I'm trying to record audio from a website user and save the audio to my server. Many of the posts I have studied so far have referenced Matt Diamond's recorderjs. I attempted to recreate the demo at .html by opening the source code through my browser. I copied the html, "audiodisplay.js", "recorder.js", and "main.js" and put them on my server. I also added the "recorderWorker.js" file from his GitHub site. In the recorder.js file, I changed var WORKER_PATH = 'js/recorderjs/recorderWorker.js' to var WORKER_PATH = 'recorderWorker.js';

When I run the demo I set up, I'm getting the "would you like to share your microphone.." warning and I can start the recording by pressing the mic icon on the right side. However, when I stop recording, the audio waveform doesn't show up below like in Matt's demo and the save icon doesn't become activated.

If I can get the demo up and running, the next problem I have is saving the wav file to the server instead of locally like in the demo. I've found several posts saying to use XMLHttpRequest(), however I can't really figure out how to connect those examples to recorderjs. Saving WAV File Recorded in Chrome to Server HTML5 & getUserMedia - Record Audio & Save to Web Server after Certain Time RecorderJS uploading recorded blob via AJAX

I'm trying to record audio from a website user and save the audio to my server. Many of the posts I have studied so far have referenced Matt Diamond's recorderjs. I attempted to recreate the demo at http://webaudiodemos.appspot.com/AudioRecorder/index.html by opening the source code through my browser. I copied the html, "audiodisplay.js", "recorder.js", and "main.js" and put them on my server. I also added the "recorderWorker.js" file from his GitHub site. In the recorder.js file, I changed var WORKER_PATH = 'js/recorderjs/recorderWorker.js' to var WORKER_PATH = 'recorderWorker.js';

When I run the demo I set up, I'm getting the "would you like to share your microphone.." warning and I can start the recording by pressing the mic icon on the right side. However, when I stop recording, the audio waveform doesn't show up below like in Matt's demo and the save icon doesn't become activated.

If I can get the demo up and running, the next problem I have is saving the wav file to the server instead of locally like in the demo. I've found several posts saying to use XMLHttpRequest(), however I can't really figure out how to connect those examples to recorderjs. Saving WAV File Recorded in Chrome to Server HTML5 & getUserMedia - Record Audio & Save to Web Server after Certain Time RecorderJS uploading recorded blob via AJAX

• javascript
• php
• html
• audio
• recorder.js

3 Answers 3

Using XMLHttpRequest to post wav or mp3 blobs to server is simple.

Just run this code wherever you have access to the blob element:

var xhr=new XMLHttpRequest();
xhr.onload=function(e) {
  if(this.readyState === 4) {
      console.log("Server returned: ",e.target.responseText);
  }
};
var fd=new FormData();
fd.append("audio_data",blob, "filename");
xhr.open("POST","upload.php",true);
xhr.send(fd);

I prefer XMLHttpRequest to $.ajax() because it does not require jQuery.

Server-side, upload.php is as simple as:

$input = $_FILES['audio_data']['tmp_name']; //temporary name that PHP gave to the uploaded file
$output = $_FILES['audio_data']['name'].".wav"; //letting the client control the filename is a rather bad idea

//move the file from temp name to local folder using $output name
move_uploaded_file($input, $output)

Source: https://blog.addpipe.com/using-recorder-js-to-capture-wav-audio-in-your-html5-web-site/ Live demo: https://addpipe.com/simple-recorderjs-demo/

I figured out one solution, but would still welcome others related to recorderjs. I used MP3RecorderJS at https://github.com/icatcher-at/MP3RecorderJS. The demo html works if you change the top of the html from src="js/jquery.min.js" and src="js/mp3recorder.js" to wherever they're located in your server. For me, it is src="jquery.min.js" and src="mp3recorder.js" I also had to do the same thing to the "mp3recorder.js" file: var RECORDER_WORKER_PATH = 'js/recorderWorker.js'; var ENCODER_WORKER_PATH = 'js/mp3Worker.js'; changed to var RECORDER_WORKER_PATH = 'recorderWorker.js'; var ENCODER_WORKER_PATH = 'mp3Worker.js';

The program is set up to record both mp3 and wav. I wanted wav, so I made a few more adjustments to the html file. At line 55 you'll find:

recorderObject.exportMP3(function(base64_mp3_data) {
      var url = 'data:audio/mp3;base64,' + base64_mp3_data;
      var au  = document.createElement('audio'); 

