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by David Fox
High definition is rapidly becoming the norm for high-end facilities in the US. In Europe, the move to HD is slower, but heading in the same direction.
Because 525 lines TV doesn't look good on large TV screens, the demand for HD is mainly from NTSC countries, which includes two important markets, the US and Japan. For the BBC, which obtained 70% of the funding for its £10 million 2002 wildlife series, Blue Planet, from overseas, the ability to deliver in HD is increasingly important.
BBC Bristol, the home of the natural history unit, has HD post-production, including Flame and Fire, which has to be able to cope with any format, not just 1080-line material at 24, 25 and 30 frames per second progressive and 50 or 60 fields interlaced, but also upconverting from a wide range of other formats.
"Early upconversions were poor," says BBC Resources' technical development manager, Andy King, partly because most of them were from 525 rather than 625, but "the technology has improved."
For Blue Planet, which was shot over a number of years, where shooting HD would have been prohibitively expensive, King didn't think upconversion could work, not that anyone had predicted that an HD version would be needed. However, after it was transmitted, KBS Korea wanted it in HD, so it was upconverted using motion interpolation. "The recipients loved it and the Americans have loved it as well," he says. The BBC is now looking at upconverting a further 180 hours of programming.
However, not every programme is suitable for upconversion. "Any artifact you have on your picture at SD will be magnified when you take it to HD," says King. It works best where material was shot 16:9 (film or video), there is minimal archive content, and programmes that have not been processed too much. It won't work if there is a lot of 4:3 archive footage, material shot on single-chip DV material (although some bright, daytime DV shots can work), or if you use compressed editing systems or have heavy graphics content (with tracking and stabilisation or artificially sharpened material), although in recent tests CGI seems to stand up to it better than expected. "Aperture correction seems to be the killer at the moment," he says.
On Blue Planet, the BBC worked uncompressed in post and there was a lot of newly shot material. It also helped that so much material was shot underwater, as the water "filters out many upconversion artifacts," he says.
The US distributors initially said they didn't want upconverted programming, but when they were shown episode four of Blue Planet they thought it had been shot on HD. If doing work for the US or Japan, he advises to show them your results now and they might be happy with lower resolution material, which will save a lot of time in rendering.
King believes that it is best to shoot at 25 fps, because it is easier to to post in Europe on standard equipment, then just slow it down for delivery to film and for use in NTSC countries at 24 fps. If going for international sales, King advises to check the delivery format. Even where it is agreed in advance, that can change. Great Natural Wonders, was shot on film and transferred to HD as it was a Japanese co-production. It was shot at 50i, but speeded up to 59.94 at the last minute for Japan, which was OK as the Japanese had a lot of other material to put in. It is easy to change speeds with frame-based, progressive material than interlaced, which is why he believes that 25fps is the most sensible compromise for the BBC.
Even some news stories may need to be delivered in HD. When the BBC covered the Dali Lama's visit to Belfast, CBS wanted to show it in HD. The end result was one-third shot on HDCAM 1920x1080, one-third shot on the earlier Sony 700 HDCAM at 1920x1035 (not all HDCAM is the same). The rest was shot on Digital Betacam, 720x576 and upconverted, although it has the wrong field rate King believes they got away with it because there wasn't much movement in the picture.
It is now (mid 2002) experimenting with Panasonic's HD-DVCPRO variable frame rate camera, because so much natural history is shot at 60 fps and replayed at 25 fps, which can't normally be done on video. King also likes its low-light performance. It is also about to do some 3D HD stereoscopic animation, which takes more time as it has twice as many video layers.
Indeed, because the HD frame is six times bigger than an SD frame, it takes longer to render, which can make working nonlinear frustrating. "Because of the extra time it takes, some clients are not prepared to wait for perfection," he says.
About a year ago, The Farm Group, opened a separate HD facility, Home, in central London. "I wouldn't like to add HD to an existing SD facility," because there are too many conflicts with cabling and references, says its technical director, David Klafkowski. "It is easier to pull it out and do it all again."
It would have been possible to update The Farm to HD, as it was fairly new, but there wouldn't have been enough room in the cable runs to add HD cabling, nor would there have been enough room to add HD monitors or vectorscopes.
Facilities could just add an HD|DS as a stand-alone suite, but it wouldn't be easy to integrate it, and "you need to have all the kit to deliver complete HD programmes," he says.
Home has an HD Spirit and HD|DS, which it chose because it already had experienced DS operators, and this was "a natural progression." It also has a linear suite that will work in any format, with HDCAM and HD-D5 VCRs, a Snell & Wilcox HD 1024 vision mixer, and two Sierra QuickFrame HD disk drives, which can store up to 90 minutes each, for non-compressed disk-to-disk work.
Klafkowski feels that the biggest difficulty is ensuring you know the right delivery format and who is the primary broadcaster, because of problems with audio when you slow down material captured at 25 frames per second, "so decide who is the final market first."
There is also the difference in look between interlaced and progressive. While Europeans tend to prefer HD to look like film, "the Japanese like it to look like video on steroids."
Home worked on the BBC/Sony Columbia Tristar 2002 co-production, Rockface, a mountain rescue drama series shot on HDCAM at 25 fps, which will be slowed down to 24p for the US.
It also did the deliverables of Band Of Brothers in all variants of HD for HBO, which didn't want a 24fps master, but 59.94. It also did the speed ups for 50i for Australia and for the 625-line version for the BBC. It has done a lot of European-originated programming for NHK and a couple of feature films for HD delivery.
When M2 chairman, Bill Cullen, looked at HD a year ago, he thought it was still too costly for what his clients were willing to pay. "The few that were willing to pay anything extra would only want to pay a very small premium."
Although the cost of HD production "is coming down to a realistic level," post-production equipment is still expensive, especially HD VCRs and monitors, although systems such as HD|DS and 5D's CyborgM (which M2 has just installed) are more reasonably priced.
"There is a limited market for HD in Europe at the moment, but we expect that to change," not necessarily immediately, but when it does it will grow exponentially.
At present, "the whole of production and post-production is about future proofing or going back to film or large screen presentations rather than HD transmission, at least in Europe," he adds.
M2 is a large, established standard definition facility, and they wanted to integrate HD into it, which means they have to be able to do SD work on whatever systems they buy. This is why it chose the CyborgM HD, a new rival for Flame, Henry and Inferno. It can take in any file format and can go up to 6K film. "It's main power is all the different effects you can do on it. It's got a fairly intuitive interface." It also has an "amazing slo-mo device", time twister, which interpolates additional pixels for inbetween shots "It's very, very clever," he says. It runs on NT, with some dedicated i/o hardware, and is integrated with rest of facility on the SD side, but stands alone for HD.
Cullen is seeing the middle ground of post-production disappearing. "If you want to do it really well, you will have to do it in HD," but "I think it is going to be a slow process, predominately to do with the cost," he says.
Klafkowski has noticed that US facilities are now getting no more for HD work than they used to get for SD, but that the prices they can charge for SD have dropped.
"Discovery has said that in two years time it won't pay any more for HD than it currently pays for SD," adds Cullen.
Home currently charges about 30% more for HD because the equipment costs 30% more, but that will change. "It's not the equipment, but the people that matter. Ultimately, it doesn't really matter how much the equipment costs," says Klafkowski.
He believes the next big incentive to go HD will be the arrival of HD DVD over the next couple of years, which will open up a new outlet for productions, especially in Europe, and offer new competition for broadcasters.