MediaKeysRequirement

MediaKeysRequirement: "required" | "optional" | "not-allowed"

required:

 When used in a call to requestMediaKeySystemAccess(),
     the returned object must support this feature.
  When returned by a MediaKeySystemAccess object,
 CDM instances created by the object may use this feature.

optional:

 When used in a call to requestMediaKeySystemAccess(),
     the returned object may support and use this feature.
 When returned by a MediaKeySystemAccess object,
     this value cannot and must not be present in such an object.

not-allowed:

 When used in a call to requestMediaKeySystemAccess(),
     the returned object must function without using this feature and must not use it at any time.
 When returned by a MediaKeySystemAccess object
     CDM instances created by the object must not use this feature.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysrequirement.

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Last updated: Oct 02, 2025