for starters createJavaScriptNode is deprecated, instead use createScriptProcessor this works :
var audio_context;
var BUFF_SIZE = 512;
var microphone_data = {};
try {
window.AudioContext = window.AudioContext || window.webkitAudioContext;
audio_context = new AudioContext();
console.log("cool audio context established");
} catch (e) {
alert('Web Audio API is not supported by this browser and/or its current config\n');
}
function process_microphone_buffer(event) {
var microphone_buffer = event.inputBuffer.getChannelData(0);
console.log('microphone_buffer.length ', microphone_buffer.length);
}
function on_error(e) {
console.log(e);
}
function start_microphone() {
microphone_data.microphone_stream = audio_context.createMediaStreamSource(microphone_data.media_stream);
microphone_data.script_processor_node = audio_context.createScriptProcessor(BUFF_SIZE, 1, 1);
microphone_data.script_processor_node.onaudioprocess = process_microphone_buffer;
microphone_data.microphone_stream.connect(microphone_data.script_processor_node);
microphone_data.microphone_stream.connect(audio_context.destination);
console.log('OK microphone stream connected');
}
function record_microphone() { // call this from your UI ... say a button
if (! navigator.getUserMedia) {
navigator.getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
}
navigator.getUserMedia(
{audio: true},
function(stream) {
microphone_data.media_stream = stream;
start_microphone();
},
on_error
);
}
function stop_microphone() { // call this from ... say a button
microphone_data.microphone_stream.disconnect();
microphone_data.script_processor_node.disconnect();
microphone_data.media_stream.stop();
microphone_data.script_processor_node.onaudioprocess = null;
console.log('... microphone now stopped') ;
}
take care