Ytukyg

I have used the following code which is identical to the following post's answer Is it possible to mix multiple audio files on top of each other preferably with javascript
But I want to download the audio blob as mp3 (not in mpeg or ogg format)without recording it by MediaRecorder which gets a stream because everytime I need to wait till the newly mixed audio file gets finished its playing. Also its not containing the whole mixed audio in blob, just only the first 48 second everytime its get downloadedI will be really grateful for the solution. Here is the current code:

function downloadMixedAudio() {

console.log(sources);

sources = [...new Set(sources)];

var description = "custom-mixed-audio";

var context;

var recorder;

var duration = Math.round(wavesurfer.getDuration() * 1000);

var chunks = ;

var audio = new AudioContext();

var mixedAudio = audio.createMediaStreamDestination();

var player = new Audio();

player.controls = "controls";



function get(src) {

return fetch(src).then(function(response) {

  return response.arrayBuffer();

});

}



function stopMix(duration, ...media) {

setTimeout(

  function(media) {

    media.forEach(function(node) {

      node.stop();

    });

  },

  duration,

  media

);

}



Promise.all(sources.map(get))

.then(function(data) {

  var len = Math.max.apply(

    Math,

    data.map(function(buffer) {

      return buffer.byteLength;

    })

  );

  context = new OfflineAudioContext(2, len, 44100);

  return Promise.all(

    data.map(function(buffer) {

      return audio.decodeAudioData(buffer).then(function(bufferSource) {

        var source = context.createBufferSource();

        source.buffer = bufferSource;

        source.connect(context.destination);

        return source.start();

      });

    })

  )

    .then(function() {

      return context.startRendering();

    })

    .then(function(renderedBuffer) {

      return new Promise(function(resolve) {

        var mix = audio.createBufferSource();

        mix.buffer = renderedBuffer;

        mix.connect(audio.destination);

        mix.connect(mixedAudio);

        recorder = new MediaRecorder(mixedAudio.stream);

        recorder.start(0);

        mix.start(0);

        // stop playback and recorder in 60 seconds

        stopMix(duration, mix, recorder);



        recorder.ondataavailable = function(event) {

          chunks.push(event.data);

        };



        recorder.onstop = function(event) {

          var blob = new Blob(chunks, {

            type: "audio/mpeg; codecs=opus"

          });

          console.log("recording complete");

          resolve(blob);

        };

      });

    })

    .then(function(blob) {

      console.log(blob);

      var audioURL = window.URL.createObjectURL(blob);

      document.getElementById("download-mixed").href = audioURL;

      document.getElementById("download-mixed").target = "_blank";

      document.getElementById("download-mixed").download =

        description + "." + blob.type.replace(/.+/|;.+/g, "");

      document.getElementById("download-mixed").style.display = "block";

    });

})

.catch(function(e) {

  console.log(e);

});

}

Please help me as I am stucked for days, need to complete the feature. Also I am a just a javascript beginner and new in posting questions too!
Apologies for mistakes and thanks in advance! Will be really grateful!