Global HDTV: the Elusive Quest for Common Standards

Across the globe, hopes for a universal origination and delivery format for digital TV (at least for high definition) have been dashed by the development of more digital formats and encoding systems than exist in the analog world. This has exasperated...
April 1, 1999

Across the globe, hopes for a universal origination and delivery format for digital TV (at least for high definition) have been dashed by the development of more digital formats and encoding systems than exist in the analog world. This has exasperated many, like producer/distributor Bo Landin, executive director of Scandinature in Sweden. ‘I had a dream that with digital we’d all unite around some common standards. Instead, there are more formats, standards and confusion than ever!’

The emergence of three distinctly different digital broadcast systems (added to the already-existing multiple analog systems) competing for exclusive allegiance among the world’s digital nations has made the task of producing and distributing documentaries for a global television audience that much more complex. Besides differing on an assortment of technical specifications, nations also differ in how they allocate the broadcast spectrum among competing applications, including standard definition, high definition, data services, radio and other communication services.

Developed in the U.S., the ATSC (Advanced Television Standards Committee) 60 Hz system is designed to deliver either a single HD signal or several standard definition digital television signals plus data services within a given channel allotment. atsc nations include the U.S., Canada, Argentina, South Korea, Taiwan and others. Many nations in Central and South America, as well as Asia (including China) are currently testing and evaluating it.

In the European Union, the DVB-T (Digital Video Broadcasting – Terrestrial) is the exclusive digital broadcasting system. Even though a standard for HDTV has been developed for the DVB system (1250/50), it appears that DVB is geared primarily to standard def rather than HD television.

EU broadcasters would have to overcome major hurdles to successfully launch HD, according to ATSC executive director Craig Tanner. ‘Under DVB, broadcasters are only allotted single, standard definition channels, which lack the bandwidth for HD broadcasting. As things stand now, to broadcast a high def program a broadcaster would have to convince three of his competitors to go black for the duration of the program. That’s unlikely to happen in today’s competitive marketplace.’

Another drawback is the fact that the digital receivers being sold in Europe are not HD compatible. That means that everyone who put down big bucks to be among the first to go digital would have to do it again for an HD-compatible set. Tanner postulates that, because most people keep their TV sets for at least five years, those who recently bought digital receivers would be unlikely to buy new sets again so soon, even to go HD-compatible.

Not surprisingly, DVB, with its identical 625 line resolution and 50 Hz frame rate, is often referred to as digital PAL. According to Tanner, however, the designation isn’t accurate. ‘Even though their parameters are identical, it encodes color differently. What DVB delivers is 625 line digital component (YUV), 4:2:2 sampled video, completely different from PAL and PAL+ – the enhanced, 16 x 9 version of analog PAL. PAL+ and 625 line digital were both designed to integrate easily with standard PAL, much more so than with HD broadcasting.’

While DVB currently predominates among EU nations, Australia and New Zealand have also adopted it, with the intention of utilizing it for both HD and SD. If and when they do so, they will be the first DVB adopters to implement HD. It remains to be seen whether they will try to use DVB’s 1250 line hd standard, or incorporate the ATSC’s 1125 line standard. They might even choose the Japanese path, which would be to make their HD standard ATSC compliant.

In fact, the Japanese launched the world’s first successful HD broadcasting service and have developed a unique digital broadcasting system that incorporates HD and multiple SD channels, plus radio, mobile TV and other broadcast spectrum users. Referred to as the ISDB digital broadcasting system, it has been described as a Japanese variation on DVB, yet includes HD and multiple SD channels. Although many of the technical standards for ISDB have not been finalized, the HD standard is expected to be ATSC compliant so that HD programming produced for broadcast in Japan would be available for broadcast within an ATSC system, possibly without the need for any standards conversion.

Inside observers, like New York-based indie producer Barry Rebo, who has been doing HD coproductions with Japanese broadcaster NHK since the late-’80s, believe that the lines of convergence will far exceed those of divergence. ‘The truth is that we can take a tape out of a deck in the U.S., send it to Japan, and they can play it for broadcast from one of their VTRs without any glitches. Most of the HD production equipment we’re using in the U.S. was built to meet Japan’s HD specs, which is why the initial hd cams scanned 1035 horizontal lines, rather than 1080. But, all of that is changing. The Japanese are switching to 1080i now that the equipment is becoming available, just as we are here. The HD manufacturers agreed recently to ship only 1080 line gear from now on – HD cameras, VTRs, switchers etcetera, will be shipped from the same inventory to Japan, the U.S. and elsewhere.’

