const myScript = document.querySelector("script");

const myPre = document.querySelector("pre");

const playButton = document.querySelector("button");

// Create AudioContext and buffer source

let audioCtx;

async function init() {

audioCtx = new AudioContext();

const source = audioCtx.createBufferSource();

// Create a ScriptProcessorNode with a bufferSize of 4096 and a single input and output channel

const scriptNode = audioCtx.createScriptProcessor(4096, 1, 1);

// Load in an audio track using fetch() and decodeAudioData()

try {

const response = await fetch("viper.ogg");

const arrayBuffer = await response.arrayBuffer();

source.buffer = await audioCtx.decodeAudioData(arrayBuffer);

} catch (err) {

console.error(

`Unable to fetch the audio file: ${name} Error: ${err.message}`

);

}

// Give the node a function to process audio events

scriptNode.addEventListener("audioprocess", (audioProcessingEvent) => {

// The input buffer is the song we loaded earlier

let inputBuffer = audioProcessingEvent.inputBuffer;

// The output buffer contains the samples that will be modified and played

let outputBuffer = audioProcessingEvent.outputBuffer;

// Loop through the output channels (in this case there is only one)

for (let channel = 0; channel < outputBuffer.numberOfChannels; channel++) {

let inputData = inputBuffer.getChannelData(channel);

let outputData = outputBuffer.getChannelData(channel);

// Loop through the 4096 samples

for (let sample = 0; sample < inputBuffer.length; sample++) {

// make output equal to the same as the input

outputData[sample] = inputData[sample];

// add noise to each output sample

outputData[sample] += (Math.random() * 2 - 1) * 0.1;

}

}

});

source.connect(scriptNode);

scriptNode.connect(audioCtx.destination);

source.start();

// When the buffer source stops playing, disconnect everything

source.addEventListener("ended", () => {

source.disconnect(scriptNode);

scriptNode.disconnect(audioCtx.destination);

});

}

// wire up play button

playButton.addEventListener("click", () => {

if (!audioCtx) {

init();

}

});