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 Some of the information may be out of date.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
(541) 385-9115 or (805) 294-1049
E-mail = larrybend@aol.com or J_Mendrala@compuserve.com
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March 21, 1998
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DTV Tech Note -015
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Sharing experiences, knowledge or anything else relating to DTV, HDTV etc. with your fellow engineers: That's what we are all about. For a copy of our policies and who we will make this available to, please e-mail us. Welcome to all the new subscribers. We now have over 150. We hope you will participate with question, answers and/or comments. To those of you who have been with us and wondered were we've been, read on. New things are in the works.
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Subj: Seattle to get early look at HDTV
From: Randall Paris Dark and Larry BloomfieldKCTS-TV's newest production, "Over Ireland," which was shot in the HDTV format, shows sweeping aerial shots of Ireland's beautiful green country side from it all but friendly coastline to it rock laden hills and cliffs. It is safe to assume that this is partly in preparation for the Hi Def that is coming to Seattle this fall.
"Over Ireland" is excellent subject matter for demonstrating the advantages in the new, sharper resolution and widescreen format. There is no better way of capturing the subtle shades of green, which are augmented by the ruins that cast a sharp relief to the countryside.
KCTS will begin digital broadcasting in early 1999. Several commercial stations in Seattle plan to air some HDTV programming this fall, a year ahead of the deadline set by the government for the switch to digital transmission. Seattle's commercial stations, being in the 12th-largest market, have until November of next year to begin digital transmission. All Public stations however are not required to convert until 2003.
Apparently the influence of the software and technology industries have spurred broadcasters in the Pacific Northwest to embrace the digital revolution in a big way.
By creating their program material initially in the Digital domain using the HDTV format makes it readily adaptable for other digit formats as well, like CD-ROMs etc. It also opens up revenue opportunities for the local station that, due to recent cuts in federal funding, has made them to act more entrepreneurially.
As we all know, both public and commercial stations will end up forking out the big bucks to convert their old analog infrastructures. Estimates of how much a station will spend to make the change, one Seattle expert says is spiral into the double-digit millions.
"It will cost $9 million to $12 million just to pass a digital signal through and have some production capabilities. To completely convert (a station) from stem to stern, you're into higher numbers," one Seattle based network GM said.
KOMO and KING-TV, both network affiliates have already purchased their new transmitters. Seattle's Fox affiliate, KCPQ-TV is rumored to have spent at least $20 million to build an all-digital studio completed last fall, but will have to come up with an additional $2.5 million more for an antenna/transmitter system.
The CBS affiliate, KIRO-TV, is the only major network affiliate in Seattle that will wait until fall 1999 to air its digital signal.
No matter when each stations plans to make the leap, each is faced with the seemingly unending antenna quandary of where to put it, what kind to get, the real estate to house their transmitter, local zoning considerations, tower retrofits etc. One station, KCPQ claims to have one of the best spots, on Gold Mountain, about six miles west of Bremerton. Making space available would be to everyone's advantage, if this were true.
Our studies have shown that the most reasonable approach for both the viewer and the stations is, from many standpoints, to share a common site. It has worked very well in San Francisco for years. Although not in the same building, but basically the same location, is Los Angeles's Mount Wilson. Panel antennas are broad enough that, with good combiners, one tower and antenna system will work for all.
At least one chief engineer has said: "We'd like to collaborate with another station to share costs."
With Larry Brandt, chief engineer for the local Fox affiliate, taking that position, there is some hope.KOMO's management has declined to comment on their plans. KING-TV plans to mount its DTV equipment from the same place where its analog transmitter now hangs.
Seattle's UPN affiliate, KSTW (in Tacoma), is in a holding pattern. They don't plan to make any moves until the consumer market shows the public is starting to purchase home digital equipment. It sounded to us like a "we'll buy when they buy" type of a situation. It is obvious KSTW doesn't intend to broadcast HDTV this fall or any sooner then they have to.
When asked when they thought consumer acceptance and subsequent purchase of the new digital equipment might begin to justify their investments, none we spoke to have a clue. On executive said that it was anybody's guess just how quickly the Seattle viewers will replace their old sets.
In speaking with an executive at a consumer chain in the Seattle area, we were told that things would be slow at first. Asking to remain anonymous, he said: "Most people can't afford the $5,000 to $10,000 price tags even the smallest model HDTV sets will have." When asked why so much, his response was that the consumer is getting so much more, even with the smaller sized 40-inch diagonal screens, the rectangular like movie theater screens, the elaborate speaker system and the new cabinetry and so on. With a reassuring note in his voice, our executive concluded by saying: "Once the public has a chance to see the new formats, the seed will be planted. It will only be a matter time until they'll have one in their living rooms, then bedrooms and so on."