According to broadcaster Richard Wolfe, president of Hollywood-based Hi-Vision America, ‘The idea is to transcend the differences among competing broadcast systems, videotape formats and manufacturers with a common image format for high definition production. The proposed standard calls for HD comprised of 1080 x 1920 samples scanned at either 50 or 60 Hz,’ he explained. This initiative is appropriately named HD-CIF (HD Common Image Format).

To achieve a common image format, a consortium of the world’s major broadcasting associations is recommending that all HD equipment manufacturers produce for the common standard. An example would be HD cam VTRs which can play and record at the ATSC’s 60 Hz frame rate as well as at the 50 Hz rate for DVB. If they succeed, this could make it considerably easier for nations using the DVB system to purchase equipment economically, since hypothetically it would be the same equipment supplied to ATSC users. This would also accommodate the seamless exchange of HD tapes recorded at 50 and 60 Hz, without having to undergo the standards conversion that could cause artifacts and quality loss. In short, it would be a revolutionary development which would make life and business easier and more economical for those producing and distributing HD docs, and hopefully reducing the number of pricey VTRs needed by those who make and distribute on HD videotape.

However, there may also be some underlying reluctance within DVB broadcasting circles to subscribe to an initiative like HD-CIF. According to Wolfe: ‘Europeans have long been wary of becoming swamped with American programming, and have always thrown up technical and other barriers to it. Also, for a long time they’ve enjoyed a technological edge over North America with the pal system, and many feel that they were down-converting when dubbing to ntsc. They may be feeling more defensive than cooperative.’

Mandalay producer Barry Clark echoes a similar perspective on possible European reluctance. ‘For years, Europe enjoyed a superior broadcasting system. This led to arrogance among many European producers, which continues into the present.

‘In terms of HDTV, the ATSC has developed a high technical standard which can work well across the globe, and is likely to be the dominant standard. If that happens, American broadcasters will be able to urge – and even insist – that all producers and distributors deliver programs according to ATSC specifications. The writing is on the wall for those who want to play in the HD arena: Deliver in 1080i, or else. Post houses in Europe know this and are beginning to offer off-line and on-line services in 1080i, which says something.’

Clark believes that progressive European producers will find it safer, more efficient and economical to produce in 1080i than in 625/50. ‘If you produce in 1080, then down-converting to 580 (625) is easy and not too expensive. Trying to up-convert from to 1080 can be a challenge with an uncertain outcome. Also, you can’t add information after the fact,’ he said. Producing in 1250/50 HD could prove much tougher, if not impossible, according to Richard Wolfe: ‘High definition in the DVB world is a myth. It only exists on paper.’

The Origin of Species: Survival of the footage

Progress towards a universal video format for HDTV production and distribution is cold comfort to an industry which is still largely film-based, and which would prefer to remain so. It is still the fervent hope of many in the natural history/science genre that shooting on 16mm film, notably Super 16, may still provide a viable pathway to HD production for global broadcast. The advent of fine-grained Vision film stocks by Kodak, and the refinement of telecine technology, have combined to improve the quality of HD derived from Super 16. Many would argue that they have at least brought Super 16 out of the cold and to the broadcast-quality threshold for HDTV. For those with substantial 16mm film and equipment stockpiles, these encouraging developments are uplifting.

Based on the bottom line, there is an obvious reason for filmmakers to originate on Super 16 for HDTV, rather than 35mm, and its advantages over hd video for acquisition are well known to film shooters like Reinard Radke, a natural history editor for ZDF in Germany. ‘You really need film for slow motion, time lapse and for rugged and extreme conditions, where video cameras may not hold up as well, and where weight is an issue. Of course, the best way to get the film look is to shoot film. For film shooters, the Super 16/standard 16 cameras also start faster than video cameras, and don’t require as much battery power, which makes a big difference when shooting in remote locations.’

Super 16 and 35mm have been referred to as format independent, meaning that they can be mastered from or to any HD video format today or in the future. It is not surprising, therefore, that in this era of blitzkrieg change, Super 16 and 35mm offer a measure of reprieve from the maelstrom of revolving video formats. As Janet Anderson, professional imaging specialist at Eastman Kodak put it at the RealScreen Summit: ’16mm film has been an industry standard for at least 70 years – since before television began. If that isn’t a universal and enduring standard, I don’t know what is. Film also gives producers the ability to upgrade for the price of a can of film, unlike video where you need to buy a whole new expensive camera.’

Of course, film’s detractors question whether Super 16 passes technical muster for widespread HD broadcast applications. A series of microdensitometer tests conducted by CBS in 1996 sought to evaluate 7248 film stock transferred to 1080i using the Philips Spirit Data Cine. Unfortunately for its proponents, the performance of Super 16 fell below the mark, far below either 35mm or HD video.

