IEEE Consumer Electronics Magazine - October 2015 - 88

Table 1. Stages in standards development.
Stages

Activities

Stage 0: Before the big
bang

Workshops, new work item
proposals, and call for evidence

Stage 1: Big bang

Call for proposals, test
model selection, and naming
of standards

Stage 2: Competition

Technology competition, core
experiments, and working draft

Table 2. The functionalities being discussed for
future video coding.
Functionality

Target

Compression efficiency

30-50% better than HEVC

Service bitrates

4-100 Mb/s

Wide color gamut and high
dynamic range

Ten or more bits per color
component

High frame rates (Hz)

60, 120, or more

Stage 3: Ballot

Committee draft and balloting

Picture formats

7,680 x 4,320 or higher

Stage 4: International
standard

Publication of standards

Complexity

Room for more complex
tools

So far, the major driving force of a new coding standard has
been a substantial improvement over the existing standards. It
is claimed by standard experts that HEVC is about four times
better than MPEG-2 and about two times better than MPEG-4
AVC/H.264. If there is a new coding standard, should it be
twice as good as HEVC? Is the supreme compression efficiency the only thing that matters? The encoding process of HEVC
is known to be more complex and time-consuming compared
to the existing codecs. Should the complexity be less important
than compression efficiency? Do we have other requirements
and markets for a new video coding? These are the big questions posed to the standard experts in MPEG after HEVC.

FROM REQUIREMENTS TO TECHNOLOGY STANDARD
If you are new to video coding standards, you might say,
"Hey, what is all the fuss? HEVC is not even fully in use
yet." It is helpful to know that video coding standards are
anticipatory standards, which means that the standard precedes the market. MPEG-2 was standardized before the
advent of the markets of digital TVs and set-top boxes. Since
the development of MPEG-2, MPEG with VCEG (from ITU)
has successfully developed a series of video coding standards
such as AVC/H.264 and HEVC/H.265. The markets also
adopted new standards for new applications such as IPTV
and ultrahigh-definition (UHD) TV.
Table 1 shows several stages that take place in developing a
standard. Seeds of new standardization may come out in various ways, such as technical workshops, new work item proposals, and calls for new evidence for a new standard. In this stage
(i.e., Stage 0), the requirements are collected and refined
through the aforementioned activities. The requirements are
necessary to define the functionalities of a new standard.
Therefore, how to define the requirements will dominate how
the resulting standard will be performed.
For example, one of the most apparent requirements of
HEVC is compression efficiency. HEVC was designed to be
30% better than its predecessor AVC in compression efficiency.
Now we often hear that HEVC is 50% better than AVC. However, compression efficiency is not the only requirement in video
coding, although it is one of the most important requirements.
88 IEEE Consumer Electronics Magazine

october 2015

Usually, new requirements are drawn by new markets, and
new markets are created by new technologies. Industries view
fifth-generation and beyond UHD as two driving forces for a new
video coding standard. Table 2 shows some requirements under
discussion for future video coding. These requirements are by no
means final yet, and it is likely that the requirements will be
refined and enhanced as the discussion in MPEG continues. However, the final requirements will not be surprising in the sense that
the requirements on the table are already challenging enough.

CHALLENGES AND EXPECTATIONS
Industries are believed to have prepared the next thing after
HEVC for quite some time. The question is whether the new
coding standard will meet the requirements as expected. The
year 2020 is taken as the expected delivery date for a new
standard to be finalized. One obvious expectation of a new
coding standard is that both the computational complexity of
encoding and decoding will be much higher than that of
HEVC. The computational complexity has been the major
sacrifice for achieving a better compression efficiency.
Ever since the analog TV was replaced by the digital TV, it
has become the norm for an average consumer to embrace a
new media device equipped with a new coding standard. JPEG
provides good compression quality over an original image with
about a 10:1 compression ratio. As the size of images is relatively small, the enhanced compression efficiency does not
provide a competitive edge to a new image codec. Considering
that an uncompressed 2-h movie of UHD resolution is about
4 TBs, compression efficiency will remain the major motivator
for a new video coding standard. Can the next coding standard
be twice as good as its predecessors? In 2020, we will know
the answer. Until then, it is time to enjoy HEVC.

ABOUT THE AUTHOR
Euee S. Jang (profjang@gmail.com) is currently a professor
at Hanyang University, Seoul, South Korea, and a visiting
scholar at Telecom SudParis, France. He has been actively
participating in MPEG standardization since 1996.

Table of Contents for the Digital Edition of IEEE Consumer Electronics Magazine - October 2015