Invia registratore audio microfono dal browser a Google speech al testo-Javascript

@terry-lennox grazie mille. Per la risposta chiara.

Ma sto usando React come Front-End, quindi ho un pacchetto npm chiamato recorder-js

E il codice è per riferimento che vedono questo post in futuro.

import Recorder from 'recorder-js';

import micGrey from './mic-grey.svg';
import micWhite from './mic-white.svg';

import './App.css';

var recorder = null;
var audioStream = null;

class App extends Component {
  constructor(props) {
    super(props);
    this.mic = React.createRef();

    this.accessMic = this.accessMic.bind(this);
    this.handleClick = this.handleClick.bind(this);
    this.handleClick = this.handleClick.bind(this);
    this.handleSuccess = this.handleSuccess.bind(this);

    this.stopAccessingMic = this.stopAccessingMic.bind(this);
    this.getTextFromGoogle = this.getTextFromGoogle.bind(this);

    this.state = {
      isMicActive: false
    };
  }

  accessMic() {
    const audioContext = new (window.AudioContext ||
      window.webkitAudioContext)();

    recorder = new Recorder(audioContext);

    navigator.mediaDevices
      .getUserMedia({ audio: true })
      .then(this.handleSuccess)
      .catch(err => console.log('Uh oh... unable to get stream...', err));
  }

  handleSuccess(stream) {
    audioStream = stream;

    recorder.init(stream);
    recorder.start();
  }

  getTextFromGoogle(blob) {
    let filename = new Date().toISOString();
    let xhr = new XMLHttpRequest();
    xhr.onload = function(e) {
      if (this.readyState === 4) {
        console.log(e.target.responseText);
      }
    };
    let formData = new FormData();
    formData.append('audio_data', blob, filename);
    xhr.open('POST', 'http://localhost:3000/', true);
    xhr.send(formData);
  }

  handleClick() {
    const isMicActive = this.state.isMicActive;

    this.setState({
      isMicActive: !isMicActive
    });

    if (!isMicActive) {
      this.checkPermissions();
      this.accessMic();
    } else {
      this.stopAccessingMic();
    }
  }

  stopAccessingMic() {
    audioStream && audioStream.getTracks()[0].stop();
    recorder.stop().then(({ blob, buffer }) => {
      this.getTextFromGoogle(blob);
    });
  }

  checkPermissions() {
    navigator.permissions
      .query({ name: 'microphone' })
      .then(permissionObj => {
        console.log('Permission status - ', permissionObj.state);
      })
      .catch(error => {
        console.log('Permission status - Got error :', error);
      });
  }

  render() {
    return (
      <div className='App'>
        <div
          id='mic'
          ref={this.mic}
          onClick={this.handleClick}
          className={
            this.state.isMicActive ? 'mic-btn mic-btn-active' : 'mic-btn'
          }
        >
          <img src={this.state.isMicActive ? micWhite : micGrey} alt='mic' />
        </div>
      </div>
    );
  }
}
export default App;

E il codice back-end per il riferimento, c'è stato un piccolo cambiamento che stavo affrontando e l'errore è Deve usare l'audio a canale singolo (mono) per risolvere questo problema ho fatto riferimento Link, Collegamento . È necessario aggiungere audioChannelCount: 2 in config.

var router = express.Router();
const multer = require('multer');
const fs = require('fs');

const upload = multer();

process.env.GOOGLE_APPLICATION_CREDENTIALS =
  'C:/Users/user/Desktop/Speech-to-Text-e851cb3889e5.json';

/* GET home page. */
router.post('/', upload.any(), async (req, res, next) => {
  console.log('Getting text transcription..');
  try {
    let transcription = await testGoogleTextToSpeech(req.files[0].buffer);
    console.log('Text transcription: ' + transcription);
    res.status(200).send(transcription);
  } catch (error) {
    console.log(error);
    res.status(400).send(error);
  }
});

async function testGoogleTextToSpeech(audioBuffer) {
  const speech = require('@google-cloud/speech');
  const client = new speech.SpeechClient();

  const audio = {
    content: audioBuffer.toString('base64')
  };
  const config = {
    languageCode: 'en-US',
    audioChannelCount: 2
  };
  const request = {
    audio: audio,
    config: config
  };

  try {
    const [response] = await client.recognize(request);
    const transcription = response.results
      .map(result => result.alternatives[0].transcript)
      .join('\n');
    return transcription;
  } catch (error) {
    return error;
  }
}
module.exports = router;