-
Archived
Tech-Notes
Published by: Larry Bloomfield & Jim Mendrala
The following are our current e-mail addresses:
E-mail = hdtvguy@garlic.com
or J.Mendrala@ieee.org
We have copied the original Tech-Notes below as it
was sent out. Some of the information may be out of date.
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DTV
Tech Notes
%
Larry Bloomfield & Jim Mendrala
(408)
778-3412 or (805) 294-1049
E-mail = larrybend@aol.com or J_Mendrala@compuserve.com
February 15, 1999 DTV Tech Note – 025
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Digital Super
Bowl Party
By Jim Mendrala
On January 31st
Digital Arts & Engineering held a Digital Super Bowl Party at
B.B. Kings Blues Club on City Walk, Universal Studios, CA. The idea
was to show to producers and directors of television and music video
content state of the art DTV (Digital Television) from a consumer
standpoint.
Several manufacturers
including Hitachi, Panasonic, Digital Projection and Stewart Filmscreen
participated, as well as The Good Guys and Audio Rents. The Good
Guys provided the DTV Panasonic DTV receiver and Audio Rents a Yamaha
Dolby AC-3 decoder.
The demo was
set up with two living room settings using the new Hitachi DTV ready,
model number 60SDX88B, 60 inch sets.
A 12 ft. by 9
ft. screen with a 15 ft. diagonal provided by Stewart Filmscreen
was set up on B.B. Kings stage and the image on the screen was projected
from the balcony via a Digital Projection Power 7gv projector.
The projector
with it’s 3 chip Digital Micromirror Device (DMD) provided 6,500
lumens on the screen. That’s much brighter than what you see in
most theaters.
Before the game, one Hitachi set was displaying
the images and sound from a standard DVD disc player in the wide
screen mode. The video from the DVD was fed to the set using the
S-Video connection. Audio was in 5.1 channels. The center, left
and right speakers were in the set and two external Tannoy speakers
powered by the Yamaha amplifier provided the surround sound.
There was provisions for a sub-woofer but we didn’t use it. The
rumble and other low frequencies sounded okay though. With the line
doubling used in the Hitachi, the picture looked very good and some
viewers mistakenly thought it was HDTV.
With an off air
antenna, the NTSC pictures on the Hitachi did not look as good as
on a standard NTSC receiver. The problem was that the picture had
ringing artifacts in it. Since the same antenna was used to supply
the other TV sets, it was interesting how the same stations looked
on the various receivers fed by the same antenna.
For the Digital Projection’s Power 7gv projector,
three video sources were used. One was the Y, Pb and Pr output of
a Panasonic TU-DST50 DTV receiver. A second was the RGB output of
a W-VHS analog HDTV player, and the third was the composite output
of an old Betamax VCR. The Betamax was used as a tuner for
the game which was broadcast only in standard NTSC but with stereo
sound over Fox’s Channel 11 in Los Angeles.
Amazingly the
best NTSC picture displayed was from the old Betamax VCR composite
output (used as a tuner) and projected onto the big screen using
the Digital Projection’s Power 7gv projector.
The 50 inch NTSC
TV’s fed from the cable system at B.B. Kings Blues Club were quite
a bit noisey, like fringe Grade B.
The 60 inch DTV-ready
Hitachi’s, when tuned to the NTSC channels, had ringing in the picture
which seemed to be related to the comb filter used to filter out
residual 3.58 MHz. However, the DVD using the S-Video connection
from the DVD player looked very clean.
When the Panasonic
TU-DST50 DTV receiver was tuned to the 5 DTV stations on the air
in Los Angeles, there was excitement and disappointment. The DTV
receiver, when switching from channel to channel, took about 5 seconds
to lock up and display a picture.
KCBS-DT was running
a HDTV travel type of program about Los Angeles. It was shot in
HDTV and was outstanding. It looked as good as a movie on the 12
ft. by 9 ft. screen. The image was letter boxed by unused pixels
above and below the image. (The native resolution of the Digital
Projection’s Power 7gv is 1024 by 768 in a 4x3 aspect ratio. The
HDTV picture was down converted to fit this native display.) The
rear screen projected Hitachi’s displayed a very good picture also,
but the image was not as sharp as Digital Projection’s projected
image. It was more like the DVD image.
