General encryption options
^^^^^^^^^^^^^^^^^^^^^^^^^^

--protection_scheme <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 <seconds>

    Clear lead in seconds if encryption is enabled.
    Shaka Packager does not support partial encrypted segments, all the 
    segments including the partial segment overlapping with the initial 
    'clear_lead' seconds are not encrypted, with all the following segments 
    encrypted. If segment_duration is greater than 'clear_lead', then only the
    first segment is not encrypted.
    Default: 5

--protection_systems

    Protection systems to be generated. Supported protection systems include
    Widevine, PlayReady, FairPlay, Marlin, and
    CommonSystem (https://goo.gl/s8RIhr).