20 行 JavaScript 的简单屏幕录像机

const button = document.createElement("button");
button.innerHTML = "capture";
document.body.append(button);
button.addEventListener("click", async () => {
  // TODO
});

const stream = await navigator.mediaDevices.getDisplayMedia();
const recoder = new MediaRecorder(stream);
recoder.start();

const [video] = stream.getVideoTracks();
video.addEventListener("ended", () => {
  recoder.stop();
});

recoder.addEventListener("dataavailable", (evt) => {
  const a = document.createElement("a");
  a.href = URL.createObjectURL(evt.data);
  a.download = "capture.webm";
  a.click();
});