KTLA-DT and KNBC-DT
were up converting the regular NTSC programming and, compared to
KCBS-DT, were disappointing. Even though KTLA-DT was the first on
the air with DTV and HDTV and broadcast the Rose Parade in HDTV,
a call to them revealed that they had no HD D-5 to play any HDTV
on. The DTV broadcast did not look as good as the same NTSC broadcast
viewed through the old Betamax VCR’s composite output and projected
by the Power 7gv.
KABC-DT was not on the air before the game.
Neither was KCOP-DT when we selected their channels.
DTV after 3 months
is still in its infancy.
The antenna,
a Radio Shack VU-75XR, had a clear shot at Mount Wilson where the
DTV signals were emanating from. The output of the antenna was amplified
by a Radio Shack signal amplifier p/n 15-1108. It has a maximum
of 20 dB of gain on the UHF channels and 25 dB on the VHS channels
and is adjustable. The need for the antenna-mounted signal amplifier
was to make up for the loss of signal through 350 feet of RG-6 coax
and the four way splitter used to fan out the signal to the two
Hitachi’s, the DTV receiver and the Betamax VCR. Pointing of the
antenna was done by tuning a small portable TV, connected directly
to the antenna, to channel 34, KMEX-TV and Channel 11, KTTV-TV.
Ghosting on channel 11 was minimized by rotating the antenna slightly
away from Mt. Wilson and more towards Mt. Hollywood. There was plenty
of signal at the antenna as we were only about 15 miles away, as
the crow flies, from Mt. Wilson.
Now, I know the
Digital Projection Power 7gv is a very expensive projector, but
it was used as a reference point to compare what is being broadcast
to what is being displayed on the consumer DTV sets.
The HDTV that
KCBS-DT was broadcasting was superb. Everyone was awed by the clarity
even when blown up to 9 ft. high and over shooting the 12 ft. screen
by 2 ft. on either side. We had to put up some black polyvinyle
on the windows to darken the light spill into the living room settings
and help the rear screen projection Hitachis cope with the ambient
light.
Everyone agreed
that the HDTV picture was very good -- no noise, no ghosting, excellent
color, no obvious MPEG encoding artifacts, and CD quality sound.
The picture was almost lifelike. KCBS-DT did a very nice job. KNBC-DT
was the worst. Even though they were not broadcasting an HDTV picture,
the DTV transmission was full of NTSC and MPEG artifacts. Perhaps
this was because they were taking the composite feed to the NTSC
transmitter and using that signal to be encoded by the MPEG encoder
to DTV instead of component video. KTLA-DT was a little better but
still not quite as good as their NTSC transmission. The DTV pictures
did have excellent signal to noise and no ghosting whatsoever.
It was planned
to have a RCA DSS receiver to view the Super Bowl. The night before
the event everything was working fine but Sunday morning it rained
and the main processor in the DSS receiver failed. This, bgy the
way, was the only time that the DSS receiver was not plugged into
a surge protector. RCA says that if you buy there surge protector
they will extend the warranty on the DSS receiver to 3 years.
The W-VHS HDTV
player looked very good although it was analog. A few thought it
was film.
My conclusion
is that HDTV broadcast by DTV on a big screen is awesome. Up-converting
NTSC to digital to feed the DTV transmitter is not a very good idea.
If SDTV is to be transmitted it should be sent to the transmitter
in component form not composite and should not be upconverted to
HDTV as the receiver outputs the image to either 480p, 1080I anyway.
Decoding NTSC to feed the MPEG encoder with other than an expensive
NTSC decoder is a visual disaster.
DTV is new to
the terrestrial broadcaster. In a several more months, the broadcaster
should be transmitting a picture at least as good as the DSS Satellite
people have been doing for the last couple of years.
