special report ibc 2012
very basic concept is that of the 'asset' which consists simply of the full-res media file and an XML which contains the metadata. This XML is just a simple text file that contains keywords against specific tags, so it can be transferred into any system, including Final Cut Server, CatDV, IP Director or any future data base with a simple script that could conform it to the new database requirements."
4K programme transmission
ATEME (France) chief technical officer, Pierre Larbier, addressed the practicalities of 4K television broadcasting: "Deployment of 4K to the home is only possible if the compressed bit-rate is compatible with the existing distribution architecture. The maximum available bit-rate for a single channel on DTT, satellite or cable distribution networks is between 24 and 45 megabits per second. HD channels that are broadcast using the H.264/AVC (6) video compression standard are encoded at bitrates ranging from about 5 to 10 megabits per second. This enables between three and eight HD channels per satellite transponder or QAM. Since 4K TV requires eight
Figure 4: Elements of NDS Project Fresco titled
television system.
Second- screen issues formed a substantial element of IBC2012 given the rapidly expanding use of
smartphones and iPads.
times more pixels to process and transmit than 1080i, one could think that it would require eight times more bit-rate. If this were the case, it would be almost impossible to fit a single 4K TV channel on a transponder with a video quality compliant to broadcast standards. Fortunately, an equivalent perceived video quality is achieved at a much lower bit-rate than could be guessed by the pixel count ratio. For instance, good quality is obtained in SD at about 2Mbits/s while HD requires only about 6Mbits/s. The bit- rate ratio is three but the pixel count ratio is five (in 25 Hz interlaced systems). To verify the bit-rate ratios applicable between 4K and HD, we encoded in H.264/AVC a test sequence acquired natively in 4K at 50 Hz from a RED Epic camera. This sequence was downscaled to 1080p50 and 720p50 and we measured the bit-rate to reach the same objective video quality. It is interesting to note that, like in the SD vs HD case, the required bit-rate to obtain the same quality is much lower than anticipated: less than 20Mbits/s are needed to match the 720p video quality PSNR metric. This suggests that a single channel could be transmitted on a DVB-T transponder and two channels can easily fit using 45MBps-QAM modulation, all using just H.264/AVC compression. One valuable advantage of using H.264/AVC is the announced availability of chips able to decode 4K TV formats. This is the case, for instance, with the Intel Ivy-Bridge family of processors."
Super Hi-Vision (8K) codec development
Figure 5:
Fraunhofer 3D surround projection.
NHK continued its efforts to promote Super Hi-Vision (SHV) as a credible television production and transmission platform. N. Nakajima and colleagues
from the broadcaster's science and technology laboratories in Tokyo outlined the development of a real- time SHV video codec: "In April 2012, NHK conducted an international transmission experiment over a global shared IP network which relay on multi-domain research networks with a third-generation video codec system. In this experiment, the SHV signal was compressed to a 280 megabits per second bit-rate, converted to an IP stream and then transmitted from London to five reception points. The transmitting point was the BBC Television Centre in London. The five reception points were in London, Bradford, Glasgow, Washington DC, NHK STRL (Tokyo) and from there to the NHK Broadcasting Centre (Tokyo) (Figure 3). We were able to receive SHV signals and show good quality SHV images at each reception point. Furthermore, we succeeded in achieving stable reception for more than two days in this experiment. No errors were detected by the equipment and no noise occurred in the decoded images. This experiment demonstrated that it is possible to transmit SHV signals with a large amount of data to many reception points in real time. The success of this international transmission experiment is a further step toward achieving SHV broadcasting scheduled for 2020."
Tileable television display
Alex Ashley and colleagues from NDS outlined a tileable display technology called Project Fresco (Figure 4): "Our vision of the future is a viewing environment with large displays constructed from modular tiles. These displays are frameless, unobtrusive, ultra high-definition and ambient. They can be adapted to fill or partially fill one or more walls of a room, and will co-operate to provide an integrated experience. A client device is connected to one or more tiles, and is responsible for rendering content for the tiles connected to it. The client device selects only the media components that are to be shown on its connected tiles - this is a well- known technique in computer graphics referred to as culling or clipping. This approach means that each client only needs sufficient hardware to perform media decoding and graphics rendering for the tiles it supports. The layout engine is a software component that can be located in a client device, a home gateway or
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www.ibeweb.com
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