When we mentioned that CEMA had estimated that 30 percent of all U.S. households would have digital sets by 2006, his response was, "we sure hope their right." Our Mr. X was fast to point out that he'd been told there would probably be a number of converter boxes with various features available to down-convert DTV to the older type sets. He said, they plan to stock some of them also. He said, "At least the consumer could get what is now studio quality pictures in their home for a modest investment."
Our Mr. X did emphasize that available programming that truly demonstrated DTV's superior quality would go a long way to expand the public interest and sales. He continued, "the tight-lips of the local stations and networks in this area have me a little concerned." Unfortunately none of the commercial networks have indicated which of their syndicators will provide their products in a high-definition format.
By contrast, KCTS has a library of HDTV programs including the already mentioned "Over Ireland" and, in addition to this, "Chihuly Over Venice" -- documenting glass blowing in a flourish of hue and texture in high-definition -- produced by its staff. Like other high-definition programs KCTS has created, "Over Ireland" has aired in an analog format already this month.
The public station has shot about 14 high-definition projects and will rebroadcast them, including its "Over" series of aerial programs -- "Over America," "Over Beautiful British Columbia," "Over California" -- when the PBS goes digital in 1999. It appears that KCTS is living up to the PBS slogan, "If PBS doesn't do it, which will?"
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Subj: Spreading their wings
By: Larry BloomfieldWhat's going on around us while we're building terrestrial DTV? Well more than the camels' nose is in the tent. DirecTV recently announced it has acquired Ku-band transponder capacity on the Galaxy III-R satellite from PanAmSat Corp. DirecTV will initially lease four Ku-band transponders aboard Galaxy III-R.
Galaxy III-R is currently used by a multinational company, Galaxy Latin America, to provide DirecTV service in Latin America and the Caribbean. DirecTV will commence using the Galaxy III-R capacity after it is replaced by the recently launched Galaxy VIII-i satellite. DirecTV will have the ability to expand transponder capacity on Galaxy III-R, ultimately so they may offer up to 120 channels. The additional capacity will be dedicated to special interest programming, niche programs and future business-to-business applications. Galaxy III-R will also serve as an additional platform for the launch of high definition television programming later this year.
In the same announcement, DirecTV spoke of arrangements for the development of a new DSS model, which will include one 21- by 35-inch elliptical satellite dish, to receive new Galaxy III-R programming as well as all existing DirecTV programming from DSB 1, 2 & 3.
Initially, the new receiver system will be manufactured exclusively by Hughes Network Systems (HNS). It will be capable of receiving signals/programming from two separate orbital locations, Galaxy III-R at 95 degrees West Longitude (WL), as well as providing access to the more than 175 channels of DirecTV programming currently delivered from their three spacecraft at 101 degrees WL. HNS will employ the same digital technology it currently uses for its 18-inch dish systems to create the new DSS product.
The initial programming slated for distribution from Galaxy III-R will be a lineup of foreign-language offerings provided by Ethnic American Broadcasting Co. (EABC) featuring programming for Russian Ukrainian, Italian and Arabic speaking people as well as programs for Asians from the Indian subcontinent. The agreement with DirecTV provides EABC with sufficient capacity to distribute as many as 20 leading ethnic channels from countries around the world.
DirecTV and Galaxy Latin America are developing Hispanic programming for the U.S. market, but no specific decisions have been made yet with regard to partners or satellite platform for such offerings.
Larry Chapman, executive vice president of DirecTV, speaking of the new subscribers to this new system, said: "Using the new HNS equipment, these subscribers will not only have access to unique and previously unavailable programming, but also will receive all of the DirecTV programming available at our 101 degree location."
Lourdes Saralegui, PanAmSat's executive vice president, said: "DirecTV's expanded service offering will become PanAmSat's first direct-to-home platform in the United States and our seventh worldwide."
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Subj: Giant Screen TV
By: Jim MendralaHow would you like to have an 8-foot diagonal TV for your "Station/Lobby"? Well, the other day I visited ProLux Corporation. Steve Wilson, President/CEO, took me on a tour of their facility. They build video projectors called the "WallZapper/Pro1200V and WallZapper/1200S".
