Add Android APK for Silero VAD (#335)

.github/workflows/apk.yaml

@@ -38,6 +38,7 @@ jobs:
         shell: bash
         run: |
           export ANDROID_NDK=$ANDROID_NDK_LATEST_HOME
+          ./build-apk-vad.sh
           ./build-apk-two-pass.sh
           ./build-apk.sh
 

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
 project(sherpa-onnx)
 
-set(SHERPA_ONNX_VERSION "1.7.18")
+set(SHERPA_ONNX_VERSION "1.7.19")
 
 # Disable warning about
 #

android/README.md

@@ -0,0 +1,5 @@
+# Introduction
+
+Please refer to
+https://k2-fsa.github.io/sherpa/onnx/android/index.html
+for usage.

android/SherpaOnnx/app/src/main/java/com/k2fsa/sherpa/onnx/SherpaOnnx.kt

@@ -1,3 +1,4 @@
+// Copyright (c)  2023  Xiaomi Corporation
 package com.k2fsa.sherpa.onnx
 
 import android.content.res.AssetManager

android/SherpaOnnx/app/src/main/java/com/k2fsa/sherpa/onnx/WaveReader.kt

@@ -1,3 +1,4 @@
+// Copyright (c)  2023  Xiaomi Corporation
 package com.k2fsa.sherpa.onnx
 
 import android.content.res.AssetManager

android/SherpaOnnxVad/.gitignore

@@ -0,0 +1,15 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
+local.properties

android/SherpaOnnxVad/.idea/.gitignore

@@ -0,0 +1,3 @@
+# Default ignored files
+/shelf/
+/workspace.xml

android/SherpaOnnxVad/.idea/compiler.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <bytecodeTargetLevel target="11" />
+  </component>
+</project>

android/SherpaOnnxVad/.idea/gradle.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
+  <component name="GradleSettings">
+    <option name="linkedExternalProjectsSettings">
+      <GradleProjectSettings>
+        <option name="testRunner" value="GRADLE" />
+        <option name="distributionType" value="DEFAULT_WRAPPED" />
+        <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="modules">
+          <set>
+            <option value="$PROJECT_DIR$" />
+            <option value="$PROJECT_DIR$/app" />
+          </set>
+        </option>
+      </GradleProjectSettings>
+    </option>
+  </component>
+</project>

android/SherpaOnnxVad/.idea/misc.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="Android Studio default JDK" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/build/classes" />
+  </component>
+  <component name="ProjectType">
+    <option name="id" value="Android" />
+  </component>
+</project>

android/SherpaOnnxVad/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/../.." vcs="Git" />
+  </component>
+</project>

android/SherpaOnnxVad/app/.gitignore

@@ -0,0 +1 @@
+/build

android/SherpaOnnxVad/app/build.gradle

@@ -0,0 +1,44 @@
+plugins {
+    id 'com.android.application'
+    id 'org.jetbrains.kotlin.android'
+}
+
+android {
+    namespace 'com.k2fsa.sherpa.onnx'
+    compileSdk 33
+
+    defaultConfig {
+        applicationId "com.k2fsa.sherpa.onnx"
+        minSdk 21
+        targetSdk 33
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
+}
+
+dependencies {
+
+    implementation 'androidx.core:core-ktx:1.7.0'
+    implementation 'androidx.appcompat:appcompat:1.6.1'
+    implementation 'com.google.android.material:material:1.9.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+}

android/SherpaOnnxVad/app/proguard-rules.pro

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

android/SherpaOnnxVad/app/src/androidTest/java/com/k2fsa/sherpa/onnx/ExampleInstrumentedTest.kt

@@ -0,0 +1,24 @@
+package com.k2fsa.sherpa.onnx
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.k2fsa.sherpa.onnx", appContext.packageName)
+    }
+}

android/SherpaOnnxVad/app/src/main/AndroidManifest.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
+
+    <application
+        android:allowBackup="true"
+        android:dataExtractionRules="@xml/data_extraction_rules"
+        android:fullBackupContent="@xml/backup_rules"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.SherpaOnnxVad"
+        tools:targetApi="31">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+
+            <meta-data
+                android:name="android.app.lib_name"
+                android:value="" />
+        </activity>
+    </application>
+
+</manifest>