Things
are on the move at SMPTE
By Larry Bloomfield
Information has come our way that indicates that
SMPTE is making some major changes in their committees. An
inside source says it all has to do with the slowness in establishing
standards for digital television and ANSI's dim view of how SMPTE
has been approaching the establishment of their standards, in general.
It sure seems strange that they would wait until the ship left the
dock before deciding the crew needed to be changed.
It's almost like SMPTE was oblivious that digital
television was going to be launched this past November, but on the
other hand there are those who think the change is very long in
the tooth in coming. Despite many significant changes in both
the film and television industries, SMPTE is essentially the same
organization as when it was founded back in the late 20's.
A chair of one of the new committees said that until this major
restructuring, SMPTE was a "good old boy's " organization
that got together to reminisce rather address new technology.
There is little question among those who have
kept abreast of the technology that most in the industry have not.
The seeming lack of direction and understanding in the area of digital
television is truly scary. Proof of this can be seen in recent
surveys conducted by such reputable firms as SCRI. A good
look around would certainly point out that some of our most trusted
suppliers are trying to take advantage of this situation by pushing
the industry in directions that it may not necessarily be in its'
best interests and all for their corporate bottom lines.
It certainly is better that the wake up call
came now instead of later when more of the industry had gone further
down the digital path. More information on this subject will
be forth coming as we can get people close to the situation to talk
about. It seems SMPTE doesn't want to wash their dirty laundry.
Both Jim Mendrala and I are members of SMPTE
and since we who write for the DTV Tech Notes have no advertisers
to please or any other allegiances other than the highest of engineering
standards, we'll make every effort to keep you informed as this
situation develops. What to see it for yourself? Go
to the SMPTE meetings.
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Is the
Peacock Changing Colors?
It was only a few months ago that a longtime
friend of my, from back in the days when we both worked at the Peacock
factory (NBC) in Burbank, shared with me that he'd recently walked
through our old, but familiar, "stomping grounds," at
the junction of Olive and Alameda in Burbank. He said:
"It seemed like a morgue." He told me that yes there
was production going on, but the other operational areas seemed
all but abandoned. SkyPath, which he and I had help build,
was totally dark. Is this all part of something in the wind?
I've heard rumors, seen stories and been told by people in the know,
that GE has been positioning NBC for possible sale.
Another friend, who is in a position to know,
at NBC in New York, and has asked to remain just that, told me that;
"NBC, and all of the other nets had big layoffs," around
the end of September. He said, "We lost most of our real
engineers. CBS laid off their news dept and ABC did layoffs from
top to bottom." Sounding like my Burbank friend, he said,
"The place is very empty now, very depressing now that everyone
has gone. It is like it was when I worked on the weekends.
Lot of people getting into other things, both the people that were
laid off and the people that are still here."
In further conversation, my source mentioned
that GE had offered 49 percent of NBC to Sony Picture Entertainment.
I hope General Sarnoff doesn't turn over in his grave. He
continued, saying , that GE goes into these "partnerships"
offering minority ownerships. He did say that he wasn't sure
if it the stations were included in this offer or not.
It will be interesting to see what happens. Oh.
A point of trivia. It was NBC who had the Kate Smith Show;
remember -- "When the Moon Comes Over the Mountain."
It was this vocally gifted, rather large lady who was the inspiration
to the expression that: "The fat lady hadn't begun to
sing." My sources tell me she's on the way to the microphone.
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Beyond
the Label
Character Generators (CG) have been around for
a while and aren't particularly newsworthy; unless the one you're
talking about is new, different and does a lot of really "neat
things." That is the case with this "new box"
from Pinnacle.
Within the past year or so, while Chief at my
last station, I looked at quite a few CGs trying to find a replacement
for an aging workhorse that was becoming increasingly more undependable:
an all too familiar story, I' sure. I had almost every known
manufacturer, or their rep, stop by to show me their "goodies."
As an NBC affiliate, we wanted to look like them, but hardly had
the budget to cover the cost of the paperwork the Peacock factory
used to buy their CGs with.