The difference between the two is primarily the number of pixels. In the 1200V the resolution is 640x480. The 1200S is 800x600. The projectors on a flat screen produce a spectacular picture from a good video source, such as S-Video. The projector displays what is in the image very well. The projector can input on BNC connectors: Composite video, S-Video, NTSC and PAL signals as well as RGB or XGA (1024x768), SVGA (800x600), and VGA (640x480).
The input video goes through an interpolative line doubling, comb filter and converted to progressive scan for display. The projector is a single panel 6.4" TFT LCD. It accepts a 16.7 million colors (8-bit color) and displays a 2.1 million picture.
Now comes the fun part of what I saw. They took the 1200V and put it into a folded optics rear screen projection box with a screen of 8 feet measured on the diagonal. The image tends to overpower you at first because it is so big but then as you look at the screen from a farther distance, the image really stands out.
The signals I looked at were from an off air antenna at first, then from a DVD. The picture off air was not too good as there was multipath, ghosting and poor signal strength, mostly because the factory is at the bottom of a valley along Interstate 5 just south of San Juan Capistrano. The DVD looked much better.I could just imagine how it would look on a DSS like DirecTV.
There are a lot of applications for a Big TV, such as TV station lobbies, theaters to run promos of coming attractions, hotel lobbies, airport waiting areas, pizza parlors or sports bars, etc. It could also be used as a background for a newscaster without having to install a "video wall".
The unit stands a little over 7 feet high. For more info check out their web site at: http://www.prolux.comThis is truly a BIG SCREEN TV.
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Subj: What's my Line -- PC or TV?
By: Larry BloomfieldIt wasn't too long ago that an operations manager at a station I work for asked if there was an easy way of getting the presentation from a PC onto tape, without much loss of quality. Well the DTV station of the future will need to know this too, so I checked out several approaches and a few systems. None of them really delivered the quality either of us wanted. We thanked the vendors and did without. It appears that a new product recently introduced will fill that need.
Focus Enhancement, Inc. (FEI), a Sudbury, Mass. company, has announced that they have developed a PC-to-TV digital video co-processor. FEI says: "The new TView FS300 video co-processor is currently the most flexible PC-to-TV video convergence chip in the market. It works with TVs, PCs, or set-top boxes to display computer images without any additional software drivers, or external circuitry." The others I had tested were no where this simple in approach.
What makes the TView FS300 unique is that it is the only such device, on the market, which doesn't require software to be VGA chip independent. Because of this, integration of the Focus technology is much easier and more cost effective than other products of this type. FEI says their technology is truly "plug and play" since it will accommodate any refresh rate up to 90 Hz. Reports have it that The FOCUS FS300 digital video co-processor is the only PC-to-TV encoder that supports resolutions of 640 x 480, 800 x 600, and 1024 x 768. Another appealing feature of this device is that it also provides under scaling, compression and visibility at levels exceeding other devices of this kind.
The Focus technology will be available through several manufacturers. FEI has established licensing agreements with Philips, Fairchild Semiconductor, Picture-Tel, Zenith and Apple Computer, with negations in the works with several other undisclosed companies. FEI tells me they have received very positive feedback form these manufacturer on the superior video quality and performance of their TView FS300 PC-to-TV ASIC.
Marketed under their own label, the "TView Gold" is their top-of-the-line PC- to-TV consumer product, featuring IR remote control, video pan, video zoom and video freeze. The TView Gold can handle PAL/NTSC both composite, and S-Video signals and comes with all cables needed for most hook ups. It stands to reason that some type of interface device will be needed, such as a TBC or frame synchronizer, if you wanted to be in time with your plant.
It is designed to be compatible with the latest 1024x768-video resolution PCs. According to one computer trade publication, "the TView Gold has the most advanced signal processing circuitry to reduce artifacts and line crawl"
FEI also makes a mid-line unit, the TView Silver, which comes with most all of the features of the TView Gold and sells for about 30% less. The "Silver" only supports 800x600 resolutions. When reviewed by a different computer trade publication, they say: the TView Silver offers TruScale image compression technology, which fits the computer image on the television."
These devices could very easily find their way into your station with applications not limited to Creative Services or News. The advent of digital still cameras displaying on PCs, not to mention the plethora of PC based graphics libraries, has challenged engineers to find a "quality" way to interface a PCs displays with their plant. An additional challenge is to be able to do so in such a way that most anyone at the station or facility, especially the non-technically adept personal, can get the "pictures" from one media to the other. FEI has opened the door in making the transition smooth, simple while maintaining a reasonable level of quality. Keep in mind that if the quality isn't there to begin with; don't expect it to be there when it comes out of the Focus equipment. Just think, now even an intern or that "all thumbs" guy can take PC based material and make it ready for use in the wonderful world of television with a minimal amount of training.