android/SherpaOnnxVad/app/src/main/assets/.gitignore

@@ -0,0 +1 @@
+*.onnx

android/SherpaOnnxVad/app/src/main/java/com/k2fsa/sherpa/onnx/MainActivity.kt

@@ -0,0 +1,174 @@
+package com.k2fsa.sherpa.onnx
+
+import android.Manifest
+import android.content.pm.PackageManager
+import android.media.AudioFormat
+import android.media.AudioRecord
+import android.media.MediaRecorder
+import android.os.Bundle
+import android.util.Log
+import android.view.View
+import android.widget.Button
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.app.ActivityCompat
+import kotlin.concurrent.thread
+
+
+private const val TAG = "sherpa-onnx"
+private const val REQUEST_RECORD_AUDIO_PERMISSION = 200
+
+class MainActivity : AppCompatActivity() {
+
+    private lateinit var recordButton: Button
+    private lateinit var circle: View
+
+    private lateinit var vad: Vad
+
+    private var audioRecord: AudioRecord? = null
+    private var recordingThread: Thread? = null
+    private val audioSource = MediaRecorder.AudioSource.MIC
+    private val sampleRateInHz = 16000
+    private val channelConfig = AudioFormat.CHANNEL_IN_MONO
+
+    // Note: We don't use AudioFormat.ENCODING_PCM_FLOAT
+    // since the AudioRecord.read(float[]) needs API level >= 23
+    // but we are targeting API level >= 21
+    private val audioFormat = AudioFormat.ENCODING_PCM_16BIT
+
+    private val permissions: Array<String> = arrayOf(Manifest.permission.RECORD_AUDIO)
+
+    @Volatile
+    private var isRecording: Boolean = false
+
+    override fun onRequestPermissionsResult(
+        requestCode: Int, permissions: Array<String>, grantResults: IntArray
+    ) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
+        val permissionToRecordAccepted = if (requestCode == REQUEST_RECORD_AUDIO_PERMISSION) {
+            grantResults[0] == PackageManager.PERMISSION_GRANTED
+        } else {
+            false
+        }
+
+        if (!permissionToRecordAccepted) {
+            Log.e(TAG, "Audio record is disallowed")
+            finish()
+        }
+
+        Log.i(TAG, "Audio record is permitted")
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
+
+        ActivityCompat.requestPermissions(this, permissions, REQUEST_RECORD_AUDIO_PERMISSION)
+
+        Log.i(TAG, "Start to initialize model")
+        initVadModel()
+        Log.i(TAG, "Finished initializing model")
+
+        circle= findViewById(R.id.powerCircle)
+
+        recordButton = findViewById(R.id.record_button)
+        recordButton.setOnClickListener { onclick() }
+    }
+
+    private fun onclick() {
+        if (!isRecording) {
+            val ret = initMicrophone()
+            if (!ret) {
+                Log.e(TAG, "Failed to initialize microphone")
+                return
+            }
+            Log.i(TAG, "state: ${audioRecord?.state}")
+            audioRecord!!.startRecording()
+            recordButton.setText(R.string.stop)
+            isRecording = true
+
+            vad.reset()
+            recordingThread = thread(true) {
+                processSamples()
+            }
+            Log.i(TAG, "Started recording")
+            onVad(false)
+
+        } else {
+            isRecording = false
+
+            audioRecord!!.stop()
+            audioRecord!!.release()
+            audioRecord = null
+
+            recordButton.setText(R.string.start)
+            onVad(false)
+            Log.i(TAG, "Stopped recording")
+        }
+    }
+
+    private fun onVad(isSpeech: Boolean) {
+        if(isSpeech) {
+            circle.background = resources.getDrawable(R.drawable.red_circle)
+        } else {
+            circle.background = resources.getDrawable(R.drawable.black_circle)
+        }
+    }
+
+    private  fun initVadModel() {
+        val type = 0
+        println("Select VAD model type ${type}")
+        val config = getVadModelConfig(type)
+
+        vad = Vad(
+            assetManager = application.assets,
+            config = config!!,
+        )
+    }
+
+    private fun initMicrophone(): Boolean {
+        if (ActivityCompat.checkSelfPermission(
+                this, Manifest.permission.RECORD_AUDIO
+            ) != PackageManager.PERMISSION_GRANTED
+        ) {
+            ActivityCompat.requestPermissions(this, permissions, REQUEST_RECORD_AUDIO_PERMISSION)
+            return false
+        }
+
+        val numBytes = AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, audioFormat)
+        Log.i(
+            TAG, "buffer size in milliseconds: ${numBytes * 1000.0f / sampleRateInHz}"
+        )
+
+        audioRecord = AudioRecord(
+            audioSource,
+            sampleRateInHz,
+            channelConfig,
+            audioFormat,
+            numBytes * 2 // a sample has two bytes as we are using 16-bit PCM
+        )
+        return true
+    }
+
+    private fun processSamples() {
+        Log.i(TAG, "processing samples")
+
+        val bufferSize = 512 // in samples
+        val buffer = ShortArray(bufferSize)
+
+        while (isRecording) {
+            val ret = audioRecord?.read(buffer, 0, buffer.size)
+            if (ret != null && ret > 0) {
+                val samples = FloatArray(ret) { buffer[it] / 32768.0f }
+
+                vad.acceptWaveform(samples)
+                while(!vad.empty()) {vad.pop();}
+
+                val isSpeechDetected = vad.isSpeechDetected()
+
+                runOnUiThread {
+                    onVad(isSpeechDetected)
+                }
+            }
+        }
+    }
+}

android/SherpaOnnxVad/app/src/main/java/com/k2fsa/sherpa/onnx/Vad.kt

@@ -0,0 +1,101 @@
+// Copyright (c)  2023  Xiaomi Corporation
+package com.k2fsa.sherpa.onnx
+
+import android.content.res.AssetManager
+
+data class SileroVadModelConfig(
+    var model: String,
+    var threshold: Float = 0.5F,
+    var minSilenceDuration: Float = 0.25F,
+    var minSpeechDuration: Float = 0.25F,
+    var windowSize: Int = 512,
+)
+
+data class VadModelConfig(
+    var sileroVadModelConfig: SileroVadModelConfig,
+    var sampleRate: Int = 16000,
+    var numThreads: Int = 1,
+    var provider: String = "cpu",
+    var debug: Boolean = false,
+)
+
+class Vad(
+    assetManager: AssetManager? = null,
+    var config: VadModelConfig,
+) {
+    private val ptr: Long
+
+    init {
+        if (assetManager != null) {
+            ptr = new(assetManager, config)
+        } else {
+            ptr = newFromFile(config)
+        }
+    }
+
+    protected fun finalize() {
+        delete(ptr)
+    }
+
+    fun acceptWaveform(samples: FloatArray) = acceptWaveform(ptr, samples)
+
+    fun empty(): Boolean = empty(ptr)
+    fun pop() = pop(ptr)
+
+    // return an array containing
+    // [start: Int, samples: FloatArray]
+    fun front() = front(ptr)
+
+    fun isSpeechDetected(): Boolean = isSpeechDetected(ptr)
+
+    fun reset() = reset(ptr)
+
+    private external fun delete(ptr: Long)
+
+    private external fun new(
+        assetManager: AssetManager,
+        config: VadModelConfig,
+    ): Long
+
+    private external fun newFromFile(
+        config: VadModelConfig,
+    ): Long
+
+    private external fun acceptWaveform(ptr: Long, samples: FloatArray)
+    private external fun empty(ptr: Long): Boolean
+    private external fun pop(ptr: Long)
+    private external fun front(ptr: Long): Array<Any>
+    private external fun isSpeechDetected(ptr: Long): Boolean
+    private external fun reset(ptr: Long)
+
+    companion object {
+        init {
+            System.loadLibrary("sherpa-onnx-jni")
+        }
+    }
+}
+
+// Please visit
+// https://github.com/snakers4/silero-vad/blob/master/files/silero_vad.onnx
+// to download silero_vad.onnx
+// and put it inside the assets/
+// directory
+fun getVadModelConfig(type: Int): VadModelConfig? {
+    when (type) {
+        0 -> {
+            return VadModelConfig(
+                sileroVadModelConfig = SileroVadModelConfig(
+                    model = "silero_vad.onnx",
+                    threshold = 0.5F,
+                    minSilenceDuration = 0.25F,
+                    minSpeechDuration = 0.25F,
+                    windowSize = 512,
+                ),
+                sampleRate = 16000,
+                numThreads = 1,
+                provider = "cpu",
+            )
+        }
+    }
+    return null;
+}

