Se puede acceder a la cámara y el micrófono del usuario en la plataforma web con la API de Media Capture y Streams. El método getUserMedia() le solicita al usuario que acceda a una cámara o un micrófono para capturar como una transmisión multimedia. Luego, esta transmisión se puede procesar en un subproceso de Web Audio independiente con un AudioWorklet, que proporciona un procesamiento de audio de latencia muy baja.
En el siguiente ejemplo, se muestra cómo puedes procesar audio proveniente del micrófono del usuario de manera eficaz.
let stream;
startMicrophoneButton.addEventListener("click", async () => {
// Prompt the user to use their microphone.
stream = await navigator.mediaDevices.getUserMedia({
audio: true,
});
const context = new AudioContext();
const source = context.createMediaStreamSource(stream);
// Load and execute the module script.
await context.audioWorklet.addModule("processor.js");
// Create an AudioWorkletNode. The name of the processor is the
// one passed to registerProcessor() in the module script.
const processor = new AudioWorkletNode(context, "processor");
source.connect(processor).connect(context.destination);
log("Your microphone audio is being used.");
});
stopMicrophoneButton.addEventListener("click", () => {
// Stop the stream.
stream.getTracks().forEach(track => track.stop());
log("Your microphone audio is not used anymore.");
});
// processor.js
// This file is evaluated in the audio rendering thread
// upon context.audioWorklet.addModule() call.
class Processor extends AudioWorkletProcessor {
process([input], [output]) {
// Copy inputs to outputs.
output[0].set(input[0]);
return true;
}
}
registerProcessor("processor", Processor);
Navegadores compatibles
MediaDevices.getUserMedia()
Audio web
AudioWorklet
Lecturas adicionales
- Especificación de transmisiones y capturas de contenido multimedia de W3C
- Especificaciones de audio web de W3C
- Ingresa AudioWorklet
Demostración
HTML
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<link
rel="icon"
href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🎙️</text></svg>"
/>
<title>How to process audio from the user's microphone</title>
</head>
<body>
<h1>How to process audio from the user's microphone</h1>
<button id="startMicrophoneButton">Start using microphone</button>
<button id="stopMicrophoneButton" disabled>Stop using microphone</button>
<pre id="logs"></pre>
</body>
</html>CSS
:root {
color-scheme: dark light;
}
html {
box-sizing: border-box;
}
*,
*:before,
*:after {
box-sizing: inherit;
}
body {
margin: 1rem;
font-family: system-ui, sans-serif;
}
button {
display: block;
margin-bottom: 4px;
}
pre {
color: red;
white-space: pre-line;
}
JS
const startMicrophoneButton = document.querySelector('#startMicrophoneButton');
const stopMicrophoneButton = document.querySelector('#stopMicrophoneButton');
let stream;
startMicrophoneButton.addEventListener("click", async () => {
// Prompt the user to use their microphone.
stream = await navigator.mediaDevices.getUserMedia({
audio: true,
});
const context = new AudioContext();
const source = context.createMediaStreamSource(stream);
// Load and execute the module script.
await context.audioWorklet.addModule("processor.js");
// Create an AudioWorkletNode. The name of the processor is the
// one passed to registerProcessor() in the module script.
const processor = new AudioWorkletNode(context, "processor");
source.connect(processor).connect(context.destination);
stopMicrophoneButton.disabled = false;
log("Your microphone audio is being used.");
});
stopMicrophoneButton.addEventListener("click", () => {
// Stop the stream.
stream.getTracks().forEach(track => track.stop());
log("Your microphone audio is not used anymore.");
});