.java
 java_files += OnlineModelConfig.java
+java_files += OnlineCtcFstDecoderConfig.java
 java_files += OnlineStream.java
 java_files += OnlineRecognizerConfig.java
 java_files += OnlineRecognizerResult.java
@@ -22,6 +23,7 @@ java_files += OnlineRecognizer.java
 java_files += OfflineTransducerModelConfig.java
 java_files += OfflineParaformerModelConfig.java
 java_files += OfflineWhisperModelConfig.java
+java_files += OfflineNemoEncDecCtcModelConfig.java
 java_files += OfflineModelConfig.java
 java_files += OfflineRecognizerConfig.java
 java_files += OfflineRecognizerResult.java
@@ -42,10 +44,12 @@ $(info -- class files $(class_files))
 all: $(out_jar)
 
 $(out_jar): $(class_files)
-	jar --create --verbose --file $(out_jar) -C $(out_dir) .
+	# jar --create --verbose --file $(out_jar) -C $(out_dir) ./
+	jar cvf $(out_jar) -C $(out_dir) ./
 
 clean:
 	$(RM) -rfv $(out_dir)
 
 $(class_files): $(out_dir)/$(package_dir)/%.class: src/$(package_dir)/%.java
-	javac -d $(out_dir) --class-path $(out_dir) $<
+	mkdir -p build
+	javac -d $(out_dir) -cp $(out_dir) $<

sherpa-onnx/java-api/src/com/k2fsa/sherpa/onnx/OfflineModelConfig.java

@@ -5,6 +5,7 @@ public class OfflineModelConfig {
     private final OfflineTransducerModelConfig transducer;
     private final OfflineParaformerModelConfig paraformer;
     private final OfflineWhisperModelConfig whisper;
+    private final OfflineNemoEncDecCtcModelConfig nemo;
     private final String tokens;
     private final int numThreads;
     private final boolean debug;
@@ -16,6 +17,7 @@ public class OfflineModelConfig {
         this.transducer = builder.transducer;
         this.paraformer = builder.paraformer;
         this.whisper = builder.whisper;
+        this.nemo = builder.nemo;
         this.tokens = builder.tokens;
         this.numThreads = builder.numThreads;
         this.debug = builder.debug;
@@ -64,6 +66,7 @@ public class OfflineModelConfig {
         private OfflineParaformerModelConfig paraformer = OfflineParaformerModelConfig.builder().build();
         private OfflineTransducerModelConfig transducer = OfflineTransducerModelConfig.builder().build();
         private OfflineWhisperModelConfig whisper = OfflineWhisperModelConfig.builder().build();
+        private OfflineNemoEncDecCtcModelConfig nemo = OfflineNemoEncDecCtcModelConfig.builder().build();
         private String tokens = "";
         private int numThreads = 1;
         private boolean debug = true;
@@ -84,6 +87,11 @@ public class OfflineModelConfig {
             return this;
         }
 
+        public Builder setNemo(OfflineNemoEncDecCtcModelConfig nemo) {
+            this.nemo = nemo;
+            return this;
+        }
+
         public Builder setWhisper(OfflineWhisperModelConfig whisper) {
             this.whisper = whisper;
             return this;

sherpa-onnx/java-api/src/com/k2fsa/sherpa/onnx/OfflineNemoEncDecCtcModelConfig.java

@@ -0,0 +1,31 @@
+// Copyright 2024 Xiaomi Corporation
+package com.k2fsa.sherpa.onnx;
+
+public class OfflineNemoEncDecCtcModelConfig {
+    private final String model;
+
+    private OfflineNemoEncDecCtcModelConfig(Builder builder) {
+        this.model = builder.model;
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public static class Builder {
+        private String model = "";
+
+        public OfflineNemoEncDecCtcModelConfig build() {
+            return new OfflineNemoEncDecCtcModelConfig(this);
+        }
+
+        public Builder setModel(String model) {
+            this.model = model;
+            return this;
+        }
+    }
+}

