JavaScript Navigator mediaDevices Property

const lines = [
  "secure: " + window.isSecureContext,
  "mediaDevices: " + Boolean(navigator.mediaDevices)
];

if (!window.isSecureContext) {
  lines.push("Serve over HTTPS (or localhost) to use mediaDevices");
} else if (!navigator.mediaDevices) {
  lines.push("Secure, but MediaDevices API not exposed");
} else {
  lines.push("Ready for getUserMedia / enumerateDevices");
}

console.log(lines.join("\n"));

if (!navigator.mediaDevices) {
  console.log("MediaDevices API missing");
} else {
  navigator.mediaDevices.enumerateDevices().then((devices) => {
    console.log("count: " + devices.length);
    devices.slice(0, 8).forEach((d) => {
      console.log(
        d.kind +
          " | " +
          (d.label || "(no label yet)") +
          " | " +
          String(d.deviceId).slice(0, 8) +
          "…"
      );
    });
  });
}

async function startPreview() {
  if (!navigator.mediaDevices) {
    return "MediaDevices API not available.";
  }
  const stream = await navigator.mediaDevices.getUserMedia({
    video: true,
    audio: true
  });
  const tracks = stream.getTracks().map((t) => {
    return t.kind + ":" + (t.label || "(track)");
  });
  stream.getTracks().forEach((t) => t.stop());
  return "got stream → " + tracks.join(", ");
}

startPreview().then(console.log).catch((err) => {
  console.log((err.name || "Error") + ": " + (err.message || err));
});

if (!navigator.mediaDevices) {
  console.log("MediaDevices API missing");
} else {
  function refresh(note) {
    navigator.mediaDevices.enumerateDevices().then((devices) => {
      console.log(note);
      console.log("device count: " + devices.length);
    });
  }

  navigator.mediaDevices.addEventListener("devicechange", () => {
    refresh("devicechange — re-ran enumerateDevices()");
  });

  refresh("Listening for devicechange…");
}

function mediaDevicesStatus() {
  const md = navigator.mediaDevices;
  return {
    secure: window.isSecureContext,
    available: Boolean(md),
    getUserMedia: Boolean(md && md.getUserMedia),
    enumerateDevices: Boolean(md && md.enumerateDevices),
    getDisplayMedia: Boolean(md && md.getDisplayMedia)
  };
}

console.log(JSON.stringify(mediaDevicesStatus(), null, 2));