Add KWS examples for Java API (#930)

@@ -107,6 +107,13 @@ jobs:
             make -j4
             ls -lh lib
 
+      - name:  Run java test (kws)
+        shell: bash
+        run: |
+          cd ./java-api-examples
+          ./run-kws-from-file.sh
+          rm -rf sherpa-onnx-*
+
       - name:  Run java test (VAD + Non-streaming Paraformer)
         shell: bash
         run: |

+// Copyright 2024 Xiaomi Corporation
+
+// This file shows how to use a keyword spotter model to spot keywords from
+// a file.
+
+import com.k2fsa.sherpa.onnx.*;
+
+public class KyewordSpotterFromFile {
+  public static void main(String[] args) {
+    // please download test files from https://github.com/k2-fsa/sherpa-onnx/releases/tag/kws-models
+    String encoder =
+        "./sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/encoder-epoch-12-avg-2-chunk-16-left-64.onnx";
+    String decoder =
+        "./sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/decoder-epoch-12-avg-2-chunk-16-left-64.onnx";
+    String joiner =
+        "./sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/joiner-epoch-12-avg-2-chunk-16-left-64.onnx";
+    String tokens = "./sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/tokens.txt";
+
+    String keywordsFile =
+        "./sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/test_wavs/test_keywords.txt";
+
+    String waveFilename = "./sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/test_wavs/3.wav";
+
+    OnlineTransducerModelConfig transducer =
+        OnlineTransducerModelConfig.builder()
+            .setEncoder(encoder)
+            .setDecoder(decoder)
+            .setJoiner(joiner)
+            .build();
+
+    OnlineModelConfig modelConfig =
+        OnlineModelConfig.builder()
+            .setTransducer(transducer)
+            .setTokens(tokens)
+            .setNumThreads(1)
+            .setDebug(true)
+            .build();
+
+    KeywordSpotterConfig config =
+        KeywordSpotterConfig.builder()
+            .setOnlineModelConfig(modelConfig)
+            .setKeywordsFile(keywordsFile)
+            .build();
+
+    KeywordSpotter kws = new KeywordSpotter(config);
+    OnlineStream stream = kws.createStream();
+
+    WaveReader reader = new WaveReader(waveFilename);
+
+    stream.acceptWaveform(reader.getSamples(), reader.getSampleRate());
+
+    float[] tailPaddings = new float[(int) (0.8 * reader.getSampleRate())];
+    stream.acceptWaveform(tailPaddings, reader.getSampleRate());
+    while (kws.isReady(stream)) {
+      kws.decode(stream);
+
+      String keyword = kws.getResult(stream).getKeyword();
+      if (!keyword.isEmpty()) {
+        System.out.printf("Detected keyword: %s\n", keyword);
+      }
+    }
+
+    kws.release();
+  }
+}

@@ -68,3 +68,9 @@ The punctuation model supports both English and Chinese.
 ```bash
 ./run-vad-non-streaming-paraformer.sh
 ```
+
+## Keyword spotter
+
+```bash
+./run-kws-from-file.sh
+```

@@ -91,6 +91,7 @@ public class VadNonStreamingParaformer {
           stream.acceptWaveform(segment.getSamples(), 16000);
           recognizer.decode(stream);
           String text = recognizer.getResult(stream).getText();
+          stream.release();
 
           if (!text.isEmpty()) {
             System.out.printf("%.3f--%.3f: %s\n", startTime, startTime + duration, text);
@@ -100,5 +101,8 @@ public class VadNonStreamingParaformer {
         }
       }
     }
+
+    vad.release();
+    recognizer.release();
   }
 }

@@ -75,5 +75,7 @@ public class VadRemoveSilence {
     String outFilename = "lei-jun-test-no-silence.wav";
     WaveWriter.write(outFilename, allSamples, 16000);
     System.out.printf("Saved to %s\n", outFilename);
+
+    vad.release();
   }
 }

+#!/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-kws-zipformer-wenetspeech-3.3M-2024-01-01/tokens.txt ]; then
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/kws-models/sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01.tar.bz2
+  tar xvf sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01.tar.bz2
+  rm sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01.tar.bz2
+fi
+
+java \
+  -Djava.library.path=$PWD/../build/lib \
+  -cp ../sherpa-onnx/java-api/build/sherpa-onnx.jar \
+  ./KeywordSpotterFromFile.java

@@ -62,6 +62,10 @@ java_files += VadModelConfig.java
 java_files += SpeechSegment.java
 java_files += Vad.java
 
+java_files += KeywordSpotterConfig.java
+java_files += KeywordSpotterResult.java
+java_files += KeywordSpotter.java
+
 class_files := $(java_files:%.java=%.class)
 
 java_files := $(addprefix src/$(package_dir)/,$(java_files))

