MediaKeys

Secure context

The MediaKeys interface of Encrypted Media Extensions API represents a set of keys that an associated HTMLMediaElement can use for decryption of media data during playback.

Instance properties

None.

Instance methods

• createSession()
  • : Returns a new MediaKeySession object, which represents a context for message exchange with a content decryption module (CDM).
• getStatusForPolicy()
  • : Returns a Promise that resolves to a status string indicating whether the CDM would allow the presentation of encrypted media data using the keys, based on specified policy requirements.
• setServerCertificate()
  • : Returns a Promise to a server certificate to be used to encrypt messages to the license server.

Examples

Check if keys are usable with HDCP restriction

This example shows how getStatusForPolicy() can be used to check if keys can decrypt a particular video format in a setup that has a minimum HDCP version of 2.2. For more information, see the MediaKeys: getStatusForPolicy() method documentation.

HTML

<pre id="log"></pre>

#log {
  height: 100px;
  overflow: scroll;
  padding: 0.5rem;
  border: 1px solid black;
}

JavaScript

const logElement = document.querySelector("#log");
function log(text) {
  logElement.innerText = `${logElement.innerText}${text}\n`;
  logElement.scrollTop = logElement.scrollHeight;
}

const config = [
  {
    videoCapabilities: [
      {
        contentType: 'video/mp4; codecs="avc1.640028"',
        encryptionScheme: "cenc",
        robustness: "SW_SECURE_DECODE", // Widevine L3
      },
    ],
  },
];

getMediaStatus(config);

async function getMediaStatus(config) {
  try {
    const mediaKeySystemAccess = await navigator.requestMediaKeySystemAccess(
      "com.widevine.alpha",
      config,
    );
    const mediaKeys = await mediaKeySystemAccess.createMediaKeys();
    const mediaStatus = await mediaKeys.getStatusForPolicy({
      minHdcpVersion: "2.2",
    });
    log(mediaStatus);

    // Get the content or fallback to an alternative if the
    // keys are not usable
    if (mediaStatus === "usable") {
      console.log("HDCP 2.2 can be enforced.");
      // Fetch the high resolution protected content
    } else {
      log("HDCP 2.2 cannot be enforced");
      // Fallback other content, get license, etc.
    }
  } catch (error) {
    log(error);
  }
}

Results

Specifications

Browser compatibility