sherpa-ncnn/nodejs-examples/real-time-speech-recognition-microphone.js

// Copyright (c)  2024  Xiaomi Corporation (authors: Fangjun Kuang)
//
const portAudio = require('naudiodon2');
// console.log(portAudio.getDevices());

const sherpa_ncnn = require('sherpa-ncnn');

function createRecognizer() {
  let modelConfig = {
    encoderParam:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/encoder_jit_trace-pnnx.ncnn.param',
    encoderBin:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/encoder_jit_trace-pnnx.ncnn.bin',
    decoderParam:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/decoder_jit_trace-pnnx.ncnn.param',
    decoderBin:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/decoder_jit_trace-pnnx.ncnn.bin',
    joinerParam:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/joiner_jit_trace-pnnx.ncnn.param',
    joinerBin:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/joiner_jit_trace-pnnx.ncnn.bin',
    tokens:
        './sherpa-ncnn-streaming-zipformer-bilingual-zh-en-2023-02-13/tokens.txt',
    useVulkanCompute: 0,
    numThreads: 1,
  };

  let decoderConfig = {
    decodingMethod: 'greedy_search',
    numActivePaths: 4,
  };

  let featConfig = {
    samplingRate: 16000,
    featureDim: 80,
  };

  let config = {
    featConfig: featConfig,
    modelConfig: modelConfig,
    decoderConfig: decoderConfig,
    enableEndpoint: 1,
    rule1MinTrailingSilence: 1.2,
    rule2MinTrailingSilence: 2.4,
    rule3MinUtternceLength: 20,
  };

  return sherpa_ncnn.createRecognizer(config);
}

const recognizer = createRecognizer();
const stream = recognizer.createStream();

let lastText = '';
let segmentIndex = 0;

const ai = new portAudio.AudioIO({
  inOptions: {
    channelCount: 1,
    closeOnError: true,  // Close the stream if an audio error is detected, if
                         // set false then just log the error
    deviceId: -1,  // Use -1 or omit the deviceId to select the default device
    sampleFormat: portAudio.SampleFormatFloat32,
    sampleRate: recognizer.config.featConfig.samplingRate
  }
});

ai.on('data', data => {
  const samples = new Float32Array(data.buffer);

  stream.acceptWaveform(recognizer.config.featConfig.samplingRate, samples);

  while (recognizer.isReady(stream)) {
    recognizer.decode(stream);
  }

  const isEndpoint = recognizer.isEndpoint(stream);
  const text = recognizer.getResult(stream);

  if (text.length > 0 && lastText != text) {
    lastText = text;
    console.log(segmentIndex, lastText);
  }
  if (isEndpoint) {
    if (text.length > 0) {
      lastText = text;
      segmentIndex += 1;
    }
    recognizer.reset(stream)
  }
});

ai.on('close', () => {
  console.log('Free resources');
  stream.free();
  recognizer.free();
});

ai.start();
console.log('Started! Please speak')