+// Copyright 2024 Xiaomi Corporation
+
+package com.k2fsa.sherpa.onnx;
+
+public class KeywordSpotter {
+    static {
+        System.loadLibrary("sherpa-onnx-jni");
+    }
+
+    private long ptr = 0;
+
+    public KeywordSpotter(KeywordSpotterConfig config) {
+        ptr = newFromFile(config);
+    }
+
+    public OnlineStream createStream(String keywords) {
+        long p = createStream(ptr, keywords);
+        return new OnlineStream(p);
+    }
+
+    public OnlineStream createStream() {
+        long p = createStream(ptr, "");
+        return new OnlineStream(p);
+    }
+
+    public void decode(OnlineStream s) {
+        decode(ptr, s.getPtr());
+    }
+
+    public boolean isReady(OnlineStream s) {
+        return isReady(ptr, s.getPtr());
+    }
+
+    public KeywordSpotterResult getResult(OnlineStream s) {
+        Object[] arr = getResult(ptr, s.getPtr());
+        String keyword = (String) arr[0];
+        String[] tokens = (String[]) arr[1];
+        float[] timestamps = (float[]) arr[2];
+        return new KeywordSpotterResult(keyword, tokens, timestamps);
+    }
+
+    protected void finalize() throws Throwable {
+        release();
+    }
+
+    // You'd better call it manually if it is not used anymore
+    public void release() {
+        if (this.ptr == 0) {
+            return;
+        }
+        delete(this.ptr);
+        this.ptr = 0;
+    }
+
+    private native long newFromFile(KeywordSpotterConfig config);
+
+    private native void delete(long ptr);
+
+    private native long createStream(long ptr, String keywords);
+
+    private native void decode(long ptr, long streamPtr);
+
+    private native boolean isReady(long ptr, long streamPtr);
+
+    private native Object[] getResult(long ptr, long streamPtr);
+}

+// Copyright 2024 Xiaomi Corporation
+
+package com.k2fsa.sherpa.onnx;
+
+public class KeywordSpotterConfig {
+    private final FeatureConfig featConfig;
+    private final OnlineModelConfig modelConfig;
+
+    private final int maxActivePaths;
+    private final String keywordsFile;
+    private final float keywordsScore;
+    private final float keywordsThreshold;
+    private final int numTrailingBlanks;
+
+    private KeywordSpotterConfig(Builder builder) {
+        this.featConfig = builder.featConfig;
+        this.modelConfig = builder.modelConfig;
+        this.maxActivePaths = builder.maxActivePaths;
+        this.keywordsFile = builder.keywordsFile;
+        this.keywordsScore = builder.keywordsScore;
+        this.keywordsThreshold = builder.keywordsThreshold;
+        this.numTrailingBlanks = builder.numTrailingBlanks;
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+        private FeatureConfig featConfig = FeatureConfig.builder().build();
+        private OnlineModelConfig modelConfig = OnlineModelConfig.builder().build();
+        private int maxActivePaths = 4;
+        private String keywordsFile = "keywords.txt";
+        private float keywordsScore = 1.5f;
+        private float keywordsThreshold = 0.25f;
+        private int numTrailingBlanks = 2;
+
+        public KeywordSpotterConfig build() {
+            return new KeywordSpotterConfig(this);
+        }
+
+        public Builder setFeatureConfig(FeatureConfig featConfig) {
+            this.featConfig = featConfig;
+            return this;
+        }
+
+        public Builder setOnlineModelConfig(OnlineModelConfig modelConfig) {
+            this.modelConfig = modelConfig;
+            return this;
+        }
+
+        public Builder setMaxActivePaths(int maxActivePaths) {
+            this.maxActivePaths = maxActivePaths;
+            return this;
+        }
+
+        public Builder setKeywordsFile(String keywordsFile) {
+            this.keywordsFile = keywordsFile;
+            return this;
+        }
+
+        public Builder setKeywordsScore(float keywordsScore) {
+            this.keywordsScore = keywordsScore;
+            return this;
+        }
+
+        public Builder setKeywordsThreshold(float keywordsThreshold) {
+            this.keywordsThreshold = keywordsThreshold;
+            return this;
+        }
+
+        public Builder setNumTrailingBlanks(int numTrailingBlanks) {
+            this.numTrailingBlanks = numTrailingBlanks;
+            return this;
+        }
+    }
+}

+// Copyright 2024 Xiaomi Corporation
+
+package com.k2fsa.sherpa.onnx;
+
+public class KeywordSpotterResult {
+    private final String keyword;
+    private final String[] tokens;
+    private final float[] timestamps;
+
+    public KeywordSpotterResult(String keyword, String[] tokens, float[] timestamps) {
+        this.keyword = keyword;
+        this.tokens = tokens;
+        this.timestamps = timestamps;
+    }
+
+    public String getKeyword() {
+        return keyword;
+    }
+
+    public String[] getTokens() {
+        return tokens;
+    }
+
+    public float[] getTimestamps() {
+        return timestamps;
+    }
+}

@@ -10,7 +10,6 @@ public class OnlineRecognizer {
 
     private long ptr = 0;
 
-
     public OnlineRecognizer(OnlineRecognizerConfig config) {
         ptr = newFromFile(config);
     }
@@ -19,7 +18,6 @@ public class OnlineRecognizer {
         decode(ptr, s.getPtr());
     }
 
-
     public boolean isReady(OnlineStream s) {
         return isReady(ptr, s.getPtr());
     }