I changed that to:

recorderObject.exportWAV(function(base64_wav_data) {
      var url = 'data:audio/wav;base64,' + base64_wav_data;
      var au  = document.createElement('audio');   

The demo appends a new player each time you record. To prevent this, I deleted (commented out) the $recorder.append(au); part, made a new div to store the audio player, and then I clear that div each time, before the audio player is created. To upload to my server, I used a technique I learned from uploading images to a server save canvas image to server Basically, the "url" variable in line 56 was what I needed, but couldn't figure out how to put it in a universal variable to use by another function. So, I made a hidden div and made the contents of it equal to "url". I then referenced that div in a new function called "upload". I then used a php file called "uploadWav.php". I still have to figure out a way to activate and deactivate the upload button to prevent the user from uploading a blank file before recording, but that's another issue. Here's the final html and php that worked for me:

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>MP3 Recorder test</title>
  </head>
  <body id="index" onload="">

    <script type="text/javascript" src="jquery.min.js"></script>
    <script type="text/javascript" src="mp3recorder.js"></script>
    <script type="text/javascript">
    var audio_context;

    function __log(e, data) {
      log.innerHTML += "\n" + e + " " + (data || '');
    }

    $(function() {

      try {
    // webkit shim
    window.AudioContext = window.AudioContext || window.webkitAudioContext;
    navigator.getUserMedia = ( navigator.getUserMedia ||
                     navigator.webkitGetUserMedia ||
                     navigator.mozGetUserMedia ||
                     navigator.msGetUserMedia);
    window.URL = window.URL || window.webkitURL;

    var audio_context = new AudioContext;
    __log('Audio context set up.');
    __log('navigator.getUserMedia ' + (navigator.getUserMedia ? 'available.' : 'not  present!'));
  } catch (e) {
    alert('No web audio support in this browser!');
  }

  $('.recorder .start').on('click', function() {
    $this = $(this);
    $recorder = $this.parent();

    navigator.getUserMedia({audio: true}, function(stream) {
      var recorderObject = new MP3Recorder(audio_context, stream, { statusContainer:  $recorder.find('.status'), statusMethod: 'replace' });
      $recorder.data('recorderObject', recorderObject);

      recorderObject.start();
    }, function(e) { });
  });

  $('.recorder .stop').on('click', function() {
    $this = $(this);
    $recorder = $this.parent();

    recorderObject = $recorder.data('recorderObject');
    recorderObject.stop();

    recorderObject.exportWAV(function(base64_wav_data) {
      var url = 'data:audio/wav;base64,' + base64_wav_data;
      var au  = document.createElement('audio');

      document.getElementById("playerContainer").innerHTML = "";
      //console.log(url)

      var duc = document.getElementById("dataUrlcontainer");
      duc.innerHTML = url;

      au.controls = true;
      au.src = url;
      //$recorder.append(au);
      $('#playerContainer').append(au);

      recorderObject.logStatus('');
    });

  });

  });
  </script>


 <script>
    function upload(){

    var dataURL = document.getElementById("dataUrlcontainer").innerHTML;

      $.ajax({
      type: "POST",
      url: "uploadWav.php",
      data: { 
          wavBase64: dataURL
       }
    }).done(function(o) {
      console.log('saved'); 

      });

    }    
  </script>


 <div class="recorder">
  Recorder 1
  <input type="button" class="start"  value="Record" />
  <input type="button" class="stop" value="Stop" />
  <pre class="status"></pre>
 </div>

 <div><button onclick="upload()">Upload</button></div>

 <div id="playerContainer"></div>

 <div id="dataUrlcontainer" hidden></div>

 <pre id="log"></pre>

 </body>
 </html>

and the "uploadWav.php" file:

<?php
// requires php5
define('UPLOAD_DIR', 'uploads/');
$img = $_POST['wavBase64'];
$img = str_replace('data:audio/wav;base64,', '', $img);
$img = str_replace(' ', '+', $img);
$data = base64_decode($img);
$file = UPLOAD_DIR . uniqid() . '.wav';
$success = file_put_contents($file, $data);
print $success ? $file : 'Unable to save the file.';
?> 

