already buy several models of 4KTVs
(“4K” in this case stands for a resolution
of 3840x2160 pixels, more accurately described
as Quad HD or 2160p), starting
with super-cheap models from Chinese
brands like TCL and continuing with higher-
priced versions from Samsung, Sony,
Sharp, LG, and Panasonic.
However, as you might have guessed, the UHDTV
delivery system is far from complete, and
there are already some significant technical
obstacles to overcome: The first is the
new HDMI 2.0 standard, which is barely
fast enough to deliver Quad HD content
at 60 Hz, using 8-bit color. The consensus
of presenters, panelists, and attendees at
the SMPTE Technology Conference 4K session recently was that 8-bit color is
inadequate for UHDTV, and that 10-bit and
preferably 12-bit color should be used in a
full 4:4:4 (RGB) delivery format.
That’s not difficult to do if the source
frame rate is 24 Hz, but it will be impossible
with fast frame rates over HDMI 2.0.
And higher frame rates, plus high dynamic
range and deep color, are seen as the real
attractions to 4K, according to SMPTE presenters
and panelists. So, before UHDTV is
even out of the gate, there is already a major
You’ll also discover a growing belief
among video professionals that it’s finally
time to ditch the “backwards-compatible”
obsession that has dogged our television
systems since NTSC color was standardized
60 years ago.
For UHDTV, this would mean moving
exclusively to RGB color, dropping fractional
frame rates, and burying interlaced
scanning for good as the new UHDTV
ecosystem is developed. This sounds like
a great idea on paper, but it raises plenty
of questions with respect to signal format
Right now, we have a hodge-podge of
broadcast and video formats coming into
our 2K-resolution LCD and plasma TVs, including
480i, 480p, 720p, 1080i, and 1080p
delivered through MPEG4 H.264 encoding.
How will each of those look on a UHDTV?
Upscaling 1080p content appears to be
the easiest task, as horizontal and vertical
resolution are both doubled using straight
pixel interpolation and no de-interlacing
is required. Most 1080p content originates
from optical disc or streaming sources and
comes with slow frame rates (read: movies).
But things aren’t quite so simple with
high frame rate sources, such as live 60Hz
programming. Presently, all of that originates
as either a 720p/60 broadcast or a 1080i/30
broadcast. Jumping from 720p to 2160p requires
tripling the number of pixels in both
axes, plus performing motion interpolation
for the two additional pixels. 1080i adds the
burden of de-interlacing to the process.
And how does upconverted 720p and
1080i programming look? Not as bad as
you might think, but it’s definitely a step
down from native 4:4:4 2160p content, as
demonstrated at the SMPTE event by several
manufacturers of video processors.
Think of the difference between 480i composite
video and 1080p 4:2:2, and you get
|The writer leads a session on 4K delivery at SMPTE last month.
And as we all know, there is still a lot
of 480i source material out there, particularly
on secondary minor channels like
“Antenna TV” and “This TV.” These channels
specialize in “good old days” programming
from the 50’s, 60’s, 70’s, and even the 80’s;
all formatted to 4:3 and all using interlaced
black-and-white and color formats.
How big is the jump from 480i to
2160p? Assuming a clean de-interlacing
job, the pixels need to be interpolated 4.5
times. (And they’re in the wrong aspect ratio
to begin with.) Add in the fact that you
really want to sit closer to a UHDTV screen
to get the immersive viewing experience,
and you’ll quickly realize that NTSC should
be buried for good.
While Blu-ray advocates work on a new standard for
2160p/Quad HD authoring, there’s a new
source for 4K content delivery: Streaming.
Amazing as it may seem, Netflix is already
testing 4K movie delivery and plans to
roll it out next year for premium subscribers.
Netflix CEO Reid Hastings said a few
months back that 15 Mbps is their targeted
streaming rate for 4K, and “. . .If you have a
50 Mbps broadband connection, you’ll be
The new H.265 High-Efficiency Video
Codec will make it possible to
stream/play back 2160p video at data rates
comparable to those currently used for
1080p; in the range of 10–20 Mbps. (HEVC
will also increase the use of 1080p streaming
at the expense of 480p and 720p). The
first HEVC chips from Broadcom are being
evaluated now, but we won’t see a wide
roll-out of H.265 decoding in consumer
products until later next year. Netflix is undoubtedly
relying on HEVC to enable 4K
streaming, as will Blu-ray and other physical
To summarize; we’ve got plenty of UHDTVs
to choose from, with more coming
each month at surprisingly affordable
prices. And they’re all big-screen sets
(starting at 50 inches and going up from
there). But, their display interfaces aren’t
fast enough to support 2160p video at
high frame rates and deeper color, nor are
they likely to be any time soon. And aside
from expensive, pre-loaded media players,
there aren’t any sources of true UHDTV
content to watch.