For more information, check out their web site at: http://www.FOCUSinfo.com. If you contact them for any reason, please tell them where you saw this article. Thanks Larry
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Subj: Sony's HDTV Telecine
By: Jim MendralaAt the Society of Television Engineers (STE) meeting Thursday evening, March 19, 1998, Luke Freeman of Sony gave his presentation on the FVS-1000 Multi- standard Sony Telecine. The telecine differs from most telecines by using an electronic/optical pin registration system. This allows frame rates up to 60 pin registered frames per second (fps) and high speed slewing of the film in the shuttle mode. Other features are an updated version of the Peterson/Bell & Howell type RGB lamp house and a sphere to illuminate the film. The sphere allows diffuse light to illuminate the film image greatly reducing dirt and scratches. Color balance is achieved by controlling the amount of red, green, and blue light into the sphere and then on to the film.
Film in most telecines uses the edge as a reference, but its tolerances are pretty course compared to the reference sprocket hole that the camera pin uses when photographing an image. Sony achieves pin registration by sensing the capacitance of the sprocket hole on an x-axis and y-axis and sends data to two servo-driven 1/8 inch thick pieces of glass to move the image relative to the camera to bring the image back to the point that is in register with the previous frame. The film itself does not move during this registration process, only the image moves.
The film can run at either 23.97, 24, 25, 29.97, 30, 59.94, or 60 fps making it a multi-standard telecine. Images are progressively scanned in a 16x9 format and then interpolatively sub sampled to the output desired. This means that you can output RGB, YUV, NTSC, PAL, or SECAM at the appropriate frame rate.
Example: if the film is run at 24 fps, you can output at RS-140 2:1 interlaced with electronic 3:2 pulldown or you can output the film at HDTV as 1080i x 1920 at 60/30/2:1. You can also run the film at 23.97 and output at CCIR-601 59.94/29.97/2:1 as well as HDTV at 1920px760 60 fps progressive. The machine will also output at 480px702 progressive at 24 fps making it a fine machine for the DVD and MPEG-2 encoding. By running at 24 fps, there is about a 30% savings in bits with no loss of quality to the image. (Presently the 3:2 pulldown that was inserted by the telecine is extracted in the MPEG encoder and put back in at the MPEG decoder.) It was not made clear if all of these outputs were available in the basic machine or if they are options.
The STE is a Los Angeles group of television engineers founded in 1941 and was instrumental in forming the NAB. Bob Bajorek, is the current president. For more information, check out their web site at: http://www.sony.com. If you contact them for any reason, please tell them where you saw this article. Thanks, Jim
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Subj: What's Wanted at NAB '98
By: Larry BloomfieldThanks to all of you who answered our questionnaire. This is what we came up with from that. This composite article is probably better than saying the same thing over a dozen and a half times, as was the case with one response.
Terms like "Big, massive, not enough time to see everything and "WOW" were used to describe last years NAB. There are so many factors from the press releases I've seen so far, conversations with fellow engineers and knowing that we're on the brink of a whole new world of technology, indicates that NAB '98 will be even bigger. With this in mind and the promise of probably the most intense trade show in our industries' history, I called several associates, who's opinions are held in high regard by their peers, to see if I was dreaming or if I was on the right track. These are members of our industry who, when asked how long they'd been going to NAB gave me ranges form on and off for the past few years to over 33 years. The quotes not attributed to anyone in particular are a summation of what I was told by these gentlemen.
Some of the initial comments I got were: "We're going to see the biggest show in NAB history." Most all said: "wear comfortable shoes." One even said: "if comfortable shoes were needed in years past, you'd better have at least two pair this year." "You'd better plan this one in advance or you'll miss something you wanted to see," was another comment. One director of engineering went so far as to tell me he was going to map out the various venues floor plans, mark the vendors and displays he wanted to visit and stick to it. So unless you have some kind of agenda or plan, you'll probably not see everything you need or want to see.
