Add VAD and keyword spotting for the Node package with WebAssembly (#1286)

nodejs-examples/test-keyword-spotter-transducer.js

@@ -0,0 +1,49 @@
+// Copyright (c)  2024  Xiaomi Corporation
+const sherpa_onnx = require('sherpa-onnx');
+
+function createKeywordSpotter() {
+  // Please download test files from
+  // https://github.com/k2-fsa/sherpa-onnx/releases/tag/kws-models
+  const config = {
+    'modelConfig': {
+      'transducer': {
+        'encoder':
+            './sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/encoder-epoch-12-avg-2-chunk-16-left-64.onnx',
+        'decoder':
+            './sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/decoder-epoch-12-avg-2-chunk-16-left-64.onnx',
+        'joiner':
+            './sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/joiner-epoch-12-avg-2-chunk-16-left-64.onnx',
+      },
+      'tokens':
+          './sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/tokens.txt',
+    },
+    keywords: 'w én s ēn t è k ǎ s uǒ  @文森特卡索\n' +
+        'f ǎ g uó @法国'
+  };
+
+  return sherpa_onnx.createKws(config);
+}
+
+const kws = createKeywordSpotter();
+const stream = kws.createStream();
+const waveFilename =
+    './sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01/test_wavs/3.wav';
+
+const wave = sherpa_onnx.readWave(waveFilename);
+stream.acceptWaveform(wave.sampleRate, wave.samples);
+
+const tailPadding = new Float32Array(wave.sampleRate * 0.4);
+stream.acceptWaveform(kws.config.featConfig.sampleRate, tailPadding);
+
+const detectedKeywords = [];
+while (kws.isReady(stream)) {
+  kws.decode(stream);
+  const keyword = kws.getResult(stream).keyword;
+  if (keyword != '') {
+    detectedKeywords.push(keyword);
+  }
+}
+console.log(detectedKeywords);
+
+stream.free();
+kws.free();