This fall, when I was invited to have a "look-see"
at Pinnacle's new FXDeko, I was truly impress with what I saw and
all that it does; shatters, 3D space rotations, warps into position,
and more. At the risk of sounding like a product review or
infomercial, I'd like to share with you only the things that impressed
me the most and let the salesmen take care of the rest.
Besides being a character generator that will
handle most any font library going, including Chyron's, it's also
a digital video effects (DVE) generator that will take two channels
of external video and put them though the same gyrations it puts
the fonts through. It interfaces with other systems such as
equipment made by Quantel.
Speaking of fonts, I had a very difficult time
a few years back finding a CG that would handle non-Roman language
fonts. Although most places don't have the requirement, it's
nice to know that the FXDeko supports Arabic, Hebrew, Cyrillic,
Chinese, Japanese, Korean script and probably a few I can't remember.
You never know when you might get a job requiring one of those systems
of script.
The built-in Frame Grabber lets you snag images
from video clips, etc., extending your Creative Services' ability
to come up with unique and good looking local material while retaining
that certain "image" and still looking distinctively different.
Being NT based, with both hard drive and standard
3.5-inch floppy drive for memory, it's compatible with other similar
based equipment. The "box" is reported to be DTV
ready (whatever that means). It runs in all currently popular
analog formats; NTSC, PAL S-Video, etc. Inputs are RGB, YUV
or serial D1 and the outputs are the same plus SMPTE/EBU and key.
The FXDeko lists out at about half the cost of
the "industry leaders" comparable top of the line.
I'll let you go away trying to figure out who that is. I'm
purposely not going to mention price as we all know the FXDeko will
ship for various prices, depending on who you "strike a deal"
with. Good luck and good looking.
Check out Pinnacle's
web site at: http://www.pinnaclesys.com
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Local into
Local Soon?
The headlines
read: "Local TV On Satellite Hires Veteran Broadcaster as Chief
Operating Officer"
Since there are over 1600 television station
in the USA, it would seem to me that Local TV on Satellite might
be a very ambitious venture for these folks. Since some of the cable
folks are balking at the new DTV/HDTV formats and are iffy about
having to carry more than one of the two TV station from the same
operator in the same market, maybe this is an answer. It may
also be an answer to the problem of translators and what's to become
of them. Remember that many of the communities in the and
West of the Rockys depend on translators for their TV service.
Portland, OR stations along have anywhere from 50 to 75 translators
each. In the 202nd market, Bend, Oregon, I had
8 translators when I was Chief Engineer there, but with the number
of stations to be considered across this fruited plane, this is
quite an undertaking!
According to
the press release, John H. Hutchinson, a veteran broadcasting executive
will join Capitol Broadcasting Company, Inc. as Executive Vice President
and Chief Operating Officer, a new position.
Hutchinson, will
have the job of implementing LTVS's plan to deliver all local television
stations in the U.S. via satellite, giving consumers alternatives
to their cable providers and translator systems. He joins LTVS after
28 years with Jefferson-Pilot Communications Company, the last seven
as President of the Television Group and General Manager of WBTV
in Charlotte, N.C. During his career, he's held a variety of broadcast
management positions. Hutchinson is a member of the Television Board
of Directors of the National Association of Broadcasters and a District
Representative on the CBS Affiliates Advisory Board. He holds a
BA degree from the University of North Carolina.
Jim Goodmon,
President and Chief Executive Officer of Capitol Broadcasting Company,
Inc., said, "John Hutchinson's extensive broadcasting experience
will be a huge asset as LTVS develops its business plan to provide
meaningful competition in the multi-channel video programming market."
When asked about
his new position and about LTVS, Hutchinson responded, "I believe
LTVS has the technological 'local-to-local' solution that broadcasters
and Direct Broadcast Satellite (DBS) providers need to give consumers
greater choice, better service and lower prices. I look forward
to making local television via satellite the industry standard."
