DASH-IF IOP 3.0 Compliance: Add default_KID and cenc:pssh in ContentProtection element.

[kqyang]

7.4.1.1. ContentProtection Descriptor for mp4protection Scheme

A ContentProtection Descriptor for the mp4 Protection Scheme is used to identify the default KID, as specified by the ‘tenc‘ box, using the @cenc:default_KID attribute defined in [26], section 11.1. The value of the attribute is the KID expressed in UUID string notation.

7.4.1.3. Protection System Specific Header Box cenc:pssh element in MPD

A ’pssh’ box is defined by each DRM system for use with their registered SystemID, and the same box can be stored in the MPD within a ContentProtection Descriptor for UUID scheme using an extension element in the “cenc:” namespace.

These fields are not required but good to have.

[kqyang]

Fixed.

For live with key rotation, default_KID is set to all zeros - which is what we have in TENC box. PSSH is not included in ContentProtection descriptor as PSSH is changing.