In terms of sharpness, Super 16′s signal to noise ratio was only 42 dB versus 48 for 35mm film, and 54 dB for HD video. When compared to 35mm (5248) film stock and HD video at 600-800 TV lines (of horizontal resolution/picture height), its responsiveness was 50% lower than that of 35mm film or HD video. Furthermore, when blind-tested, people consistently identified subjects transferred from Super 16 to HD as noticeably softer than those transferred from 35mm or from HD video. According to cbs vice president of technology, Bob Seidel, who co-designed the evaluation, ‘the tests were very straightforward, objective and used easily measured parameters. Super 16 did quite well in the standard definition range of 300 to 400 lines per picture height, but dropped off significantly beyond 500 lines, due to missing details and increasing noise.’

Even though Super 16 film stocks and telecines have improved somewhat since then, Seidel doubts whether this would affect the outcome significantly. ‘It’s a question of how much information you capture to start with. With Super 16, there simply isn’t enough. When resolved for HD, all of the minor flaws which escape notice in standard def, become quite noticeable and register as noise. When you compress the signal many times for broadcast, the flaws become painfully obvious.’

Despite CBS’ dim view of Super 16, its devotees have remained cautiously optimistic about its viability for current and future HD applications, especially as film stocks and telecine technology improve. Some experiments currently underway may offer a practical perspective on the broadcast quality of carefully-shot and deftly-transferred Super 16.

One example involves the transfer of a 60-minute program (Tundra Hunters, produced by Scandinature) from Super 16 to HD by NHK, using Sony’s new digital telecine, the FVS 1000. The 1000 has much better exposure and motion control, but Scandinature is at a disadvantage in that the HD version is being undertaken after the fact.

According to Landin: ‘NHK never expressed an interest in making an HD version until after the program had been shot completely. We’re striking a separate interpositive for the HD version, but they’re cutting and transferring it to HD and then doing the on-line editing. They’re paying all of the costs, so budget wasn’t an issue. We’re holding our breath to see how it works out, since we didn’t shoot Tundra Hunters with high definition in mind, and it has plenty of wide shots. It’s an experiment for both of us. If the HD version doesn’t meet their technical criteria for HDTV then they’ll run it on standard TV.’

NHK is also transferring an entire series, Wild Asia, currently being shot in Super 16 by TVNZ’s Natural History Unit. Explains Neil Harraway, TVNZ’s head of production: ‘They said that having a series of HD films shot on Super 16 was a first for them. A year ago they wouldn’t touch anything shot on Super 16. Maybe the new telecines and vision film stocks, and our expertise and working relationship convinced them to give it a try. The Asian subject matter didn’t hurt either. They will be shooting one of the ten programs in Japan on the HD cam format.’

Even in Europe, there has been some successful experimentation producing HD programs from Super 16. ‘We shot a special on a river in Slovenia, mainly in Super 16, but with some 35mm for HD, and it looked great,’ related Walter Koehler, head of natural history at ORF, Austria. ‘Many people thought it was shot entirely in 35, and couldn’t tell the 35mm shots from the Super 16. The skill and technique of the cameraman in getting the most out of Super 16 and from his equipment makes a huge difference. We still shoot 35mm whenever the budget allows, to be really future-proof. But, we also use it for panoramas to intercut with Super 16. We’re slowly proving to ourselves that Super 16 can work for HDTV.’

Barring an imminent global agreement on a videotape-based HD-CIF, ongoing experiments with Super 16 mixed judiciously with 35mm, and utilizing the latest in film and telecine technology, may enable Super 16 to carve an important niche for itself as a universal origination format. Super 16 critics question its viability for HDTV in the long term, but might have to admit that it does have a role to play in documentaries, particularly in the natural history genre.

Solutions don’t seem to be readily forthcoming, and the debate over a format-independent common origination format for HDTV documentaries and universal HD video formats and broadcast systems appears as though it may rage on for a while.

Glossary of Terms

ATSC Advanced Television Standards Committee

DVB-T Digital Video Broadcasting – Terrestrial

HD-CIF High Density – Common Image Format

PAL Phase Alternating Line

NTSC National Television Systems Committee

VTR Video Tape Recorder

About The Author
Daniele Alcinii is a news reporter at realscreen, the leading international publisher of non-fiction film and television industry news and content. He joins the rs team with journalism experience following a stint out west with Sun Media in Edmonton's Capital Region, and communications work in Melbourne, Australia and Toronto. You can follow him on Twitter at @danielealcinii.