There's no question in my mind after talking to my associates that this is going to be the year for DTV and high definition equipment. What did they say they wanted to see? (I'll address what they will be buying later.) From their comments, there's no question. Those companies who'll have displays at NAB '98, if it's not too late, should include these kind of things in their bag of tricks. "Economical 601 stuff," I was told. Fairly consistent with everyone I spoke to was this reply: " .....hope to see everything from RF systems (transmitters, towers and antennas), STL's with NTSC and DTV capabilities, and anything else DTV or HDTV." Interest was also express in such things as multi-format cameras, format converters, Mpeg stream splicing, MPEG 4:2:2 Video servers, compression equipment, up converters, multiplexing capabilities, DVD and virtual sets. I was surprised at the interest express in consumer products such as flat panel displays. Several engineers told me they were interested in: "Not only HDTV, but multi-casting and its possibilities." One concern that was expressed was there wouldn't be any useful information on DTV adjacent channel operations.
When I asked them what they specifically would be looking to buy, again, by the numbers, I got the same answer, almost in unison: "DTV products - acquisition, production, distribution, and broadcasting, DTV encoders, digital microwave, test gear and HDTV system components." Draw your own conclusions, but it sounds like most attendees will be buying what they want and expect to see. Several made the cautious observation that although they were going to get their feet wet in DTV and look at HDTV and multi-casting, there was still a kind of: " ....we want to see which direction the manufacturers and big boys are taking and what everyone else is purchasing" attitude. Interest was also expressed in buying nonlinear edition equipment and station automation equipment, but most weren't sure if what was available would handle both digital and analog signals.
Tied to the purchase issues was interest in finding complete, typical business plan engineers could tailor to their particular situation. This would be a big help in budget preparations, which are a big part of most engineers' lives in this day and age. "If we could have the "bean counters" boiler plate jargon, we know what we need and can sell them on our budgets more easily, leaving us more time to address the technical issues," seemed to be the common thread in this line of thinking.
Those who express an interest in the conference sessions, again, were nearly all unanimous: "Anything about building DTV/HDTV." More specifically, "those session relating to DTV transmission issues, data broadcasting for DTV, DTV audio workshop and 8VSB Modulation." It was interesting to note that several mentioned the SBE meetings. They said they wanted to: "see where the shakers and leaders think we are headed as it relates to technical personnel."
On the other side of this coin, I was curious to know what my associates thought would draw the least interest. "Anything Low Def. or analog," seemed to top the list. When pressed to be more specific, I was told: "Analog switchers, routers, and effects, Video disk, large screen SDTV projection, and Analog Cart Machines." One even mentioned Tectan, saying: "They appear to have gone out of business." When I heard, "Anything Radio," coming from a television engineer, that didn't surprise me much.
This is going to be a bumper year for manufacturers. The trust that engineers have in their sales representatives has got to be founded in the fact that the sales people know what they're talking about. Most engineers expect the sale people to be as knowledgeable about television as they are and to be "experts" on the device they are trying to peddle and it's application in their plant. One thing I know, and was express most clearly to me, "we (engineers) don't like to go to NAB, see a great product that the manufacture can't deliver." Several items were mentioned that were shown at NAB '97 which still can't be shipped.
Advice to salesmen: If you know your stuff and know what you're talking about, you'd better have lots of pens, inked up and ready, with order pads handy. You're gonna need 'em! The way the engineering folks are talking out there, if the sales guy knows his product, where it can fit in into each station they will probably right a lot of orders. I don't see where there'll be much time for parties, as in past years. The sad part of all this is I don't believe there are enough savvy salesmen with each vendor, who has a "worth looking at" product, to go around.
NAB '98 is the year of "DIGITAL" and "HIGH DEFINITION!" Make no mistake about that. This is an excellent learning opportunity for all engineers involved in this transition. We will not get a better opportunity to meet and speak with the people who design and built the very equipment we will be buying and installing: to look and operate the very items we will be living with for who know how long. I can see not going as a short cut to possible disaster. See ya there! I'll be there with the Broadcast Engineering magazine group. Jim will be incognito. If you see Jim, or me say HI.
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The next step:I'd planned to do a story on 3D-TV and MPEG-4, but had too many other things to check out this past month. I'd be interested in hearing what any of you might think the next step television would be taking after DTV is giving us our various kinds of signals. 3D-TV maybe? And any comments on MPEG-4. Saw a chip for a camera that is used in a telescope. Wow it was big. How about 7K X 7K pixels? And we're worried about pixel count in color cameras? Have covered some very interesting stories for Broadcast Engineering. Look for my feature on DTV antennas soon. Stay tuned. Thanks Larry
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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 (541) 385-9115, (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.>>> E-mail: larrybend@aol.com or: J_Mendrala@compuserve.com <<<
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