Local TV on Satellite,
LLC was founded in 1997 by Capitol Broadcasting Company, Inc. and
its subsidiary, Microspace Communications Corporation, to develop
and implement a plan to deliver all local television stations in
the U.S. via satellite. Using "spotbeam" satellite technology,
LTVS would make DBS providers fully competitive with cable, providing
quality transmission of all local television stations in all local
markets. Current laws prohibit DBS providers from carrying local
stations. Congress is considering legislation this session that
would change all that, guaranteeing all consumers access to local
programming from all providers.
CONTACT: Capitol Broadcasting Company,
Inc. James F. Goodmon 919-821-8504
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Spectrum
for Lat-ta-num
If you're not
a "Trackie," then you may not know that lattanum is the
intergalactic money of the future and what it will take "a
lot of" if you want a frequency to operate on in the future.
The auctioning off, to the highest bidder, of
frequencies and spectrum is at hand, and will be the way of the
future, in all services under the auspices of the FCC. The
successful party, who vied for an available frequency, will no longer
be a matter of the most qualified or necessarily worthy, but the
one with the most bucks or latinum.
Many broadcast engineers and technicians are
also amateur radio operators. I'm no exception, KA6UTC.
Those who are may recall, not too long ago when a large chunk of
the 220 MHz amateur band was wrestled away from them by the "guardians
of the air waves," the FCC.
Want to know what happened to it? Read
on! In report number WT-98-36, the Commission, in a harbinger
of things to come, announced they had, in about a five-week period
and in their 17th auction, raised $21,650,301.00 in net
bids after 173 rounds for the 220 MHz service.
I can't help
but wonder if Daddy Warbucks, of Little Orphan Annie fame, had been
an amateur radio operator and had bid $22 million, if we couldn't
have retain that spectrum for amateur radio use?
For more heart throbbing details see the FCC
web site at: http://www.fcc.gov
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Pluto's
HyperSPACE
In a recent survey I took of broadcast engineering
managers in the top 10 markets, they told me, by the numbers, that
one of the biggest problems they were having making digital TV a
reality was the availability of equipment. Since many television
stations have made the transition to an analog video server as their
main stay for commercial play back, program delay and other familiar
uses, it has become an important item to be considered for the digital
plant as well. News of such a device certainly deserves mentioning.
When
someone told me that "Pluto" had developed such a device,
all I could thing of was the mythological Roman god, the ninth and
farthest planet from the sun or thoughts of the gangly, floppy eared
Disney dog, but certainly not a video server. Was I ever surprised!
I wasn't too far off track when I thought of
the planet because Pluto has developed, what they are calling, The
HyperSPACE HDCAM. Now the HDCAM part of the name comes from
Pluto's association with Sony. The HyperSPACE HDCAM is a playout
server designed to be used in HDTV broadcast applications.
It is random-access, so it should work well with station automation
and can be put to work as a Hi-Def disk recorder for post-production
applications.
The way the project went together was that the
R&D team at Pluto Technologies International used the HDCAM
compression technology developed by Sony. The product will
allow broadcasters, cable operators, Direct Broadcasters and Post-productions
houses to operate in one environment (HDCAM) minimizing "generational"
video quality loss that improves the on-air product.
The HyperSPACE HDCAM is designed as a "plug
and play" device and is initially being offered in several
packages ranging from a simple server/encoder, for reliable storage
and random access to media, to larger systems that include an editor,
switcher and VCRs. No mention was made as to video formats
accommodated. For additional information, visit either the
Pluto web site at http://www.plutotech.com
or the Sony web site at http://www.sony.com/professional
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The DTV Tech Notes are
published for broadcast professionals who are interested in DTV,
HDTV, etc., by Larry Bloomfield and Jim Mendrala. We can be reached
by either e-mail or land lines (408) 778-3412, (805) 294-1049 or
fax at (805) 294-0705. News items, comments, opinions, etc.,
are always welcome from our readers; letters may be edited for brevity,
but usually not.
>>> larrybend@aol.com
--------- J_Mendrala@compuserve.com <<<
DTV Tech Note articles
may be reproduced in any form provided they are unaltered and credit
is given to the DTV Tech Notes and the originating authors, when
named.
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