Broadcaster Magazine

BBC’s ‘The Blue Planet’ goes high definition

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  • The stunning images in the BBC’s acclaimed ‘The Blue Planet’ natural history series have been dramatically improved by the BBC’s conversion of the series to high definition for international distribution. The upconversion from standard definition was carried out using Alchemist Platinum, the latest generation of the motion compensated converter from Snell & Wilcox.

    Narrated by Sir David Attenborough, The Blue Planet, a £7 million U.K. (or approximately $10 million U.S.) co-production for the BBC, is an epic eight-part series exploring the wonders of the earth’s oceans and its inhabitants. It first airs in the U.S. on the Discovery Network on January 27th.

    KBS (Korean Broadcasting Services) had already purchased the series in standard resolution, but recently requested that it be delivered in high definition as well.

    The program production involved more than 40 film crews over the course of five years, often working in some of the most inhospitable terrain on land or under sea.

    The source material varied from a wide range of film and video formats — including frame and field-based animation. Because of the number of crews involved, it was impossible to determine the technical specifications of each piece of footage.

    The wide range of format input presented a problem, because while many format converters can work well with a single format (for example, film), they are not designed to handle mixed media material.

    According to BBC resources’ technology development manager, Andy King, who was responsible for the HD conversion: “Wildlife programs are traditionally shot on film, with much material acquired at upwards of 40 frames per second in order to capture motion and detail correctly. This tends to give a slight slow motion effect that enables the viewer to see what is going on.

    “However, for many of the underwater sequences it was important to give a sense of speed, so video running at 50i was more appropriate. Shooting video underwater is also easier because the cameras are smaller, and you can spend more time filming before you have to change rolls. Having so much video footage interspersed with the film footage was a change that presented a particular challenge in providing a seamless transfer to HD.”

    King was aware that broadcast manufacturer Snell & Wilcox had recently introduced “Alchemist Platinum”, its new breed of motion-compensated standards converter — with the important option of a high definition output.

    “The motion compensation was of particular importance to us for archive and BBC delivery specifications,” said King. “The series was always going to be mastered at 625/50i. Making the seamless conversion to 1080/59.94i was extremely important, and we are delighted with the results.”

    According to Snell & Wilcox chief technology engineer, Andy Major: “The fact that a significant percentage of the original material was shot on video is very significant to the use of Alchemist Platinum for the HD upconversion.

    There are a number of solutions for upconverting film-based material, but Platinum is the only commercially available product that will perform a true, single-step, motion-compensated upconversion of video with frame rate change. Hence the resulting HD output — of film and/or video — has the added benefit of accurate motion portrayal, as well as high resolution.”

    The video was mastered at BBC Post Production, Bristol, which for quality purposes insists on uncompressed program editing. This results in high quality, noise free, SD masters that will upconvert extremely well.

    The reason for this is that if compressed tape or disk stores are used in the editing process, the process of multiple-compression passes causes artefact build up, which may not be visible in SD, but will be visually unacceptable once the material has been upconverted to HD. In order to maximize the picture quality of any future HD conversion of SD material, it’s important to stay in the uncompressed domain during mastering.

    According to Major: “Alchemist Platinum is essential for converting uncompressed SD material because it is 12-bit, 4:4:4, and ‘transparent’.

    Other converters on the market are only really aimed at ‘format conversion’.

    Format converters work well when there is a no frame rate change involved, or when the material is 100 per cent film-based, but they would have been totally inappropriate for this type of mixed media material.”

    It begs the question: Why not shoot everything in HD to start with?

    Andy King responds: “In a perfect world, that would be ideal, although HD video does not yet give us all the features of film. It’s also not practical because of costs, the extensive use of SD archives in natural history programs, and the difficulty of getting all crews to shoot in the same format. Anybody want to pay for 40 crews to have HD cameras?

    “The answer for the time being is to master in 625/50 standard definition with uncompressed editing tools — then simply upconvert the final program.

    “The work on The Blue Planet has been so successful that we’re now looking at a considerable inventory of programming that would benefit from HD conversion.”