sherpa-onnx/java-api/src/com/k2fsa/sherpa/onnx/OnlineCtcFstDecoderConfig.java

@@ -0,0 +1,43 @@
+// Copyright 2024 Xiaomi Corporation
+package com.k2fsa.sherpa.onnx;
+
+public class OnlineCtcFstDecoderConfig {
+    private final String graph;
+    private final int maxActive;
+
+    private OnlineCtcFstDecoderConfig(Builder builder) {
+        this.graph = builder.graph;
+        this.maxActive = builder.maxActive;
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public String getGraph() {
+        return graph;
+    }
+
+    public float getMaxActive() {
+        return maxActive;
+    }
+
+    public static class Builder {
+        private String graph = "";
+        private int maxActive = 3000;
+
+        public OnlineCtcFstDecoderConfig build() {
+            return new OnlineCtcFstDecoderConfig(this);
+        }
+
+        public Builder setGraph(String model) {
+            this.graph = graph;
+            return this;
+        }
+
+        public Builder setMaxActive(int maxActive) {
+            this.maxActive = maxActive;
+            return this;
+        }
+    }
+}

sherpa-onnx/java-api/src/com/k2fsa/sherpa/onnx/OnlineRecognizerConfig.java

@@ -6,6 +6,8 @@ public class OnlineRecognizerConfig {
     private final FeatureConfig featConfig;
     private final OnlineModelConfig modelConfig;
     private final OnlineLMConfig lmConfig;
+
+    private final OnlineCtcFstDecoderConfig ctcFstDecoderConfig;
     private final EndpointConfig endpointConfig;
     private final boolean enableEndpoint;
     private final String decodingMethod;
@@ -17,6 +19,7 @@ public class OnlineRecognizerConfig {
         this.featConfig = builder.featConfig;
         this.modelConfig = builder.modelConfig;
         this.lmConfig = builder.lmConfig;
+        this.ctcFstDecoderConfig = builder.ctcFstDecoderConfig;
         this.endpointConfig = builder.endpointConfig;
         this.enableEndpoint = builder.enableEndpoint;
         this.decodingMethod = builder.decodingMethod;
@@ -37,6 +40,7 @@ public class OnlineRecognizerConfig {
         private FeatureConfig featConfig = FeatureConfig.builder().build();
         private OnlineModelConfig modelConfig = OnlineModelConfig.builder().build();
         private OnlineLMConfig lmConfig = OnlineLMConfig.builder().build();
+        private OnlineCtcFstDecoderConfig ctcFstDecoderConfig = OnlineCtcFstDecoderConfig.builder().build();
         private EndpointConfig endpointConfig = EndpointConfig.builder().build();
         private boolean enableEndpoint = true;
         private String decodingMethod = "greedy_search";
@@ -63,6 +67,11 @@ public class OnlineRecognizerConfig {
             return this;
         }
 
+        public Builder setCtcFstDecoderConfig(OnlineCtcFstDecoderConfig ctcFstDecoderConfig) {
+            this.ctcFstDecoderConfig = ctcFstDecoderConfig;
+            return this;
+        }
+
         public Builder setEndpointConfig(EndpointConfig endpointConfig) {
             this.endpointConfig = endpointConfig;
             return this;

sherpa-onnx/jni/offline-recognizer.cc

@@ -147,6 +147,19 @@ static OfflineRecognizerConfig GetOfflineConfig(JNIEnv *env, jobject config) {
   ans.model_config.whisper.tail_paddings =
       env->GetIntField(whisper_config, fid);
 
+  fid = env->GetFieldID(
+      model_config_cls, "nemo",
+      "Lcom/k2fsa/sherpa/onnx/OfflineNemoEncDecCtcModelConfig;");
+  jobject nemo_config = env->GetObjectField(model_config, fid);
+  jclass nemo_config_cls = env->GetObjectClass(nemo_config);
+
+  fid = env->GetFieldID(paraformer_config_cls, "model", "Ljava/lang/String;");
+
+  s = (jstring)env->GetObjectField(nemo_config, fid);
+  p = env->GetStringUTFChars(s, nullptr);
+  ans.model_config.nemo_ctc.model = p;
+  env->ReleaseStringUTFChars(s, p);
+
   return ans;
 }
 

sherpa-onnx/jni/online-recognizer.cc

@@ -198,6 +198,22 @@ static OnlineRecognizerConfig GetConfig(JNIEnv *env, jobject config) {
   fid = env->GetFieldID(lm_model_config_cls, "scale", "F");
   ans.lm_config.scale = env->GetFloatField(lm_model_config, fid);
 
