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Personal Video Recorders
Technology
Like a VCR, a Personal Video Recorder (PVR, also known
as DVR, Digital Video Recorder) allows a person to record a TV signal,
to be watched later. However unlike a VCR, the storage medium is a digital
hard drive rather than analog magnetic tape. This offers two advantages:
undiminished quality of recording, and random access. PVRs are also
connected devices, using the phone line to coordinate with a central
server to control recording times. This allows a user to fully control
the device with one onscreen interface.
Undiminished Quality
Digital recorders such as PVRs convert sound and/or
video into a digital file. This has the double advantage of better
preserving the quality of the original signal, and of creating a file
that will not lose quality with subsequent viewings.
As with all video and audio storage, the quality of
a recording and its maximum recordable length are inversely related.
On a PVR, like a VCR, the quality of recording can be controlled by
users, but greater quality recording results in larger files, limiting
the amount that can be saved. The highest quality setting on a PVR
results in a better recording than is capable than on a VCR, although
they are not designed to record at HDTV levels of resolution. Unlike
a VCR, PVRs are available in a variety of capacities. Currently the
best can record up to 60 hours of programming, but the limiting factor
on storage capacity is cost, not technology.
Random Access
VCR tapes record sequentially, and cannot be played
while recording. Digital files can be accessed at any point at any
time, allowing a PVR to provide services that a VCR cannot, in addition
to the standard VCR commands of record, play, fast forward, etc. Since
the TV signal passes through the PVR before being displayed, the PVR
is set to record with a constant 7 to 8 second delay, allowing a user
to pause a live show, resume watching later, fast forward to catch
up with real time, or even rewind to see the last 7 or 8 seconds (depending
on the service) again. Furthermore, PVRs are not limited by mechanical
tape speeds, and so can fast forward and rewind at tremendous speeds,
or even jump around between recordings instantaneously. To put it
in context, the difference in capability between a VCR and PVR is
roughly analogous to the difference between an audio tape player and
a CD or MP3 player.
Connected services
PVRs are connected to a central server, making contact
via phone line once a day to download TV schedule information. Because
of this, a user can program the device to record shows with a simple
onscreen graphic interface (ie point and click). A user can also specify
a show or type of show for the device to record automatically every
time it comes on. It's also possible for some devices to track a user's
preferences while they are watching shows, and develop a profile to
use for automatically recording shows the user may like.
Service providers:*
TiVo
- Cost: $10 per month, or $200 lifetime (lifetime of set top box)
- PVR also available bundled with DirecTV receiver
ReplayTV
- Cost of service is included in retail price of device
- No monthly fee
Microsoft UltimateTV
- Requires DirecTV satellite TV subscription
- Cost: $10 per month (UltimateTV), $21.99 per month (DirecTV)
- can also provide interactive TV and Internet access
DirecTV
- Satellite-based digital TV provider
- Cost: Starts at $21.99 per month
Manufacturers:*
Panasonic
- 20 to 60 hour capacity
- $400 to $800
- Stand alone PVR or integrated with television
- Provider: ReplayTV
Phillips
Electronics
- 20 to 60 hour capacity
- $200 to $600
- Stand alone PVR or integrated with satellite receiver
- Provider: TiVo
Sony
- 30 to 35 hour capacity
- $400
- Stand alone PVR or integrated with satellite receiver
- Provider: TiVo or UltimateTV
RCA
- 35 hour capacity
- $400
- Integrated satellite receiver/PVR
- Provider: UltimateTV
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8/2/01 |
