General encryption options ^^^^^^^^^^^^^^^^^^^^^^^^^^ --protection_scheme Specify a protection scheme, 'cenc' or 'cbc1' or pattern-based protection schemes 'cens' or 'cbcs'. --vp9_subsample_encryption, --novp9_subsample_encryption Enable / disable VP9 subsample encryption. Enabled by default. --clear_lead Clear lead in seconds if encryption is enabled. --additional_protection_systems Generate additional protection systems in addition to the native protection system provided by the key source. Supported protection systems include Widevine, PlayReady, and CommonSystem (https://goo.gl/s8RIhr).