Add Kotlin API for speech enhancement GTCRN models (#2008)

sherpa-onnx/kotlin-api/OfflineSpeechDenoiser.kt

@@ -0,0 +1,82 @@
+package com.k2fsa.sherpa.onnx
+
+import android.content.res.AssetManager
+
+data class OfflineSpeechDenoiserGtcrnModelConfig(
+    var model: String = "",
+)
+
+data class OfflineSpeechDenoiserModelConfig(
+    var gtcrn: OfflineSpeechDenoiserGtcrnModelConfig = OfflineSpeechDenoiserGtcrnModelConfig(),
+    var numThreads: Int = 1,
+    var debug: Boolean = false,
+    var provider: String = "cpu",
+)
+
+data class OfflineSpeechDenoiserConfig(
+    var model: OfflineSpeechDenoiserModelConfig = OfflineSpeechDenoiserModelConfig(),
+)
+
+class DenoisedAudio(
+    val samples: FloatArray,
+    val sampleRate: Int,
+) {
+    fun save(filename: String) =
+        saveImpl(filename = filename, samples = samples, sampleRate = sampleRate)
+
+    private external fun saveImpl(
+        filename: String,
+        samples: FloatArray,
+        sampleRate: Int
+    ): Boolean
+}
+
+class OfflineSpeechDenoiser(
+    assetManager: AssetManager? = null,
+    config: OfflineSpeechDenoiserConfig,
+) {
+    private var ptr: Long
+
+    init {
+        ptr = if (assetManager != null) {
+            newFromAsset(assetManager, config)
+        } else {
+            newFromFile(config)
+        }
+    }
+
+    protected fun finalize() {
+        if (ptr != 0L) {
+            delete(ptr)
+            ptr = 0
+        }
+    }
+
+    fun release() = finalize()
+
+    fun run(samples: FloatArray, sampleRate: Int) = run(ptr, samples, sampleRate)
+
+    val sampleRate
+      get() = getSampleRate(ptr)
+
+    private external fun newFromAsset(
+        assetManager: AssetManager,
+        config: OfflineSpeechDenoiserConfig,
+    ): Long
+
+    private external fun newFromFile(
+        config: OfflineSpeechDenoiserConfig,
+    ): Long
+
+    private external fun delete(ptr: Long)
+
+    private external fun run(ptr: Long, samples: FloatArray, sampleRate: Int): DenoisedAudio
+
+    private external fun getSampleRate(ptr: Long): Int
+
+    companion object {
+        init {
+            System.loadLibrary("sherpa-onnx-jni")
+        }
+    }
+}