Add node-addon-api for VAD (#864)

scripts/node-addon-api/lib/sherpa-onnx.js

@@ -1,8 +1,12 @@
 const addon = require('./addon.js')
 const streaming_asr = require('./streaming-asr.js');
+const vad = require('./vad.js');
 
 module.exports = {
   OnlineRecognizer: streaming_asr.OnlineRecognizer,
   readWave: addon.readWave,
+  writeWave: addon.writeWave,
   Display: streaming_asr.Display,
+  Vad: vad.Vad,
+  CircularBuffer: vad.CircularBuffer,
 }

scripts/node-addon-api/lib/streaming-asr.js

@@ -15,10 +15,11 @@ class OnlineStream {
     this.handle = handle;
   }
 
+  // obj is {samples: samples, sampleRate: sampleRate}
   // samples is a float32 array containing samples in the range [-1, 1]
-  acceptWaveform(samples, sampleRate) {
-    addon.acceptWaveformOnline(
-        this.handle, {samples: samples, sampleRate: sampleRate})
+  // sampleRate is a number
+  acceptWaveform(obj) {
+    addon.acceptWaveformOnline(this.handle, obj)
   }
 
   inputFinished() {

scripts/node-addon-api/lib/vad.js

@@ -0,0 +1,88 @@
+const addon = require('./addon.js');
+
+class CircularBuffer {
+  constructor(capacity) {
+    this.handle = addon.createCircularBuffer(capacity);
+  }
+
+  // samples is a float32 array
+  push(samples) {
+    addon.circularBufferPush(this.handle, samples);
+  }
+
+  // return a float32 array
+  get(startIndex, n) {
+    return addon.circularBufferGet(this.handle, startIndex, n);
+  }
+
+  pop(n) {
+    return addon.circularBufferPop(this.handle, n);
+  }
+
+  size() {
+    return addon.circularBufferSize(this.handle);
+  }
+
+  head() {
+    return addon.circularBufferHead(this.handle);
+  }
+
+  reset() {
+    return addon.circularBufferReset(this.handle);
+  }
+}
+
+class Vad {
+  /*
+config = {
+  sileroVad: {
+    model: "./silero_vad.onnx",
+    threshold: 0.5,
+  }
+}
+   */
+  constructor(config, bufferSizeInSeconds) {
+    this.handle =
+        addon.createVoiceActivityDetector(config, bufferSizeInSeconds);
+    this.config = config;
+  }
+
+  acceptWaveform(samples) {
+    addon.voiceActivityDetectorAcceptWaveform(this.handle, samples)
+  }
+
+  isEmpty() {
+    return addon.voiceActivityDetectorIsEmpty(this.handle)
+  }
+
+  isDetected() {
+    return addon.voiceActivityDetectorIsDetected(this.handle)
+  }
+
+  pop() {
+    addon.voiceActivityDetectorPop(this.handle)
+  }
+
+  clear() {
+    addon.VoiceActivityDetectorClearWrapper(this.handle)
+  }
+
+  /*
+{
+  samples: a 1-d float32 array,
+  start: a int32
+}
+   */
+  front() {
+    return addon.voiceActivityDetectorFront(this.handle)
+  }
+
+  reset() {
+    return addon.VoiceActivityDetectorResetWrapper(this.handle)
+  }
+}
+
+module.exports = {
+  Vad,
+  CircularBuffer,
+}