This site is the registration authority for AC-4 EMDF payload identifiers
(“EMDF Payload IDs”) and AC-4 key identifiers
(“EMDF Key IDs”).
EMDF (Extensible Metadata Delivery Format) is an extensible structure for
metadata delivery defined in ETSI TS 103 190-1 Digital Audio Compression (AC-4)
Standard. This format is based on structuring metadata into payloads that are
compatible with the EMDF structure. Each payload is tagged with a specific
payload identifier (payload ID) to provide an unambiguous indication of the
type of data present in the payload. Interoperation of bitstreams containing
EMDF payloads relies on unique payload IDs to prevent conflicts.
EMDF protection data can be used to verify
the integrity of the EMDF substream and the payload data within the EMDF
substream. The EMDF key identifier (key ID) indicates the protection method
used.
As indicated in ETSI TS 103 190-1 payload IDs and
key IDs not assigned in ETSI TS 103 190-1, or sources specifically
referenced by ETSI TS 103 190-1, may be assigned a payload ID/key ID via the AC-4 EMDF registration
authority, represented by this site. On this site you may:
•find assignment of EMDF payload IDs and key IDs for payload types and protection methods that have
already been registered
•request an EMDF payload ID for a payload type or EMDF key ID for a protection scheme
•find information and sources of documentation for payload
IDs and key IDs that have been registered, when supplied by the registrant
There is no cost for using this service. Dolby Laboratories operates this for
the benefit of the standards community.