BOOT CAMP 519 (08/04/08)
Internet TV and BBC iPlayer
the past year or so there has been a minor explosion in the number of
broadcasters using the Internet to distribute TV programmes. Of course there is
nothing new about sending live and recorded video over computer networks and
legend has it the first web TV superstar was actually a coffee pot.
pot in question began its brief career back in 1991, in the Trojan Room of the
Computer Laboratory department at the University of Cambridge. The pot was the
test subject for the trial of the world’s first network camera or webcam the
idea was that coffee drinkers in other parts of the building could keep watch
on it, on their computer screens, to see when a new brew was ready and avoid
wasted journeys. Judging by the quality and content of some Internet TV
services, it has been downhill ever since…
are getting better, though, and now, web TV services like the BBC iPlayer,
which we’ll be taking a close look at over the next couple of weeks, make it
possible to watch mainstream television programmes (and listen to radio
programmes) on your computer the day after they were broadcast, either straight
away, or at your leisure by downloading the program onto your computer, but we
are getting ahead of ourselves so let’s see how it is done.
fact there’s no magic or special tricks involved in sending television
programmes to home computers via the Internet. In essence they are no different
to emails, web pages and music downloads, and they travel around the web as
‘packets’ of data. There’s nothing new
in this but broadband has made it a practical proposition by reducing the
amount of time it takes to send the huge volumes of data involved in television
pictures and sound. Even on a relatively slow broadband systems (512kb/s –
1Mb/s) it is possible to view a ‘streamed’ program in real time, though the
data has to be heavily compressed, to avoid too many interruptions, caused by
the packets not coming down the pipe quickly enough. The data has to be
‘buffered’ by the PC and high levels of compression means that the picture has
to be quite small; it’s good enough to view on a laptop or desktop monitor but
switching to full screen mode reveals the flaws.
want better picture quality, comparable with normal TV and capable of being
viewed on a living room television screen, then you have to download and store
a lot of data on your PC, upwards of 600Mb per hour of programme time.
Depending on your broadband speed a 30-minute TV program, say, could take
anywhere from a few minutes to several hours to download to your computer’s
hard disc drive.
own broadband would not have been enough to make web TV take off as swiftly as
it has. Problems would arise if lots of people all tried to download the same
program at the same time. The server computers where the data is stored and the
data pipelines that connect them to the Internet just couldn’t cope with the
demand. The solution is a clever trick known as peer-to-peer (P2P) network
sharing, which, you may recall was the technology at the centre of the illegal
principle it’s very simple, instead of storing TV programmes only on
centralised server computers, a peer-to-peer network takes advantage of the
fact that soon after its release a programme will be on many thousands of
computers connected to the Internet. So rather than downloading the entire
programme from one location, software on the computer downloads parts of the
programme from many different sources, thus spreading the load and reducing
data bottlenecks, at least that’s the theory, but more about that next week.
final and most contentious pieces in the Internet TV jigsaw are copyright,
licensing and distribution – see also this week’s Top Tip.
take the BBC as an example, nowadays independent producers account for a very
large slice of the corporation’s output, resulting in a tangle of rights; add
to that the complexities of who gets what for showing archived material and
movies and you can begin to appreciate the scale of the problem.
order to get the project off the ground in a timely manner, retain control over
its output and avoid a legal nightmare the BBC had little choice but to use off
the shelf software with built-in Digital Rights Management (DRM) but for
viewers this has several significant drawbacks.
whilst you can watch low grade streamed programs on almost any Windows Mac or
Linux computer with an Internet connection (and iPhones), you can only download
higher quality material on Windows XP and Vista PCs with Windows Media Player,
(v9 or later). The BBC are working on Apple Mac and Linux versions of the
iPlayer Download Manager software, promised for later this year, but don’t hold
your breath. There is a workaround for Linux PCs involving a loophole created
by an Apple iPhone viewer but the BBC are trying to stop it from working.
second consequence of DRM is that downloaded programmes self-destruct after 30
days and you can watch them as often as you like whilst the program is
available for streaming but after that they’re history. Again there are
workarounds but they’re for knowledgeable geeks only.
DRM stops anyone outside the UK viewing or downloading programmes, much to the
annoyance of a great many ex-pats and fans of BBC programmes living overseas.
There are convoluted ways to get around that too but the BBC are trying hard to
keep a lid on it so don’t expect to be watching episodes of East Enders on a
laptop when you are on holiday any time soon.
Next Week – Downloading TV and Video from the Web part 2
in a temporary memory by player software, to minimise interruptions caused by
slow or interrupted Internet connections
configuration where data is stored on and routed by PCs connected to a network,
rather than by a central server
used to send sound and pictures over the Internet for immediate, real-time
one piece of good news concerning Digital Rights Management is that currently
you don’t need a TV licence to watch BBC programs on iPlayer as they are not
‘live’. It would certainly be very difficult for them to administrate but the
BBC has made it clear that as and when later versions of iPlayer are developed
and the service is upgraded to show live programmes then you will need to be a
registered licence holder in order to use it.
Don't forget, there's a
full archive of previous Boot Camp Top Tips at www.pctoptips.co.uk
© R. Maybury 2008, 1903