Page 24 - Fujifilm Exposure_4 Samantha Janus_ok

Making Sense Of The “B” Word
Making Sense Of The “B” Word
‘Much is made nowadays in broadcast circles about the decreasing need for tape in post- production and distribution. There are very obvious advantages to removing tape from the television process as much as is possi- ble. Tapeless editing is non-linear and non- linear is cool. Tape costs money, lots of it,
and tape machines cost lots of money to run. Discs are cheap once you’ve bought them and require vir- tually no maintenance once they are installed.
In distribution, digital compression techniques enable very high quality pictures to be sent over satellites or fibre to any part of the world, greatly reducing costs. At the receive station, new server technology records the material directly to disc ready for automated transmission. Even at domestic level, DVD threatens the VHS domination of the mar- ket for the first time in a generation offering immense- ly improved video and audio quality as well as a plat- form for games and interactive entertainment and learning. Surely this adds up to a pretty bleak future for the tape manufacturing business? Yes and no.
The key word to understand in assessing future trends in technology is bandwidth. In the digital world bandwidth describes the amount of data that can be passed at any given moment, normally expressed as bits per second. In layman’s terms, it’s really a bit like plumbing. The bigger the pipe the more fluid can flow through it at any given time. In understanding the implications of bandwidth to the television world we need to get some idea of scale.
When expressed digitally a television picture
uses a very large amount of data relative to other
requires a monstrous 75 gygabytes of storage. To put this in perspective, a television circuit requires the bandwidth of over twenty thousand telephone con- versations and would need four thousand ISDN lines to carry it in real time. Quite a task. Worse still, because this data contains sychronising information, it must be re-clocked at regular intervals.
Tape on the other hand has very little trouble dealingwiththeselargeamountsofdata. Advanced error correction techniques allow this data to be retrieved without loss and of course storage is per- manentandnon-volatile. Furthermorethenewtele- vision standards of higher definitions will necessitate the use of tape as a storage mechanism. The data rates necessary to store un-compressed digital high definition pictures and sound make the use of disc prohibitive. Similarly, the length of time required to transmit the data over fibre or digital satellite would make the process uneconomic. Tape is, and will con- tinue to be for some time to come, the preferred method for the distribution of un-compressed high definition television.
In a modern facility we have to take all of these technologies and bring them together to offer our customers exactly what they need. At TELE-CINE we have over one hundred broadcast quality VTRs work- ing across the complete range of the facility. Tape is very important to us in editing in that it is still the pri- mary way of exporting data to the outside world.
Other methods of distribution and editing are becoming more popular but tape continues to be used and shows no signs of declining. We use a mix- ture of internal and external networks to aid editing and distribution. Inside the facility we can route ana- logue video and audio but predominantly we move pictures and sound around on a 270 Megabit serial digital network. We also have multiple lines to the BT tower in both analogue and digital formats.
More and more of our work is involved in moving pictures as files rather than as streams of integrated digital video. In addition to our BT lines, we are also
connected to the Triumph Colt switch and to an exciting new venture with Canadian communications giant Teleglobe called Millennium. This service will run compressed 8 Megabit or 15 Megabit MPEG 2 files via cable across the Atlantic with connections to ATM clouds across North America. This network is pri- marily designed to offer transmission quality feeds as video but can also be used as the backbone for a new service which we are offering called “File Exchange”.
The basic concept allows the fast transfer of any type of data. We will be able to offer variable bit rate transfer to Los Angeles by April this year at speeds that could allow the mailing of a D1 quality commer- cial door to door between London and LA in less than an hour. Video is stored at full resolution here in London on a computer and is forwarded to a similar computer in our partner’s office in LA. They then reconstitute the file to tape and delivers it directly to the customer. As telecommunications are deregulat- ed in the USA, it will be possible to go door to door to many other points of presence both in Los Angeles and other important hubs.
This technology is exciting but it does not negate the need for tape. Although we at TELE-CINE are trying to move our focus inside and outside the facility towards less reliance on tape, this is primarily designed to increase the efficiency of the operation. In doing this we have seen our demand for tape actu- ally grow as more work comes through the facility which needs archiving. Furthermore tape is still the only reliable medium for long term storage of data.
There are rumours of new tape machines using alternatives to magnetic heads which will record on tape and may offer dramatically increased access speeds over current technology. This will provide
The future for tape in a tapeless world?
applications. Every second of a digital television sig- ’ new challenges to tape manufacturers as their mar-
nal requires 270 million bits of data to describe it. One hour of digital television, uncompressed
kets re-focus rather than disappear. ■ DAVE POLLARD
Photos: Tele-Cine’s Jeff Emerson, Head Of Production and Dave Pollard, Facilities Director
Photos top of page: Stills from Tele-Cine’s recent productions The Phoenix and the Carpet, from the E. Nesbit classic novel and Two Worlds, which explores the world’s oceans.
EXPOSURE • 24 & 25