android/SherpaOnnxVad/app/src/main/jniLibs/.gitignore

@@ -0,0 +1 @@
+*.so

android/SherpaOnnxVad/app/src/main/res/drawable-v24/ic_launcher_foreground.xml

@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="85.84757"
+                android:endY="92.4963"
+                android:startX="42.9492"
+                android:startY="49.59793"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>

android/SherpaOnnxVad/app/src/main/res/drawable/black_circle.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+  <item>
+    <shape  android:shape="oval">
+
+    <solid  android:color="#FF000000"/>
+
+    <size
+        android:width="300dp"
+        android:height="300dp"/>
+    </shape>
+  </item>
+</selector>

android/SherpaOnnxVad/app/src/main/res/drawable/ic_launcher_background.xml

@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#3DDC84"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+</vector>

android/SherpaOnnxVad/app/src/main/res/drawable/red_circle.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+  <item>
+    <shape  android:shape="oval">
+
+    <solid  android:color="#FFFF0000"/>
+
+    <size
+        android:width="300dp"
+        android:height="300dp"/>
+    </shape>
+  </item>
+</selector>

android/SherpaOnnxVad/app/src/main/res/layout/activity_main.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".MainActivity">
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="bottom"
+        android:orientation="vertical"
+        >
+
+        <Space
+            android:layout_width="match_parent"
+            android:layout_height="10dp" />
+
+        <LinearLayout
+            android:id="@+id/powerCircle"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:background="@drawable/black_circle"
+            android:orientation="vertical" />
+
+        <Space
+            android:layout_width="match_parent"
+            android:layout_height="200dp" />
+
+        <Button
+            android:id="@+id/record_button"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/start" />
+
+
+
+    </LinearLayout>
+
+
+
+</androidx.constraintlayout.widget.ConstraintLayout>

android/SherpaOnnxVad/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

android/SherpaOnnxVad/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

android/SherpaOnnxVad/app/src/main/res/values-night/themes.xml

@@ -0,0 +1,16 @@
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <!-- Base application theme. -->
+    <style name="Theme.SherpaOnnxVad" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <!-- Primary brand color. -->
+        <item name="colorPrimary">@color/purple_200</item>
+        <item name="colorPrimaryVariant">@color/purple_700</item>
+        <item name="colorOnPrimary">@color/black</item>
+        <!-- Secondary brand color. -->
+        <item name="colorSecondary">@color/teal_200</item>
+        <item name="colorSecondaryVariant">@color/teal_200</item>
+        <item name="colorOnSecondary">@color/black</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
+        <!-- Customize your theme here. -->
+    </style>
+</resources>

android/SherpaOnnxVad/app/src/main/res/values/colors.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="purple_200">#FFBB86FC</color>
+    <color name="purple_500">#FF6200EE</color>
+    <color name="purple_700">#FF3700B3</color>
+    <color name="teal_200">#FF03DAC5</color>
+    <color name="teal_700">#FF018786</color>
+    <color name="black">#FF000000</color>
+    <color name="white">#FFFFFFFF</color>
+</resources>

android/SherpaOnnxVad/app/src/main/res/values/strings.xml

@@ -0,0 +1,7 @@
+<resources>
+    <string name="app_name">Next-gen Kaldi: SileroVAD</string>
+
+    <string name="hint">Click the Start button to play Silero VAD with Next-gen Kaldi.</string>
+    <string name="start">Start</string>
+    <string name="stop">Stop</string>
+</resources>

android/SherpaOnnxVad/app/src/main/res/values/themes.xml

@@ -0,0 +1,16 @@
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <!-- Base application theme. -->
+    <style name="Theme.SherpaOnnxVad" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <!-- Primary brand color. -->
+        <item name="colorPrimary">@color/purple_500</item>
+        <item name="colorPrimaryVariant">@color/purple_700</item>
+        <item name="colorOnPrimary">@color/white</item>
+        <!-- Secondary brand color. -->
+        <item name="colorSecondary">@color/teal_200</item>
+        <item name="colorSecondaryVariant">@color/teal_700</item>
+        <item name="colorOnSecondary">@color/black</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
+        <!-- Customize your theme here. -->
+    </style>
+</resources>

android/SherpaOnnxVad/app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+   Sample backup rules file; uncomment and customize as necessary.
+   See https://developer.android.com/guide/topics/data/autobackup
+   for details.
+   Note: This file is ignored for devices older that API 31
+   See https://developer.android.com/about/versions/12/backup-restore
+-->
+<full-backup-content>
+    <!--
+   <include domain="sharedpref" path="."/>
+   <exclude domain="sharedpref" path="device.xml"/>
+-->
+</full-backup-content>

android/SherpaOnnxVad/app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+   Sample data extraction rules file; uncomment and customize as necessary.
+   See https://developer.android.com/about/versions/12/backup-restore#xml-changes
+   for details.
+-->
+<data-extraction-rules>
+    <cloud-backup>
+        <!-- TODO: Use <include> and <exclude> to control what is backed up.
+        <include .../>
+        <exclude .../>
+        -->
+    </cloud-backup>
+    <!--
+    <device-transfer>
+        <include .../>
+        <exclude .../>
+    </device-transfer>
+    -->
+</data-extraction-rules>

android/SherpaOnnxVad/app/src/test/java/com/k2fsa/sherpa/onnx/ExampleUnitTest.kt

@@ -0,0 +1,17 @@
+package com.k2fsa.sherpa.onnx
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}

android/SherpaOnnxVad/build.gradle

@@ -0,0 +1,6 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+plugins {
+    id 'com.android.application' version '7.3.1' apply false
+    id 'com.android.library' version '7.3.1' apply false
+    id 'org.jetbrains.kotlin.android' version '1.7.20' apply false
+}

