Audio chunk decoding over WebSocket

Question

I use WebSocket to stream audio file's chunks. I defined a handler for the Socket.onmessage event and I defined an AudioContext. The problem is I lose chunks when I decode audio data. Here is my handler:

var socket = new WebSocket('ws://127.0.0.1:8080');
socket.binaryType = 'arraybuffer';
socket.onmessage = function(msg) {
  console.log('received'); // printed 29 times
  audioctx.decodeAudioData(msg.data, function(buffer) {
    console.log('decoded'); // printed 1 time
  });
};

I think it's linked to the asynchronism of the callback function but I don't know how to fix it.

score 2 · Accepted Answer · answered Mar 12 '15 at 00:09

decodeAudioData does not support block-level data; it wants an entire file (MP3 header, e.g., not just a chunk begin). It's not that it's async; it's that (I believe) it's failing to decode, because it only decodes the first block and all subsequent blocks fail.

Until there's a better decoding api with progressive support, you'll have to pull in a JS decoding library.

Audio chunk decoding over WebSocket

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