eng TELE-audiovision 1307

FEATURE Ultra High Definition
Designed for
Ultra High Definition TV
Jacek pawlowski
Every 9-11 years we observe
a step forward in digital
video technology. Compare
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 picture
1.
Is it possible that the smart
guys working on digital video
standardization are influenced
by this natural phenomenon?
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 article.
The new standard is selfexplained
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 channel,
HD channel and a future
Ultra HD channel depending
on video compression method:
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 bigger
improvement than HD
■
had over SD (760p/1080i vs.
480i/576i).
As everybody can see, the
improvement in data compression
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 video
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 conclusion
was that the average bit
picture 1: David Hathaway, NASA Marshall Space Flight center (http://solarscience.msfc.nasa.gov)
128 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 07-08/2013 — www.TELE-audiovision.com
rate reduction for HEVC compared
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 resolutions
than today’s HDTV?
Yes, they have. One of the
most rigorous tests was carried
out by the researchers
from the Ecole Polytechnique
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 content:
Road Traffic, People On
the Street and Sintel2 (computer
animation). Eeach video
stream was compressed
with: MPEG-4 codec and
HVEC codec. The test result
was: HVEC significantly outperforms
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 inevitably
entail a lot of turmoil
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
Table 1: Comparing Standard Definition, High Definition and Ultra High Definition Characteristics