android/SherpaOnnxVad/gradle.properties

@@ -0,0 +1,23 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Kotlin code style for this project: "official" or "obsolete":
+kotlin.code.style=official
+# Enables namespacing of each library's R class so that its R class includes only the
+# resources declared in the library itself and none from the library's dependencies,
+# thereby reducing the size of the R class for that library
+android.nonTransitiveRClass=true

android/SherpaOnnxVad/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Sat Sep 23 10:24:21 CST 2023
+distributionBase=GRADLE_USER_HOME
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
+distributionPath=wrapper/dists
+zipStorePath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME

android/SherpaOnnxVad/gradlew

@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"

android/SherpaOnnxVad/gradlew.bat

@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

android/SherpaOnnxVad/settings.gradle

@@ -0,0 +1,16 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        google()
+        mavenCentral()
+    }
+}
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+rootProject.name = "SherpaOnnxVad"
+include ':app'

build-android-arm64-v8a.sh

@@ -45,7 +45,9 @@ sleep 1
 onnxruntime_version=v1.16.0
 
 if [ ! -f ./android-onnxruntime-libs/$onnxruntime_version/jni/arm64-v8a/libonnxruntime.so ]; then
-  GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  if [ ! -d android-onnxruntime-libs ]; then
+    GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  fi
   pushd android-onnxruntime-libs
   git lfs pull --include "$onnxruntime_version/jni/arm64-v8a/libonnxruntime.so"
   ln -s $onnxruntime_version/jni .

build-android-armv7-eabi.sh

@@ -46,7 +46,9 @@ sleep 1
 onnxruntime_version=v1.16.0
 
 if [ ! -f ./android-onnxruntime-libs/$onnxruntime_version/jni/armeabi-v7a/libonnxruntime.so ]; then
-  GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  if [ ! -d android-onnxruntime-libs ]; then
+    GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  fi
   pushd android-onnxruntime-libs
   git lfs pull --include "$onnxruntime_version/jni/armeabi-v7a/libonnxruntime.so"
   ln -s $onnxruntime_version/jni .

build-android-x86-64.sh

@@ -46,7 +46,9 @@ sleep 1
 onnxruntime_version=v1.16.0
 
 if [ ! -f ./android-onnxruntime-libs/$onnxruntime_version/jni/x86_64/libonnxruntime.so ]; then
-  GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  if [ ! -d android-onnxruntime-libs ]; then
+    GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  fi
   pushd android-onnxruntime-libs
   git lfs pull --include "$onnxruntime_version/jni/x86_64/libonnxruntime.so"
   ln -s $onnxruntime_version/jni .

build-android-x86.sh

@@ -46,7 +46,9 @@ sleep 1
 onnxruntime_version=v1.16.0
 
 if [ ! -f ./android-onnxruntime-libs/$onnxruntime_version/jni/x86/libonnxruntime.so ]; then
-  GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  if [ ! -d android-onnxruntime-libs ]; then
+    GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/android-onnxruntime-libs
+  fi
   pushd android-onnxruntime-libs
   git lfs pull --include "$onnxruntime_version/jni/x86/libonnxruntime.so"
   ln -s $onnxruntime_version/jni .

build-apk-vad.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+
+# Please set the environment variable ANDROID_NDK
+# before running this script
+
+# Inside the $ANDROID_NDK directory, you can find a binary ndk-build
+# and some other files like the file "build/cmake/android.toolchain.cmake"
+
+set -e
+
+log() {
+  # This function is from espnet
+  local fname=${BASH_SOURCE[1]##*/}
+  echo -e "$(date '+%Y-%m-%d %H:%M:%S') (${fname}:${BASH_LINENO[0]}:${FUNCNAME[1]}) $*"
+}
+
+SHERPA_ONNX_VERSION=$(grep "SHERPA_ONNX_VERSION" ./CMakeLists.txt  | cut -d " " -f 2  | cut -d '"' -f 2)
+
+log "Building APK for sherpa-onnx v${SHERPA_ONNX_VERSION}"
+
+log "====================arm64-v8a================="
+./build-android-arm64-v8a.sh
+log "====================armv7-eabi================"
+./build-android-armv7-eabi.sh
+log "====================x86-64===================="
+./build-android-x86-64.sh
+log "====================x86===================="
+./build-android-x86.sh
+
+
+mkdir -p apks
+
+log "https://github.com/snakers4/silero-vad/raw/master/files/silero_vad.onnx"
+
+# Download the model
+pushd ./android/SherpaOnnxVad/app/src/main/assets/
+wget https://github.com/snakers4/silero-vad/raw/master/files/silero_vad.onnx
+popd
+
+for arch in arm64-v8a armeabi-v7a x86_64 x86; do
+  log "------------------------------------------------------------"
+  log "build apk for $arch"
+  log "------------------------------------------------------------"
+  src_arch=$arch
+  if [ $arch == "armeabi-v7a" ]; then
+    src_arch=armv7-eabi
+  elif [ $arch == "x86_64" ]; then
+    src_arch=x86-64
+  fi
+
+  ls -lh ./build-android-$src_arch/install/lib/*.so
+
+  cp -v ./build-android-$src_arch/install/lib/*.so ./android/SherpaOnnxVad/app/src/main/jniLibs/$arch/
+
+  pushd ./android/SherpaOnnxVad
+  ./gradlew build
+  popd
+
+  mv android/SherpaOnnxVad/app/build/outputs/apk/debug/app-debug.apk ./apks/sherpa-onnx-${SHERPA_ONNX_VERSION}-$arch-silero-vad.apk
+  ls -lh apks
+  rm -v ./android/SherpaOnnxVad/app/src/main/jniLibs/$arch/*.so
+done
+
+rm -rf ./android/SherpaOnnxVad/app/src/main/assets/*.onnx
+
+ls -lh apks/

kotlin-api-examples/Vad.kt

@@ -0,0 +1 @@
+../android/SherpaOnnxVad/app/src/main/java/com/k2fsa/sherpa/onnx/Vad.kt

