Graphics Reference
In-Depth Information
effectively with each other. In some cases, some freedom that is provided in
the video coding standard may be constrained in other ways, such as constraints
imposed by other specifications that govern usage in particular application environ-
ments.
Another key element of a good international standard is the quality of its
specification documentation and the availability of additional material to help
implementers to use the design and to use it well. In the case of HEVC (and AVC
and some other international standards before those), this includes the following:
The text specification itself
: in the case of HEVC version 1, the document [
3
]
is about 300 pages of carefully-written (although dense and not necessarily easy
to read) detailed specification text that very clearly describes all aspects of the
standard.
Reference software source code
: a collaboratively developed software codebase
that can provide a valuable example of how to use the standard format (for
both encoding and decoding) and help clarify any ambiguities or difficulties of
interpreting the specification document.
Conformance data test set
: a suite of tests to be performed to check implemen-
tations for proper conformance to the standard.
Other standards designed to work with the technology
: this includes many
other industry specifications and formal standards that have been developed,
maintained, and enhanced within the same broad industry community that
developed the video coding specification itself—e.g., data multiplexing designs,
systems signaling and negotiation mechanisms, storage formats, dynamic deliv-
ery protocols, etc.
Many supplemental publications in industry and academic research
literature
: a diverse source of tutorial information, commentary, and exploration
of the capabilities, uses, limitations, and possibilities for further enhancement
of the design. This topic, of course, is intended to become a key part of this
phenomenon.
The syntax of the HEVC standard has been carefully designed to enable
flexibility in how it is used. Thus, the syntax contains features that give it a unified
syntax architecture that can be used in many different system environments and
can provide customized tradeoffs between compression and other aspects such as
robustness to data losses. Moreover, the high-level syntax framework of the standard
is highly extensible and provides flexible mechanisms for conveying (standard or
non-standard) supplemental enhancement information along with the coded video
pictures.
Maintenance of the standard specifications (and the development of further
enhancement extensions in a harmonized manner) is another significant part of the
phenomenon of standardization best practices. In the case of HEVC, the standard,
and the associated related standards, have been collaboratively developed by the
most well-established committees in the area and with a commitment to follow
through on the developments represented by the formal specifications.