//**Server Side Code**
package myPack;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.codec.binary.Base64;

@WebServlet("/MyServlet")
@MultipartConfig
public class MyServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public MyServlet() {
        super();
    }

    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
    }

    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        try {
            String name = request.getParameter("fname");
            String url = request.getParameter("myUrl");
            url = url.replace("data:audio/wav;base64,", "");
            url = url.replace(" ", "+");
            byte[] bytes = url.getBytes();
            byte[] valueDecoded = Base64.decodeBase64(bytes);
            FileOutputStream os = new FileOutputStream(new File("D://" + name
                    + ".wav"));
            os.write(valueDecoded);
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

**Client Side Code**


<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8">
<title>MP3 Recorder test</title>
</head>
<body id="index" onload="">

    <script type="text/javascript" src="js/jquery.min.js"></script>
    <script type="text/javascript" src="js/recorder.js"></script>
    <script type="text/javascript">
    var audio_context;

    function __log(e, data) {
      log.innerHTML += "\n" + e + " " + (data || '');
    }

    $(function() {

      try {
        // webkit shim
        window.AudioContext = window.AudioContext || window.webkitAudioContext;
        navigator.getUserMedia = ( navigator.getUserMedia ||
                         navigator.webkitGetUserMedia ||
                         navigator.mozGetUserMedia ||
                         navigator.msGetUserMedia);
        window.URL = window.URL || window.webkitURL;

        var audio_context = new AudioContext;
        __log('Audio context set up.');
        __log('navigator.getUserMedia ' + (navigator.getUserMedia ? 'available.' : 'not present!'));
      } catch (e) {
        alert('No web audio support in this browser!');
      }

      $('.recorder .start').on('click', function() {
        $this = $(this);
        $recorder = $this.parent();

        navigator.getUserMedia({audio: true}, function(stream) {
          var recorderObject = new MP3Recorder(audio_context, stream, { statusContainer: $recorder.find('.status'), statusMethod: 'replace' });
          $recorder.data('recorderObject', recorderObject);

          recorderObject.start();
        }, function(e) { });
      });

      $('.recorder .stop').on('click', function() {
        $this = $(this);
        $recorder = $this.parent();

        recorderObject = $recorder.data('recorderObject');
        recorderObject.stop();

        recorderObject.exportWAV(function(base64_wav_data) {
            var url = 'data:audio/wav;base64,' + base64_wav_data;
            var au  = document.createElement('audio'); 
            document.getElementById("playerContainer").innerHTML = "";
            //console.log(url)

            var duc = document.getElementById("dataUrlcontainer");
            duc.innerHTML = url;

            au.controls = true;
            au.src = url;
            //$recorder.append(au);
            $('#playerContainer').append(au);

            var fd = new FormData();
            fd.append('fname', 'test.wav');
            fd.append('myUrl', duc.innerHTML);
         $.ajax({
              type: "POST",
              url: "/audioPart2/MyServlet",
              data: fd,
              processData: false,
              contentType: false
            });
          recorderObject.logStatus('');
        });

      });

    });
    </script>

    <div class="recorder">
        Recorder 1 <input type="button" class="start" value="Record" /> <input
            type="button" class="stop" value="Stop" />
        <div id="playerContainer"></div>
        <div id="dataUrlcontainer" hidden></div>
        <pre class="status"></pre>
    </div>

<!--    <div class="recorder"> -->
<!--        Recorder 2 <input type="button" class="start" value="Record" /> <input -->
<!--            type="button" class="stop" value="Stop" /> -->
<!--        <pre class="status"></pre> -->
<!--    </div> -->

    <pre id="log"></pre>
</body>
</html>

**// Required JS 
1)jquery.min.js
2) recorder.js**


**recorder.js is below**
(function(window){

  var RECORDER_WORKER_PATH  = 'js/recorderWorker.js';
  var ENCODER_WORKER_PATH   = 'js/mp3Worker.js';


  var MP3Recorder = function(context, stream, cfg) {
    var config      = cfg || { statusContainer: null, statusMethod: 'append' }

    var bufferLen   = 4096;
    var recording   = false;

    this.source     = context.createMediaStreamSource(stream);
    this.node       = (context.createScriptProcessor || context.createJavaScriptNode).call(context, bufferLen, 1, 1);

    var recorderWorker  = new Worker(RECORDER_WORKER_PATH);
    var encoderWorker   = new Worker(ENCODER_WORKER_PATH);
    var exportCallback;