sherpa-onnx/csrc/sherpa-onnx-offline-parallel.cc

@@ -32,7 +32,7 @@ std::vector<std::vector<std::string>> SplitToBatches(
     process_num += batch_size;
   }
   if (itr != input.cend()) {
-     outputs.emplace_back(itr, input.cend());
+    outputs.emplace_back(itr, input.cend());
   }
   return outputs;
 }
@@ -41,8 +41,8 @@ std::vector<std::string> LoadScpFile(const std::string &wav_scp_path) {
   std::vector<std::string> wav_paths;
   std::ifstream in(wav_scp_path);
   if (!in.is_open()) {
-      fprintf(stderr, "Failed to open file: %s.\n", wav_scp_path.c_str());
-      return wav_paths;
+    fprintf(stderr, "Failed to open file: %s.\n", wav_scp_path.c_str());
+    return wav_paths;
   }
   std::string line, column1, column2;
   while (std::getline(in, line)) {
@@ -55,8 +55,8 @@ std::vector<std::string> LoadScpFile(const std::string &wav_scp_path) {
 }
 
 void AsrInference(const std::vector<std::vector<std::string>> &chunk_wav_paths,
-                   sherpa_onnx::OfflineRecognizer* recognizer,
-                   float* total_length, float* total_time) {
+                  sherpa_onnx::OfflineRecognizer *recognizer,
+                  float *total_length, float *total_time) {
   std::vector<std::unique_ptr<sherpa_onnx::OfflineStream>> ss;
   std::vector<sherpa_onnx::OfflineStream *> ss_pointers;
   float duration = 0.0f;
@@ -70,7 +70,7 @@ void AsrInference(const std::vector<std::vector<std::string>> &chunk_wav_paths,
         sherpa_onnx::ReadWave(wav_filename, &sampling_rate, &is_ok);
     if (!is_ok) {
       fprintf(stderr, "Failed to read %s\n", wav_filename.c_str());
-       continue;
+      continue;
     }
     duration += samples.size() / static_cast<float>(sampling_rate);
     auto s = recognizer->CreateStream();
@@ -97,7 +97,7 @@ void AsrInference(const std::vector<std::vector<std::string>> &chunk_wav_paths,
           sherpa_onnx::ReadWave(wav_filename, &sampling_rate, &is_ok);
       if (!is_ok) {
         fprintf(stderr, "Failed to read %s\n", wav_filename.c_str());
-         continue;
+        continue;
       }
       duration += samples.size() / static_cast<float>(sampling_rate);
       auto s = recognizer->CreateStream();
@@ -109,9 +109,9 @@ void AsrInference(const std::vector<std::vector<std::string>> &chunk_wav_paths,
     recognizer->DecodeStreams(ss_pointers.data(), ss_pointers.size());
     const auto end = std::chrono::steady_clock::now();
     float elapsed_seconds =
-      std::chrono::duration_cast<std::chrono::milliseconds>(end - begin)
-          .count() /
-      1000.;
+        std::chrono::duration_cast<std::chrono::milliseconds>(end - begin)
+            .count() /
+        1000.;
     elapsed_seconds_batch += elapsed_seconds;
     int i = 0;
     for (const auto &wav_filename : wav_paths) {
@@ -122,7 +122,7 @@ void AsrInference(const std::vector<std::vector<std::string>> &chunk_wav_paths,
     ss_pointers.clear();
     ss.clear();
   }
-  fprintf(stderr, "thread %lu.\n", std::this_thread::get_id());
+
   {
     std::lock_guard<std::mutex> guard(mtx);
     *total_length += duration;
@@ -132,7 +132,6 @@ void AsrInference(const std::vector<std::vector<std::string>> &chunk_wav_paths,
   }
 }
 
-
 int main(int32_t argc, char *argv[]) {
   const char *kUsageMessage = R"usage(
 Speech recognition using non-streaming models with sherpa-onnx.
@@ -223,17 +222,17 @@ https://k2-fsa.github.io/sherpa/onnx/pretrained_models/index.html
 for a list of pre-trained models to download.
 )usage";
   std::string wav_scp = "";  // file path, kaldi style wav list.
-  int32_t nj = 1;  // thread number
-  int32_t batch_size = 1; // number of wav files processed at once.
+  int32_t nj = 1;            // thread number
+  int32_t batch_size = 1;    // number of wav files processed at once.
   sherpa_onnx::ParseOptions po(kUsageMessage);
   sherpa_onnx::OfflineRecognizerConfig config;
   config.Register(&po);
   po.Register("wav-scp", &wav_scp,
               "a file including wav-id and wav-path, kaldi style wav list."
-              "default="". when it is not empty, wav files which positional "
+              "default="
+              ". when it is not empty, wav files which positional "
               "parameters provide are invalid.");
-  po.Register("nj", &nj,
-              "multi-thread num for decoding, default=1");
+  po.Register("nj", &nj, "multi-thread num for decoding, default=1");
   po.Register("batch-size", &batch_size,
               "number of wav files processed at once during the decoding"
               "process. default=1");
@@ -262,7 +261,8 @@ for a list of pre-trained models to download.
       1000.;
   fprintf(stderr,
           "Started nj: %d, batch_size: %d, wav_path: %s. recognizer init time: "
-          "%.6f\n", nj, batch_size, wav_scp.c_str(), elapsed_seconds);
+          "%.6f\n",
+          nj, batch_size, wav_scp.c_str(), elapsed_seconds);
   std::this_thread::sleep_for(std::chrono::seconds(10));  // sleep 10s
   std::vector<std::string> wav_paths;
   if (!wav_scp.empty()) {
@@ -282,12 +282,12 @@ for a list of pre-trained models to download.
   float total_length = 0.0f;
   float total_time = 0.0f;
   for (int i = 0; i < nj; i++) {
-    threads.emplace_back(std::thread(AsrInference, batch_wav_paths,
-                         &recognizer, &total_length, &total_time));
+    threads.emplace_back(std::thread(AsrInference, batch_wav_paths, &recognizer,
+                                     &total_length, &total_time));
   }
 
-  for (auto& thread : threads) {
-      thread.join();
+  for (auto &thread : threads) {
+    thread.join();
   }
 
   fprintf(stderr, "num threads: %d\n", config.model_config.num_threads);
@@ -297,8 +297,8 @@ for a list of pre-trained models to download.
   }
   fprintf(stderr, "Elapsed seconds: %.3f s\n", total_time);
   float rtf = total_time / total_length;
-  fprintf(stderr, "Real time factor (RTF): %.6f / %.6f = %.4f\n",
-          total_time, total_length, rtf);
+  fprintf(stderr, "Real time factor (RTF): %.6f / %.6f = %.4f\n", total_time,
+          total_length, rtf);
   fprintf(stderr, "SPEEDUP: %.4f\n", 1.0 / rtf);
 
   return 0;

sherpa-onnx/csrc/silero-vad-model.cc

@@ -37,6 +37,29 @@ class SileroVadModel::Impl {
     min_speech_samples_ = sample_rate_ * config_.silero_vad.min_speech_duration;
   }
 
