Engineering @huggingface 🤗. Data visualization enthusiast. Creative technologist. Open for collaborations.
volumeData = Generators.observe((change) => {
try {
const microphone = audioCtx.createMediaStreamSource(stream);
const node = new AudioWorkletNode(audioCtx, "audio-monitor", {
parameterData: {
clipLevel: clipLevel,
averaging: 0.9,
clipLag: 750
}
});
node.port.onmessage = (event) => {
change(event.data.volume);
};
invalidation.then(() => microphone.disconnect());
microphone.connect(node).connect(audioCtx.destination);
} catch (e) {
console.log(e);
}
})
scriptURL = {
const codeString = `
const QUANTUM_SIZE = 128;
class audioMonitor extends AudioWorkletProcessor {
constructor() {
super();
this._volume = 0;
this._updateIntervalInMS = 25;
this._nextUpdateFrame = this._updateIntervalInMS;
}
static get parameterDescriptors() {
return [{name: 'clipLevel', defaultValue: 0.98},
{name: 'averaging', defaultValue: 0.95},
{name: 'clipLag', defaultValue: 750}];
}
get intervalInFrames() {
return this._updateIntervalInMS / 1000 * sampleRate;
}
process(inputs, outputs, parameters) {
const clipLevel = parameters.clipLevel[0];
const averaging = parameters.averaging[0];
const clipLag = parameters.clipLag[0];
const input = inputs[0];
const volumes = input.map((channel, id) => {
const samples = channel;
let sum = 0;
let isClipping = false;
let lastClip = 0;
// Calculated the squared-sum.
for (let i = 0; i < samples.length; ++i){
if(Math.abs(samples[i]) >= clipLevel) {
isClipping = true;
lastClip = Date.now();
}
if((lastClip + clipLag) < Date.now()) isClipping = false;
sum += samples[i] * samples[i];
}
// Calculate the RMS level and update the volume.
const rms = Math.sqrt(sum / samples.length);
// Now smooth this out with the averaging factor applied
// to the previous sample - take the max here because we
// want "fast attack, slow release."
this._volume = Math.max(rms, this._volume * averaging);
return { value: this._volume, clipping: isClipping }
})
// Update and sync the volume property with the main thread.
this._nextUpdateFrame -= QUANTUM_SIZE;
if (this._nextUpdateFrame < 0) {
this._nextUpdateFrame += this.intervalInFrames;
this.port.postMessage({
volume: volumes
});
}
return true;
}
};
registerProcessor('audio-monitor', audioMonitor)`;
return URL.createObjectURL(
new Blob([codeString], { type: "text/javascript" })
);
}
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.