A TUNE-UP FOR THE DUAL TURNTABLE - ThaiHDbox

The WHDI website clarified the difference
between WHDI and DLNA
(Digital Living Network Alliance trade
organization): “WHDI and DLNA are
complementary protocols. DLNA defines
the delivery of compressed media
over an IP network (wired or wireless)
whereas WHDI enables delivery
of uncompressed HD content/video
from HD video sources such as gaming
consoles, PCs, BD players and set-topboxes
to displays.” In both cases, wireless
latency might become an issue for
time-sensitive interactive applications
such as gaming.
There was no discussion of how the
consumer can select an HDMI cable to
ensure it will work. Some assurance
can be inferred from the presence of
an official HDMI logo on the cable, but
that still doesn’t prove that the length
of cable purchased was compliance
tested. [There have been cases where
a shorter length cable passed compliance
testing and the certification was
extended by the cable manufacturer’s
marketing to all lengths in that series.]
[A source of reasonably priced,
possibly well-made HDMI cables and
adapters is Blue Jeans Cable (www.
BlueJeansCable.com). They use Belden,
Canare, or Tartan cable (clearly identifying
which for each product), having
the assembly performed in China. From
their website: “As with all of our products,
we offer a simple and easy return
policy. If for any reason you’re not completely
satisfied, just return the cables,
undamaged, within 30 days and we’ll
refund your purchase price in full.”]
3D
“HD 3D-TV: What You Must
Know” was Michael Heiss’s approach
to explaining in-home 3D video’s history,
status, and idiosyncrasies. “3D is
here, whether we like it or not,” and is a
world-wide phenomenon. Heiss recommended
Mark Schubin’s website www.
SchubinCafe.com as an excellent source
of information on video, including 3D.
There are issues with 3D as a concept,
independent of the implementation:
• Vergence (the distance from the
viewer where both eyes point
to place the object; see http://
en.Wikipedia.org/wiki/Vergence)
versus the focal distance (the distance
from the viewer’s eyes where
they focus to a sharp image); when
these don’t match, nausea has occurred.
The conflict comes from the
eye focusing at the screen while the
stereoscopic image tells the brain
that the object is either in front of or
behind the screen.
• Changing your viewing angle changes
the 3D effect because the left-right
image spacing changes with angle.
• [The interocular distance varies
among people, thus altering the effectiveness
of the stereoscopic effect.]
• [Approximately 7% of the population
can’t see stereoscopically.]
Sports and movies will take the lead
in developing 3D content, but the majority
of programming will be in 2D for
a very long time. Content created for
and shot in 3D (such as most of Avatar)
will be much more visually effective in
3D than content created and shot in
2D and then processed for 3D presentation
(such as Tim Burton’s Alice in
Wonderland).
The 3D formats for Blu-ray discs
have been standardized: frame-packed,
1920 � 1080p24 or 1280 � 720p60
(for example, the left-eye image would
be the odd-numbered frames, while
the right-eye image would be the evennumbered
frames. The display processes
and presents the images as appropriate
for its 3D-display technology). The
Blu-ray player and display must support
HDMIv1.4a with 3D-option for
the 3D content’s auto-switching metadata
to reach and control the display.
E4 audioXpress 12/10 www.audioXpress.com
The 3D-content’s audio data delivery
is the same as under HDMIv1.3, but if
the A/V receiver’s or surround processor’s
HDMI connections are v1.3,
there might be a playback problem.
There are some 3D ancillary feature
issues with Sony Playstation 3s (no details
given).
There are two 3D video-framecompatible
formats: side-by-side and
over/under. In the side-by-side 3D
frame format, each 1920 � 1080 video
frame is made of a 960 � 1080 left-eye
image beside a 960 � 1080 right-eye
image, thus reducing the image’s horizontal
resolution by half. In the over/
under 3D frame format, each 1920 �
1080 video frame comprises a 1920
� 540 left-eye image above a 1920 �
540 right-eye image, thus reducing the
vertical resolution by half. Satellite and
cable systems will distribute 3D in the
side-by-side frame format.
A trade-off for home 3D viewing is
between conventional panel displays
(with adequate frame refresh rates,
3D-processing, and active-shutter 3Dglasses)
and polarized panel displays
(which are more expensive to manufacture
but use less costly 3D-glasses).
One size of 3D-glasses does not fit all
people, especially kids versus adults.
Plus, none of the 3D-glasses are easily
worn by people who wear glasses.
Another problem is that the 3Dglasses
from one display manufacturer
might not work with another manufacturer’s
display, even using the same
3D-glasses technology. For example,
one informal test showed that Panasonic
3D-glasses worked with a Samsung
display, but Samsung’s 3D-glasses
did not work with Panasonic displays.
The cost of active-shutter 3D-glasses is
quite high, especially considering that
you need a pair for each person in your
audience.
Two of the “universal” 3D-glasses are
XpanD (Photo 1) (www.XpanDCine-