+#if __ANDROID_API__ >= 9
+  Impl(AAssetManager *mgr, const VadModelConfig &config)
+      : config_(config),
+        env_(ORT_LOGGING_LEVEL_ERROR),
+        sess_opts_(GetSessionOptions(config)),
+        allocator_{} {
+    auto buf = ReadFile(mgr, config.silero_vad.model);
+    Init(buf.data(), buf.size());
+
+    sample_rate_ = config.sample_rate;
+    if (sample_rate_ != 16000) {
+      SHERPA_ONNX_LOGE("Expected sample rate 16000. Given: %d",
+                       config.sample_rate);
+      exit(-1);
+    }
+
+    min_silence_samples_ =
+        sample_rate_ * config_.silero_vad.min_silence_duration;
+
+    min_speech_samples_ = sample_rate_ * config_.silero_vad.min_speech_duration;
+  }
+#endif
+
   void Reset() {
     // 2 - number of LSTM layer
     // 1 - batch size
@@ -260,6 +283,11 @@ class SileroVadModel::Impl {
 SileroVadModel::SileroVadModel(const VadModelConfig &config)
     : impl_(std::make_unique<Impl>(config)) {}
 
+#if __ANDROID_API__ >= 9
+SileroVadModel::SileroVadModel(AAssetManager *mgr, const VadModelConfig &config)
+    : impl_(std::make_unique<Impl>(mgr, config)) {}
+#endif
+
 SileroVadModel::~SileroVadModel() = default;
 
 void SileroVadModel::Reset() { return impl_->Reset(); }

sherpa-onnx/csrc/silero-vad-model.h

@@ -6,6 +6,11 @@
 
 #include <memory>
 
+#if __ANDROID_API__ >= 9
+#include "android/asset_manager.h"
+#include "android/asset_manager_jni.h"
+#endif
+
 #include "sherpa-onnx/csrc/vad-model.h"
 
 namespace sherpa_onnx {
@@ -13,6 +18,11 @@ namespace sherpa_onnx {
 class SileroVadModel : public VadModel {
  public:
   explicit SileroVadModel(const VadModelConfig &config);
+
+#if __ANDROID_API__ >= 9
+  SileroVadModel(AAssetManager *mgr, const VadModelConfig &config);
+#endif
+
   ~SileroVadModel() override;
 
   // reset the internal model states

sherpa-onnx/csrc/vad-model.cc

@@ -13,4 +13,12 @@ std::unique_ptr<VadModel> VadModel::Create(const VadModelConfig &config) {
   return std::make_unique<SileroVadModel>(config);
 }
 
+#if __ANDROID_API__ >= 9
+std::unique_ptr<VadModel> VadModel::Create(AAssetManager *mgr,
+                                           const VadModelConfig &config) {
+  // TODO(fangjun): Support other VAD models.
+  return std::make_unique<SileroVadModel>(mgr, config);
+}
+#endif
+
 }  // namespace sherpa_onnx

sherpa-onnx/csrc/vad-model.h

@@ -6,6 +6,11 @@
 
 #include <memory>
 
+#if __ANDROID_API__ >= 9
+#include "android/asset_manager.h"
+#include "android/asset_manager_jni.h"
+#endif
+
 #include "sherpa-onnx/csrc/vad-model-config.h"
 
 namespace sherpa_onnx {
@@ -16,6 +21,11 @@ class VadModel {
 
   static std::unique_ptr<VadModel> Create(const VadModelConfig &config);
 
+#if __ANDROID_API__ >= 9
+  static std::unique_ptr<VadModel> Create(AAssetManager *mgr,
+                                          const VadModelConfig &config);
+#endif
+
   // reset the internal model states
   virtual void Reset() = 0;
 

sherpa-onnx/csrc/voice-activity-detector.cc

@@ -19,10 +19,32 @@ class VoiceActivityDetector::Impl {
         config_(config),
         buffer_(buffer_size_in_seconds * config.sample_rate) {}
 
-  void AcceptWaveform(const float *samples, int32_t n) {
-    buffer_.Push(samples, n);
+#if __ANDROID_API__ >= 9
+  Impl(AAssetManager *mgr, const VadModelConfig &config,
+       float buffer_size_in_seconds = 60)
+      : model_(VadModel::Create(mgr, config)),
+        config_(config),
+        buffer_(buffer_size_in_seconds * config.sample_rate) {}
+#endif
+
+  void AcceptWaveform(const float *samples, int32_t n) {
+    int32_t window_size = model_->WindowSize();
+
+    // note n is usally window_size and there is no need to use
+    // an extra buffer here
+    last_.insert(last_.end(), samples, samples + n);
+    int32_t k = static_cast<int32_t>(last_.size()) / window_size;
+    const float *p = last_.data();
+    bool is_speech = false;
+
+    for (int32_t i = 0; i != k; ++i, p += window_size) {
+      buffer_.Push(p, window_size);
+      is_speech = model_->IsSpeech(p, window_size);
+    }
+
+    last_ = std::vector<float>(
+        p, static_cast<const float *>(last_.data()) + last_.size());
 
-    bool is_speech = model_->IsSpeech(samples, n);
     if (is_speech) {
       if (start_ == -1) {
         // beginning of speech
@@ -31,15 +53,15 @@ class VoiceActivityDetector::Impl {
       }
     } else {
       // non-speech
-      if (start_ != -1) {
+      if (start_ != -1 && buffer_.Size()) {
         // end of speech, save the speech segment
         int32_t end = buffer_.Tail() - model_->MinSilenceDurationSamples();
 
-        std::vector<float> samples = buffer_.Get(start_, end - start_);
+        std::vector<float> s = buffer_.Get(start_, end - start_);
         SpeechSegment segment;
 
         segment.start = start_;
-        segment.samples = std::move(samples);
+        segment.samples = std::move(s);
 
         segments_.push(std::move(segment));
 
