Refactor the JNI interface to make it more modular and maintainable (#802)

sherpa-onnx/kotlin-api/Vad.kt

@@ -0,0 +1,104 @@
+// 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 = newFromAsset(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 clear() = clear(ptr)
+
+    fun isSpeechDetected(): Boolean = isSpeechDetected(ptr)
+
+    fun reset() = reset(ptr)
+
+    private external fun delete(ptr: Long)
+
+    private external fun newFromAsset(
+        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 clear(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;
+}