context) {
                                    return;
                                }
                                context.decodeAudioData(buf.buffer, function(audioBuffer) {
                                    var offlineContext = new OfflineAudioContext(audioBuffer.numberOfChannels, audioBuffer.length, audioBuffer.sampleRate);
                                    var source = offlineContext.createBufferSource();
                                    source.buffer = audioBuffer;
                        