@@ -73,6 +95,7 @@ class VoiceActivityDetector::Impl {
   std::unique_ptr<VadModel> model_;
   VadModelConfig config_;
   CircularBuffer buffer_;
+  std::vector<float> last_;
 
   int32_t start_ = -1;
 };
@@ -81,6 +104,13 @@ VoiceActivityDetector::VoiceActivityDetector(
     const VadModelConfig &config, float buffer_size_in_seconds /*= 60*/)
     : impl_(std::make_unique<Impl>(config, buffer_size_in_seconds)) {}
 
+#if __ANDROID_API__ >= 9
+VoiceActivityDetector::VoiceActivityDetector(
+    AAssetManager *mgr, const VadModelConfig &config,
+    float buffer_size_in_seconds /*= 60*/)
+    : impl_(std::make_unique<Impl>(mgr, config, buffer_size_in_seconds)) {}
+#endif
+
 VoiceActivityDetector::~VoiceActivityDetector() = default;
 
 void VoiceActivityDetector::AcceptWaveform(const float *samples, int32_t n) {

sherpa-onnx/csrc/voice-activity-detector.h

@@ -7,6 +7,11 @@
 #include <memory>
 #include <vector>
 
+#if __ANDROID_API__ >= 9
+#include "android/asset_manager.h"
+#include "android/asset_manager_jni.h"
+#endif
+
 #include "sherpa-onnx/csrc/vad-model-config.h"
 
 namespace sherpa_onnx {
@@ -20,6 +25,12 @@ class VoiceActivityDetector {
  public:
   explicit VoiceActivityDetector(const VadModelConfig &config,
                                  float buffer_size_in_seconds = 60);
+
+#if __ANDROID_API__ >= 9
+  VoiceActivityDetector(AAssetManager *mgr, const VadModelConfig &config,
+                        float buffer_size_in_seconds = 60);
+#endif
+
   ~VoiceActivityDetector();
 
   void AcceptWaveform(const float *samples, int32_t n);

sherpa-onnx/jni/jni.cc

@@ -23,6 +23,7 @@
 #include "sherpa-onnx/csrc/offline-recognizer.h"
 #include "sherpa-onnx/csrc/online-recognizer.h"
 #include "sherpa-onnx/csrc/onnx-utils.h"
+#include "sherpa-onnx/csrc/voice-activity-detector.h"
 #include "sherpa-onnx/csrc/wave-reader.h"
 
 #define SHERPA_ONNX_EXTERN_C extern "C"
@@ -106,6 +107,33 @@ class SherpaOnnxOffline {
   OfflineRecognizer recognizer_;
 };
 
+class SherpaOnnxVad {
+ public:
+#if __ANDROID_API__ >= 9
+  SherpaOnnxVad(AAssetManager *mgr, const VadModelConfig &config)
+      : vad_(mgr, config) {}
+#endif
+
+  explicit SherpaOnnxVad(const VadModelConfig &config) : vad_(config) {}
+
+  void AcceptWaveform(const float *samples, int32_t n) {
+    vad_.AcceptWaveform(samples, n);
+  }
+
+  bool Empty() const { return vad_.Empty(); }
+
+  void Pop() { vad_.Pop(); }
+
+  const SpeechSegment &Front() const { return vad_.Front(); }
+
+  bool IsSpeechDetected() const { return vad_.IsSpeechDetected(); }
+
+  void Reset() { vad_.Reset(); }
+
+ private:
+  VoiceActivityDetector vad_;
+};
+
 static OnlineRecognizerConfig GetConfig(JNIEnv *env, jobject config) {
   OnlineRecognizerConfig ans;
 
@@ -411,8 +439,165 @@ static OfflineRecognizerConfig GetOfflineConfig(JNIEnv *env, jobject config) {
   return ans;
 }
 
+static VadModelConfig GetVadModelConfig(JNIEnv *env, jobject config) {
+  VadModelConfig ans;
+
+  jclass cls = env->GetObjectClass(config);
+  jfieldID fid;
+
+  // silero_vad
+  fid = env->GetFieldID(cls, "sileroVadModelConfig",
+                        "Lcom/k2fsa/sherpa/onnx/SileroVadModelConfig;");
+  jobject silero_vad_config = env->GetObjectField(config, fid);
+  jclass silero_vad_config_cls = env->GetObjectClass(silero_vad_config);
+
+  fid = env->GetFieldID(silero_vad_config_cls, "model", "Ljava/lang/String;");
+  auto s = (jstring)env->GetObjectField(silero_vad_config, fid);
+  auto p = env->GetStringUTFChars(s, nullptr);
+  ans.silero_vad.model = p;
+  env->ReleaseStringUTFChars(s, p);
+
+  fid = env->GetFieldID(silero_vad_config_cls, "threshold", "F");
+  ans.silero_vad.threshold = env->GetFloatField(silero_vad_config, fid);
+
+  fid = env->GetFieldID(silero_vad_config_cls, "minSilenceDuration", "F");
+  ans.silero_vad.min_silence_duration =
+      env->GetFloatField(silero_vad_config, fid);
+
+  fid = env->GetFieldID(silero_vad_config_cls, "minSpeechDuration", "F");
+  ans.silero_vad.min_speech_duration =
+      env->GetFloatField(silero_vad_config, fid);
+
+  fid = env->GetFieldID(silero_vad_config_cls, "windowSize", "I");
+  ans.silero_vad.window_size = env->GetIntField(silero_vad_config, fid);
+
+  fid = env->GetFieldID(cls, "sampleRate", "I");
+  ans.sample_rate = env->GetIntField(config, fid);
+
+  fid = env->GetFieldID(cls, "numThreads", "I");
+  ans.num_threads = env->GetIntField(config, fid);
+
+  fid = env->GetFieldID(cls, "provider", "Ljava/lang/String;");
+  s = (jstring)env->GetObjectField(config, fid);
+  p = env->GetStringUTFChars(s, nullptr);
+  ans.provider = p;
+  env->ReleaseStringUTFChars(s, p);
+
+  fid = env->GetFieldID(cls, "debug", "Z");
+  ans.debug = env->GetBooleanField(config, fid);
+
+  return ans;
+}
+
 }  // namespace sherpa_onnx
 
