录音 voice record

  "compilerOptions": {"types": [
      "node"
    ]
  },

startRecord() {
  navigator.mediaDevices.getUserMedia({ audio: true }).then((stream) => {
    let recordRTC = RecordRTC(stream, {
      type: ‘audio‘,
      recorderType: RecordRTC.StereoAudioRecorder,
      disableLogs: true 
      //leftChannel: true,
      //numberOfAudioChannels: 1 // or leftChannel:true
    });
    recordRTC.startRecording();
    this.recordRTC = recordRTC;
    this.stream = stream;
  }).catch(() => {
    console.log(‘user no allow‘);
  });
}

 stop() {
    let recordRTC = this.recordRTC;
    recordRTC.stopRecording(() => {    
      // 关闭 html5 navigator.mediaDevices.getUserMedia
      var track = this.stream.getTracks()[0]; // 0 是因为我们只有一个 track, 是可以 track 2 个的, 声音和影像
      track.stop();

      // ff 可以 skip 掉 fileReader, 直接拿 recordRTC.blob new File 也可以, 因为 ff 返回的就是 ogg 了 
      // 下面是针对 chrome 返回的是 wav, 很大, 所以使用 ffmpeg 压缩去 ogg 
      let fileReader = new FileReader();

      fileReader.onload = () => {
        recordRTC.clearRecordedData(); // reader 读出来后就可以释放 recordRTC 了. 

        //压缩是很慢的, 所以要另开一个线程
        var WorkerConstructor = require("worker-loader!./worker2.js"); 
        var worker = new WorkerConstructor();

        worker.onmessage = (e) => {
          var result = e.data[0];
          // edge 不可以跑哦, 只有 chrome and ff ok 
          var blob = new File([result.data], ‘whatever.ogg‘, {
            type: ‘audio/ogg‘
          });
          
          let formData = new FormData();
          formData.append(‘uploadFile‘, blob, ‘whatever.ogg‘);

          // 上传
          this.http.post(‘/api/uploadFile‘, formData).subscribe(() => {
            console.log(‘done‘);
          });

          // 做成 audio 
          let audio = new Audio();
          audio.controls = true;
          let url = window.URL.createObjectURL(blob);
          
          audio.src = url;
          let recordMp3Container = document.getElementById(‘recordmp3-container‘);
          recordMp3Container.appendChild(audio);
          audio.play();

          // 关闭 worker 
          worker.terminate(); 
        };
    
        worker.postMessage(fileReader.result);
      };

      fileReader.readAsArrayBuffer(recordRTC.blob); 
    });
  }

let url = require("file-loader!./ffmpeg_asm.js");  

self.importScripts(url);

let print = () => { };
self.onmessage = (event) => {
    let blob = event.data;
    let result = ffmpeg_run({
        print: print,
        printErr: print,
        files: [
            {
                data: new Uint8Array(blob),
                name: "whatever.wav"
            }
        ],
        arguments: ‘-i whatever.wav -c:a vorbis -b:a 4800k -strict experimental output.ogg‘.split(‘ ‘)
    });
    self.postMessage(result);
};

//var url = require("file-loader!./lame.all.js");
var url = require("file-loader!lamejs/lame.all.js");  

self.importScripts(url);

self.onmessage = function (e) {
    let stream = e.data.stream;
    let streamArray = new Int16Array(stream);
    streamArray = streamArray.slice(50); //去掉一开始的杂音
    let buffer = [];
    let mp3encoder = new lamejs.Mp3Encoder(1, 44100, 128);

    let mp3Data = mp3encoder.encodeBuffer(streamArray);
    buffer.push(mp3Data);
    mp3Data = mp3encoder.flush(); //获取最后一个 part
    buffer.push(mp3Data);
    let blob = new Blob(buffer, { type: ‘audio/mp3‘ });
    var workerResult = {
        stream: blob
    };
    self.postMessage(workerResult);
}