BOOT CAMP 491 (28/08/07)
TV on your PC
For the past twenty or so years the dividing line
between televisions and PCs has been getting narrower; in some respects it has
disappeared altogether. In fact the ‘digitisation’ of television goes way back,
to 1972 when the BBC started the first regular Teletext broadcasts, sending
hundreds of ‘pages’ of news and information in the form of digital data, hidden
inside unused portions of the analogue TV signal. The next major milestone was
in 1982 when the BBC, once again, pioneered digital stereo sound with its
groundbreaking NICAM system and digital television. Full-blown digital
television finally became a reality on October 1st 1998 when the Sky Digital
satellite broadcasting service was launched.
From the late 70s onwards much of the circuitry
involved in tuning, picture adjustment, video and audio processing and remote
control, was handled by digital microchips, and more recently microcontrollers
and microprocessors, which are close relatives of the CPU chips used in PCs.
Nowadays almost the entire broadcasting chain, from
the TV studio to the screens in your home (and pockets), is in the digital
domain, irrespective of whether the signal comes via a roof or set top aerial,
satellite dish, cable, telephone line or mobile phone, and in five years the
process will be complete, following the switch-off of the analogue transmitter
network
Many of the devices in the shops described as TVs are
in fact little more than computers, configured to receive television
broadcasts. However, whilst television have been metamorphosing into PCs it’s
only in the last ten years that computers been able to display TV pictures, but
they’re catching up fast.
Analogue TV tuner cards have been around since the
mid 1990’s but almost without exception the early ones were difficult to
install and setup. One of the first concerted attempts to integrate television
and computer technologies came about in 1995 when Olivetti introduced the
Envision PC. This was a Pentium 486 machine operating at 75MHz, running Windows
95. It was dressed up to look like a VCR and it had a built in tuner, a CD
drive that could play now defunct Video CD discs but the key feature was a
SCART socket that meant it could be connected to an ordinary TV, rather than a
PC monitor. Unfortunately it was badly designed, riddled with bugs, overpriced,
poorly marketed so not surprisingly it disappeared -- almost without trace --
after just a year or so.
The situation improved slightly with the introduction
of Windows 98 with more advanced video capabilities and greater stability, this
also coincided with rapid increases in PC processor speed, cheaper memory and
larger hard disc drives. For the first time TV tuner cards became a practical proposition
and it was just about possible to watch terrestrial television broadcasts on a
small inset window on your monitor screen whilst running another program, like
a word processor. It was all still a bit hit and miss, though, and it pushed
the technology to its limits so more often than not Windows would crash under
the strain.
The marriage between TVs and computers – in the UK at
least -- was consummated in 2002 following the launches of Windows XP and
Freeview, the terrestrial digital TV service resurrected from the ashes of the
failed OnDigital system.
Windows XP’s contribution was speed, stability,
vastly improved multimedia capabilities and (mostly) effortless connectivity to
peripheral devices whilst Freeview delivers a subscription-free, multi-channel
digital TV service that now reaches more than 98 percent of the UK population.
Freeview and other digital television services, like BSKYB and cable make
everything so much easier for the simple reason that computers are digital
devices. Most of the problems associated with first generation TV adaptors lay
with the analogue to digital conversion process, and the inherent differences
between a 625-line television picture and the hybrid (analogue and digital) and
digital display systems used by desktop and laptop PCs.
The upshot of all this is a clever little gadget
called a USB digital TV/Freeview receiver; they look like fat memory sticks and
typically costs around Ł30. These devices turn your desktop PC or laptop into a
fully-fledged TV, capable of receiving more than 30 TV channels and over 20
radio stations, provided of course digital TV reception is possible where you
are. (they usually come with a portable antenna but they work best with a good
signal, preferably from a rooftop aerial).
Most of them also come with software that lets you
record TV and radio programmes, just like a VCR or PVR, use the Electronic
Programme Guide (EPG) to time-shift programmes, plus they can do clever tricks
like ‘pausing’ live TV. Several models have dual tuners, so you can watch one
channel whilst recording another, and there’s no need to worry about squinting
at a titchy monitor screen – see this week’s Top Tip
Recordings are stored on the PC’s hard disc drive so
you will need plenty of free space if you want to do a lot of recording, but
the point is, for a relatively small outlay, and a fraction of the cost of a
digital video recorder you can turn your computer into a fully fledged
multimedia device.
Next Week – Vista Tuning Tips
JARGON FILTER
NICAM
Near
instantaneously Companded Audio Multiplex, digital stereo TV sound system,
developed by the BBC and widely used in many other countries
PAUSE LIVE TV
A facility on
many hard drive-based digital video recorders whereby the selected TV channel
is continuously recorded, allowing the ‘live’ program to be frozen, and
subsequently replayed from the stored data
PVR
Personal
Video Recorder – typically a video recording device that stores TV programmes
on a hard disc drive (as opposed to tape or DVDs)
TOP TIP
Many laptops have
‘composite’ and ‘S-Video’ video output sockets that can be connected directly
to a normal TV; the PC’s audio output connects to the TV’s ‘line’ input socket,
so you can listen to the TV channel through the TV’s built-in speakers. Additionally
most LCD and plasma flat screen TVs have ‘VGA’ input sockets so they can be
connected to a PC or laptop in place of a normal monitor.
Don't forget, there's a
full archive of previous Boot Camp Top Tips at www.pctoptips.co.uk
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© R. Maybury 2007, 2108
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