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT jlong JNICALL Java_com_k2fsa_sherpa_onnx_Vad_new(
+    JNIEnv *env, jobject /*obj*/, jobject asset_manager, jobject _config) {
+#if __ANDROID_API__ >= 9
+  AAssetManager *mgr = AAssetManager_fromJava(env, asset_manager);
+  if (!mgr) {
+    SHERPA_ONNX_LOGE("Failed to get asset manager: %p", mgr);
+  }
+#endif
+  auto config = sherpa_onnx::GetVadModelConfig(env, _config);
+  SHERPA_ONNX_LOGE("config:\n%s", config.ToString().c_str());
+  auto model = new sherpa_onnx::SherpaOnnxVad(
+#if __ANDROID_API__ >= 9
+      mgr,
+#endif
+      config);
+
+  return (jlong)model;
+}
+
+JNIEXPORT jlong JNICALL Java_com_k2fsa_sherpa_onnx_Vad_newFromFile(
+    JNIEnv *env, jobject /*obj*/, jobject _config) {
+  auto config = sherpa_onnx::GetVadModelConfig(env, _config);
+  SHERPA_ONNX_LOGE("config:\n%s", config.ToString().c_str());
+  auto model = new sherpa_onnx::SherpaOnnxVad(config);
+
+  return (jlong)model;
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT void JNICALL Java_com_k2fsa_sherpa_onnx_Vad_delete(JNIEnv *env,
+                                                             jobject /*obj*/,
+                                                             jlong ptr) {
+  delete reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr);
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT void JNICALL Java_com_k2fsa_sherpa_onnx_Vad_acceptWaveform(
+    JNIEnv *env, jobject /*obj*/, jlong ptr, jfloatArray samples) {
+  auto model = reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr);
+
+  jfloat *p = env->GetFloatArrayElements(samples, nullptr);
+  jsize n = env->GetArrayLength(samples);
+
+  model->AcceptWaveform(p, n);
+
+  env->ReleaseFloatArrayElements(samples, p, JNI_ABORT);
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT bool JNICALL Java_com_k2fsa_sherpa_onnx_Vad_empty(JNIEnv *env,
+                                                            jobject /*obj*/,
+                                                            jlong ptr) {
+  auto model = reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr);
+  return model->Empty();
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT void JNICALL Java_com_k2fsa_sherpa_onnx_Vad_pop(JNIEnv *env,
+                                                          jobject /*obj*/,
+                                                          jlong ptr) {
+  auto model = reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr);
+  model->Pop();
+}
+
+// see
+// https://stackoverflow.com/questions/29043872/android-jni-return-multiple-variables
+static jobject NewInteger(JNIEnv *env, int32_t value) {
+  jclass cls = env->FindClass("java/lang/Integer");
+  jmethodID constructor = env->GetMethodID(cls, "<init>", "(I)V");
+  return env->NewObject(cls, constructor, value);
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT jobjectArray JNICALL
+Java_com_k2fsa_sherpa_onnx_Vad_front(JNIEnv *env, jobject /*obj*/, jlong ptr) {
+  const auto &front =
+      reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr)->Front();
+
+  jfloatArray samples_arr = env->NewFloatArray(front.samples.size());
+  env->SetFloatArrayRegion(samples_arr, 0, front.samples.size(),
+                           front.samples.data());
+
+  jobjectArray obj_arr = (jobjectArray)env->NewObjectArray(
+      2, env->FindClass("java/lang/Object"), nullptr);
+
+  env->SetObjectArrayElement(obj_arr, 0, NewInteger(env, front.start));
+  env->SetObjectArrayElement(obj_arr, 1, samples_arr);
+
+  return obj_arr;
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT bool JNICALL Java_com_k2fsa_sherpa_onnx_Vad_isSpeechDetected(
+    JNIEnv *env, jobject /*obj*/, jlong ptr) {
+  auto model = reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr);
+  return model->IsSpeechDetected();
+}
+
+SHERPA_ONNX_EXTERN_C
+JNIEXPORT void JNICALL Java_com_k2fsa_sherpa_onnx_Vad_reset(JNIEnv *env,
+                                                            jobject /*obj*/,
+                                                            jlong ptr) {
+  auto model = reinterpret_cast<sherpa_onnx::SherpaOnnxVad *>(ptr);
+  model->Reset();
+}
+
 SHERPA_ONNX_EXTERN_C
 JNIEXPORT jlong JNICALL Java_com_k2fsa_sherpa_onnx_SherpaOnnx_new(
     JNIEnv *env, jobject /*obj*/, jobject asset_manager, jobject _config) {
@@ -564,12 +749,12 @@ SHERPA_ONNX_EXTERN_C
 JNIEXPORT jobjectArray JNICALL Java_com_k2fsa_sherpa_onnx_SherpaOnnx_getTokens(
     JNIEnv *env, jobject /*obj*/, jlong ptr) {
   auto tokens = reinterpret_cast<sherpa_onnx::SherpaOnnx *>(ptr)->GetTokens();
-  int size = tokens.size();
+  int32_t size = tokens.size();
   jclass stringClass = env->FindClass("java/lang/String");
 
   // convert C++ list into jni string array
   jobjectArray result = env->NewObjectArray(size, stringClass, NULL);
-  for (int i = 0; i < size; i++) {
+  for (int32_t i = 0; i < size; i++) {
     // Convert the C++ string to a C string
     const char *cstr = tokens[i].c_str();
 
@@ -583,14 +768,6 @@ JNIEXPORT jobjectArray JNICALL Java_com_k2fsa_sherpa_onnx_SherpaOnnx_getTokens(
   return result;
 }
 
-// see
-// https://stackoverflow.com/questions/29043872/android-jni-return-multiple-variables
-static jobject NewInteger(JNIEnv *env, int32_t value) {
-  jclass cls = env->FindClass("java/lang/Integer");
-  jmethodID constructor = env->GetMethodID(cls, "<init>", "(I)V");
-  return env->NewObject(cls, constructor, value);
-}
-
 static jobjectArray ReadWaveImpl(JNIEnv *env, std::istream &is,
                                  const char *p_filename) {
   bool is_ok = false;