1. ■
126 127TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 07-08/2013 — www.TELE-audiovision.com www.TELE-audiovision.com — 07-08/2013 — TELE-audiovision International — 全球发行量最大的数字电视杂志
The New
HEVC/H.265
Standard
• reduced bandwidth by 50%
• can be used also for very small screens
• divides the video in 64x64 pixel blocks
• requires advanced processors in the
receiver
Picture from Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/File:Sunspot_TRACE.jpeg (Photo Credit: NASA/TRACE)
FEATURE Ultra High Definition

2. ■
■
■
128 129TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 07-08/2013 — www.TELE-audiovision.com www.TELE-audiovision.com — 07-08/2013 — TELE-audiovision International — 全球发行量最大的数字电视杂志
FEATURE Ultra High Definition
Designed for
Ultra High Definition TV
Jacek Pawlowski
rate reduction for HEVC com-
pared to H.264/MPEG-4 AVC
was 49.3%. So very, very
close to the initial target.
But what about UHD? Has
anybody tested the HEVC
performance for higher reso-
lutions than today’s HDTV?
Yes, they have. One of the
most rigorous tests was car-
ried out by the researchers
from the Ecole Polytech-
nique Federale de Lausanne
in Lausanne, Switzerland.
They used a large ultra high
resolution LCD monitor (56”
Sony Trimaster SRM-L560)
and prepared 3 different bit
streams with different con-
tent: Road Traffic, People On
the Street and Sintel2 (com-
puter animation). Eeach vid-
eo stream was compressed
with: MPEG-4 codec and
HVEC codec. The test result
was: HVEC significantly out-
performs MPEG-4. Moreover,
it is possible to achieve a
50-75% reduction in bit rate
if HVEC is used instead of
MPEG-4.
New standard will inevi-
tably entail a lot of turmoil
not only in the digital TV in-
dustry. It will also affect the
Internet world. Most likely
it will marginalize the VP8
codec that Google realized
for royalty-free use. It will
also affect mobile devices.
Despite the fact that HVEC
is specified to resolutions
as high as 8,192 × 4,320
pixels, it has a lot of much
lower modes of operation
(the professionals call them
profiles). For example, the
lowest Profile 1 is specified
for a resolution of 128×96
@ 33.7 frames per second
and just 128 kbps bit rate.
The profiles go up to Profile
6.2 which is suitable for the
highest resolutions and the
highest bit rates. Once HVEC
is widely accepted, we will
find it everywhere: from very
simple cheap devices with
very small screens up to the
largest flat screen monitors
and TVs. Should HEVC be
useful only for very high res-
olutions, one could be skepti-
TELE-audiovision's editor
Jacek Pawlowski enjoys the help
of his personal assistant while
working on this report.
Picture 1: David Hathaway, NASA Marshall Space Flight Center (http://solarscience.msfc.nasa.gov)
Table 1: Comparing Standard Definition, High Definition and Ultra High Definition Characteristics
Every 9-11 years we ob-
serve a step forward in digi-
tal video technology. Com-
pare the dates of the main
standard publications:
- 1992: VCD, CDi
- 1994: MPEG-2 (H.262)
and DVD-Video
- 2004: MPEG-4 (H.264),
Blu-ray Disc, Internet
streaming, mobile video
- 2013: HEVC (H.265) - the
expected new standard for
ultra high definition video
The interesting thing is
that this corresponds more
or less to the 11 years long
solar cycle. Every 11 years,
the number of sunspots
reach a maximum - see pic-
ture 1.
Is it possible that the smart
guys working on digital video
standardization are influ-
enced by this natural phe-
nomenon? Perhaps a high
number of sunspots turns
them up so much that they
simply have to reduce the
tension and publish a new
standard? We will come back
to that at the end of this ar-
ticle.
The new standard is self-
explained by its name – HEVC
means High Efficiency Video
Coding. HVEC is claimed to
be about 50% more efficient
than MPEG-4/H.264. Let’s
compare what bit rates are
needed for today’s SD chan-
nel, HD channel and a future
Ultra HD channel depending
on video compression meth-
od: MPEG-2, MPEG-4 and
HEVC. We put the figures in
table 1.
Please note that by a UHD
channel we mean a video
resolution of 3,840 x 2,160
pixels in a progressive mode
(2160p). So, it is even a big-
ger improvement than HD
had over SD (760p/1080i vs.
480i/576i).
As everybody can see, the
improvement in data com-
pression is tremendous. In
fact, when work on HEVC
started this was the main
objective: to achieve about
50% improvement in coding
efficiency without sacrificing
video quality perceived by
humans. And here we come
to a very vital question: does
HEVC really guarantee a vid-
eo quality comparable with
today’s HD?
The first tests have been
already carried out. Most of
them dealt with HD material
and indeed proved that HVEC
did pretty well in comparison
to MPEG-4. The final conclu-
sion was that the average bit
cal about its quick implemen-
tation in real world products.
But because it offers a 50%
bit rate reduction which
means also a 50% bandwidth
reduction, one can be certain
it will not be long when most
of the new equipment will be
HEVC compatible.
How was it possible that
HVEC is so much better than
MPEG-4 which up to now we
all used to regard as state of
the art technology? And why
did the scientists and engi-
neers not invent HVEC ten
years ago when they came
up with MPEG-4?
The answer is: 10 years
ago the available processors
and memories were too weak
and too small to make this
technology feasible. To re-
duce the required bit rate by
half, an HVEC receiver has to
be equipped with a fast mul-
ti-core processor and large
and fast memories. An HEVC
decoder has to process the
signal in a number of tasks
in parallel. This is possible
because in the HEVC con-
cept, the video frames are
divided into multiple tiles and
each tile is then processed
in parallel. Moreover, HVEC
breaks video frames not into
16x16 pixel blocks like it was
in H.264, but into blocks of
64x64 pixels. One can easily
imagine that the power of the
receiver processor must be
correspondingly greater to
process bigger blocks.
We said that HEVC is pos-
sible today due to great ad-
vances in technology. Let’s
compare what was avail-
able at the time digital video
standards were and will be
published:
- 1992: IC technology > 1
micron, memory >50$/MB,
processor 500 MHz
- 2003: IC technology < 0.1
micron, memory <50$/GB,
processor ~3 GHz single-core
- 2013: IC technology 14
nm, memory <5$/GB, pro-
cessor ~3 GHz multi-core
So, were the authors of
digital video standards in-
fluenced by the solar cycle
or rather by advances in
technology? I think the an-
swer is now clear. And is the
HEVC/H.265 the end of the
road or they will invent and
standardize yet another more
efficient compression stand-
ard in the future? Ask me in
11 years.
MPEG-2 (H.262) MPEG-4 (H.264) HVEC (H.265)
SD (480i/576i) 2.5-3.5 Mbps 1.5-2.5 Mbps 0.8-1.5 Mbps
HD (1080i) 12-18 Mbps 6-9 Mbps 3-4.5 Mbps
UHD (2160p) 12-18 Mbps 6-9 Mbps