(() => {
  const format = { ext: "png", mime: "image/png", };
  const video = document.querySelector("video");
  const width = video.videoWidth;
  const height = video.videoHeight;
  const canvas = document.createElement("canvas");
  canvas.width = width;
  canvas.height = height;
  const ctx = canvas.getContext("2d");
  ctx.drawImage(video, 0, 0, width, height);
  const timestamp = (new Date()).toISOString()
    .replaceAll(/[t:]/gi, "-")
    .replaceAll(/\..*$/gi, "");
  canvas.toBlob((it) => {
    const url = URL.createObjectURL(it);
    const a = document.createElement("a");
    a.href = url;
    a.download = `screenshot-${timestamp}.${format.ext}`;
    a.click();
    URL.revokeObjectURL(url);
  }, format.mime, 1);
})();