+  fid = env->GetFieldID(cls, "ctcFstDecoderConfig",
+                        "Lcom/k2fsa/sherpa/onnx/OnlineCtcFstDecoderConfig;");
+
+  jobject fst_decoder_config = env->GetObjectField(config, fid);
+  jclass fst_decoder_config_cls = env->GetObjectClass(fst_decoder_config);
+
+  fid = env->GetFieldID(fst_decoder_config_cls, "graph", "Ljava/lang/String;");
+  s = (jstring)env->GetObjectField(fst_decoder_config, fid);
+  p = env->GetStringUTFChars(s, nullptr);
+  ans.ctc_fst_decoder_config.graph = p;
+  env->ReleaseStringUTFChars(s, p);
+
+  fid = env->GetFieldID(fst_decoder_config_cls, "maxActive", "I");
+  ans.ctc_fst_decoder_config.max_active =
+      env->GetIntField(fst_decoder_config, fid);
+
   return ans;
 }
 }  // namespace sherpa_onnx

sherpa-onnx/jni/wave-reader.cc

@@ -6,6 +6,7 @@
 #include <fstream>
 
 #include "sherpa-onnx/csrc/macros.h"
+#include "sherpa-onnx/csrc/onnx-utils.h"
 #include "sherpa-onnx/jni/common.h"
 
 static jobjectArray ReadWaveImpl(JNIEnv *env, std::istream &is,

sherpa-onnx/kotlin-api/OfflineRecognizer.kt

@@ -18,6 +18,10 @@ data class OfflineParaformerModelConfig(
     var model: String = "",
 )
 
+data class OfflineNemoEncDecCtcModelConfig(
+    var model: String = "",
+)
+
 data class OfflineWhisperModelConfig(
     var encoder: String = "",
     var decoder: String = "",
@@ -30,6 +34,7 @@ data class OfflineModelConfig(
     var transducer: OfflineTransducerModelConfig = OfflineTransducerModelConfig(),
     var paraformer: OfflineParaformerModelConfig = OfflineParaformerModelConfig(),
     var whisper: OfflineWhisperModelConfig = OfflineWhisperModelConfig(),
+    var nemo: OfflineNemoEncDecCtcModelConfig = OfflineNemoEncDecCtcModelConfig(),
     var numThreads: Int = 1,
     var debug: Boolean = false,
     var provider: String = "cpu",
@@ -216,6 +221,16 @@ fun getOfflineModelConfig(type: Int): OfflineModelConfig? {
             )
         }
 
+        6 -> {
+            val modelDir = "sherpa-onnx-nemo-ctc-en-citrinet-512"
+            return OfflineModelConfig(
+                nemo = OfflineNemoEncDecCtcModelConfig(
+                    model = "$modelDir/model.int8.onnx",
+                ),
+                tokens = "$modelDir/tokens.txt",
+            )
+        }
+
     }
     return null
 }

sherpa-onnx/kotlin-api/OnlineRecognizer.kt

@@ -45,11 +45,17 @@ data class OnlineLMConfig(
     var scale: Float = 0.5f,
 )
 
+data class OnlineCtcFstDecoderConfig(
+    var graph: String = "",
+    var maxActive: Int = 3000,
+)
+
 
 data class OnlineRecognizerConfig(
     var featConfig: FeatureConfig = FeatureConfig(),
     var modelConfig: OnlineModelConfig,
     var lmConfig: OnlineLMConfig = OnlineLMConfig(),
+    var ctcFstDecoderConfig : OnlineCtcFstDecoderConfig = OnlineCtcFstDecoderConfig(),
     var endpointConfig: EndpointConfig = EndpointConfig(),
     var enableEndpoint: Boolean = true,
     var decodingMethod: String = "greedy_search",