Key rotation

Key rotation for live streams is where a live stream encryption key changes periodically, and a new key needs to be fetched. No additional APIs are required for this feature, although there may be a slight pause in playback when key rotation occurs.

There may be a slight pause in playback when key rotation occurs. Depending on the licence server used, the default OTVHttpMediaDrmCallback class may not be able to handle key-rotation request if, for example, a new token is required for each key request. In that case, a bespoke class implementing OTVMediaDrmCallback may be needed instead. See the supplied example code (customised-encrypted-playback) for an example with a dedicated OTVCustomisedMediaDrmCallbackclass.

Key rotation and Temporal Licence Pre-delivery

To reduce key request calls to the licence server when playing a stream with key-rotation, the licence server may send back more than one key - the key for the next session, and more keys for the sessions following. SDK5 caches these additional keys and when a new key is required, the player checks if the key is already cached before submitting a request to the licence server. There is no additional API for this feature.

Storing pre-delivered keys is not supported for API levels below 23 (Marshmallow).