Sports broadcasts demonstrate power of UHD

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    Ericsson, BT Sport, BT Media & Broadcast, Sony, Newtec and Intelsat recently cooperated to demonstrate the power of Ultra HD, transmitting live rugby from the UK to the RAI exhibition centre in Amsterdam during IBC, highlighting how exciting the new format is but also illustrating that Pay TV platforms can start experimenting with UHD immediately using current MPEG-4 AVC compression.

    The Saracens versus Gloucester Aviva Premiership rugby match was broadcast live from Allianz Park in North London to the RAI on Sunday, September 15. This was the first time that a full multi-camera production of a sports event has been captured in 4K UHDTV and transmitted live internationally via satellite and fibre. BT captured the match using three 4K UHDTV Sony cameras and mixers. The Ericsson AVP 2000 contribution encoders and RX8200 professional receivers encoded and decoded the four 3G-SDI feeds in real-time using MPEG-4 AVC (H.264 compression).

    The compressed signal was transmitted as a 100 Mbps video by BT’s outside broadcast unit over the BT Global Media Network to Intelsat, via the Intelsat point of presence at BT Telehouse West, in London. The signal was carried on the IntelsatOne terrestrial network to Intelsat’s teleport in Germany, where it was uplinked to Intelsat 1W, Intelsat’s leading cable and DTH video neighbourhood in Europe, using Newtec’s M6100 satellite modulator. The resulting 4:2:2, 10-bit, 4K UHDTV signal, running at 60 frames per second, was displayed on the Intelsat, Ericsson and Sony booths.

    “Sports is the killer content for UHD – no doubt about that,” declared Dr Giles Wilson, Head of TV Compression at Ericsson. “It is a fundamentally better viewing experience. It is not just about the extra resolution but the sense you get of being there.”

    Wilson notes that the higher resolution (four times HD) is only one aspect to be considered when using the new format. The larger screen sizes also require a higher frame rate to compensate for the extra distance on the screen that movements will cover between frames. To avoid the video looking ‘jerky’ the frame rates need to be increased, starting at double what you get with HD (so 50/60 fps progressive). Wilson says some people will want to go up to 100 or 120 frames per second.

    The 10bit colour depth provides more accurate colour reproduction and Wilson says there is little cost in terms of compressed bandwidth for using 10bit rather than 8bit. The company is also looking to exploit the improved dynamic range, and therefore more detailed contrast, that is possible on modern screens by putting more information into the encoded streams.

    Ericsson has been involved in a number of UHD tests and trials this year and the company has been gathering a lot of data about what works, or does not work, in this format. In terms of creatives, one of the lessons is the need to shoot UHD differently to HDTV. Fast camera movements do not work when viewing on a very large TV . You also need to give the audience a chance to look around the entirety of the screen to see the additional detail that UHD provides, which means holding shots for longer.

    The bottom line, according to Ericsson, is that a bigger screen size gives a bigger experience, although the company is confident that UHD will be a worthwhile experience on smaller screen sizes, like 50 inches. Producers will need to use filming techniques that are acceptable on a smaller screen but look better on the biggest screens, which could mean keeping the core action near the centre of the picture.

    A second IBC demonstration (also shown on the Ericsson and Intelsat booths) showed Manchester United versus Seville in a pre-season friendly, a football match shot at Old Trafford stadium in Manchester as a ‘rehearsal’ UHD shoot. This was transmitted to the RAI as a linear feed of the recorded footage.

    The game was filmed as four HD feeds, each of which made up one quadrant of the eventual UHD output on an 82 inch screen, fed into the TV with four HDMI 1.4 cables. It was encoded in MPEG-4 AVC at 60 frames per second in 4:2:2 with 10bit processing. Ericsson can use its SimulSync technology, developed for 3DTV to synchronize simultaneous left and right eye contribution feeds, to deliver perfect synchronization in a quad-HD scenario.

    An important point to this demonstration was that UHD can be delivered today using the current HDTV infrastructure. “This is a quick win for our customers because they can deploy on their current HD systems to start transmitting 4K to build momentum for the format and learn how to film in UHD,” Fabio Murra, Head of TV Portfolio Marketing, Compression, at Ericsson pointed out.

    It is worth emphasizing that this football and the live rugby were used to show UHD as a concept; they were not a demonstration of HEVC encoding. Ultra HD uses four times the resolution of HDTV, meaning broadcasters have to dedicate at least four times the bandwidth to UHD using MPEG-4 AVC compression. This is acceptable for trials but the industry needs the additional 25-50% compression efficiencies that come with the HEVC/H.265 next generation codec before UHD can become a mass-market commercial proposition.

    Compression vendors are talking about 25-30% efficiency improvements in the first generation HEVC encoders/decoders, rising to 50% over time.  As we reported previously, Carl Furgusson, Head of Business Development, TV Compression at Ericsson, predicts that first generation real-time HEVC encoders will deliver UHD at 15-36Mbps. By the second generation bandwidth demands will be down to 10-24Mbps for live broadcast content. (On-demand content will need less because you can take longer to encode it, using non real-time encoding).

    Ericsson is predicting that the complete ecosystem needed for UHD, from camera lens to television screen, will be ready to support meaningful deployments of television services during 2015.

    We reported previously (in our IBC round-up) how the Manchester United game demonstrated the brilliant detail and colour of UHD, but what stood out was the extent to which UHD on an 82 inch television makes you feel like you are at the football ground. The camera position was in the upper tier in one of the corners of the stadium, so as the game moved towards the faraway goal, you could see the fans below and around you, the whole pitch and all 22 players, just as you do when watching in a stadium. The phrase that everyone uses when talking about UHD is ‘immersive experience’ and that is what makes this format different – it is not just about a better looking picture.

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