    // initialize the Recorder Worker
    recorderWorker.postMessage({ cmd: 'init', sampleRate: context.sampleRate });

    // the recording loop
    this.node.onaudioprocess = function(e) {
      if(!recording) return;
      recorderWorker.postMessage({ cmd: 'record', buffer: e.inputBuffer.getChannelData(0) });
    }


    this.start = function() {
      recording = true;
      this.logStatus('recording...');
    }
    this.stop = function() {
      recording = false;
      this.logStatus('stopping...');
    }
    this.destroy  = function() { recorderWorker.postMessage({ cmd: 'destroy' }); }

    this.logStatus = function(status) {
      if(config.statusContainer) {
        if(config.statusMethod == 'append') {
          config.statusContainer.text(config.statusContainer.text + "\n" + status);
        } else {
          config.statusContainer.text(status);
        }
      }
    }

    this.exportBlob = function(cb) {
      exportCallback = cb;
      if (!exportCallback) throw new Error('Callback not set');
      recorderWorker.postMessage({ cmd: 'exportBlob' });
    }

    this.exportWAV = function(cb) {
      // export the blob from the worker
      this.exportBlob(function(blob) {
        var fileReader = new FileReader();

        // read the blob as array buffer and convert it
        // to a base64 encoded WAV buffer
        fileReader.addEventListener("loadend", function() {
          var resultBuffer = new Uint8Array(this.result);
          cb(encode64(resultBuffer));
        });
        fileReader.readAsArrayBuffer(blob);
      });
    }

    this.exportMP3 = function(cb) {
      this.logStatus('converting...');

      // export the blob from the worker
      this.exportBlob(function(blob) {
        var fileReader = new FileReader();

        fileReader.addEventListener("loadend", function() {
          var wavBuffer = new Uint8Array(this.result);
          var wavData = parseWav(wavBuffer);

          encoderWorker.addEventListener('message', function(e) {
            if (e.data.cmd == 'data') {
              cb(encode64(e.data.buffer));
            }
          });

          encoderWorker.postMessage({ cmd: 'init', config: { mode: 3, channels: 1, samplerate: wavData.sampleRate, bitrate: wavData.bitsPerSample } });
          encoderWorker.postMessage({ cmd: 'encode', buf: Uint8ArrayToFloat32Array(wavData.samples) });
          encoderWorker.postMessage({ cmd: 'finish' });
        });

        fileReader.readAsArrayBuffer(blob);
      });
    }




    // event listener for return values of the recorderWorker
    recorderWorker.addEventListener('message', function(e) {
      switch(e.data.from) {
        case 'exportBlob':
          exportCallback(e.data.blob);
          break;
      };
    });


    // HELPER FUNCTIONS

    function encode64(buffer) {
        var binary  = '';
      var bytes   = new Uint8Array(buffer);
        var len     = bytes.byteLength;

        for(var i = 0; i < len; i++) {
            binary += String.fromCharCode(bytes[i]);
        }
        return window.btoa(binary);
    }

    function parseWav(wav) {
        function readInt(i, bytes) {
            var ret = 0, shft = 0;

            while(bytes) {
                ret += wav[i] << shft; shft += 8;
                i++; bytes--;
            }
            return ret;
        }
        if(readInt(20, 2) != 1) throw 'Invalid compression code, not PCM';
        if(readInt(22, 2) != 1) throw 'Invalid number of channels, not 1';

        return { sampleRate: readInt(24, 4), bitsPerSample: readInt(34, 2), samples: wav.subarray(44) };
    }

    function Uint8ArrayToFloat32Array(u8a){
        var f32Buffer = new Float32Array(u8a.length);
        for (var i = 0; i < u8a.length; i++) {
            var value = u8a[i<<1] + (u8a[(i<<1)+1]<<8);
            if (value >= 0x8000) value |= ~0x7FFF;
            f32Buffer[i] = value / 0x8000;
        }
        return f32Buffer;
    }


    this.source.connect(this.node);
    this.node.connect(context.destination);    // this should not be necessary
  }

  window.MP3Recorder = MP3Recorder;

})(window);