I am using wavesurfer to map an audio, however I need to build a VuMeter.
I used this implementation and everything works well except for the fact that on audioprocess only runs once.
function playSound(arraybuffer, vuMeterInput, audioSource, playBtn, pauseBtn, volumeController, waveFormID, startAt = 0, sourceNode = undefined) {
var context = new AudioContext();
var wavesurfer = WaveSurfer.create({
container: waveFormID,
waveColor: '#E0E0E0',
progressColor: '#64C2EB',
barWidth: 3,
height: 20,
audioContext: context
});
wavesurfer.load(audioSource.src);
console.log(wavesurfer.backend);
var source = wavesurfer.backend.ac.createBufferSource();
wavesurfer.backend.source = source;
var gainNode = wavesurfer.backend.ac.createGain();
wavesurfer.backend.ac.decodeAudioData(arraybuffer, function (buffer) {
wavesurfer.backend.source.buffer = buffer;
});
wavesurfer.loadDecodedBuffer();
wavesurfer.backend.analyser.smoothingTimeConstant = 0.3;
wavesurfer.backend.analyser.fftSize = 1024;
wavesurfer.backend.scriptNode.bufferSize = 4096;
wavesurfer.backend.scriptNode.numberOfInputs = 1;
wavesurfer.backend.scriptNode.numberOfOutputs = 1;
function MapVumeter(){
var array = new Uint8Array(wavesurfer.backend.analyser.frequencyBinCount);
valval = wavesurfer.backend.analyser.getByteFrequencyData(array);
console.log(valval);
console.log(Math.average(array));
vuMeterInput.mono.setAttribute("data-val", Math.average(array));
}
wavesurfer.backend.scriptNode.onaudioprocess = MapVumeter;
wavesurfer.backend.source.onended = function() {
$(playBtn).attr('hidden',false);
$(pauseBtn).attr('hidden',true);
vuMeterInput.mono.setAttribute("data-val", 0);
}
var is_paused = false;
$(playBtn).on('click', function(){
$(playBtn).attr('hidden',true);
$(pauseBtn).attr('hidden',false);
wavesurfer.play();
if(is_paused == true){
console.log("called the function again after pause");
}
});
$(pauseBtn).on('click', function(){
$(playBtn).attr('hidden',false);
$(pauseBtn).attr('hidden',true);
wavesurfer.pause();
vuMeterInput.mono.setAttribute("data-val", 0);
});
I am not sure why this works if I use an AudioContext, Analyser and gainNode outside of WaveSurfer but within wavesurfer it's only running once with a value of 0 for the val of
Math.average(array);
wavesurfer.js is using that
ScriptProcessorNode
as well. It will probably overwrite the event handler that you assign toonaudioprocess
.https://github.com/katspaugh/wavesurfer.js/blob/master/src/webaudio.js#L247
You could try registering your event handler with
addEventListener()
.