PNeski wrote:
just wondering ,I saw the d theatre deck dosn't
have analoge in (HDTV)
Generally, all consumer HDTV recording solutions are actually referring
to recording
MPEG2
HDTV signals,
*not*
3 cable component analog HDTV signals.
Typical sources for MPEG2 HDTV video signals are over the air
broadcasts
(ATSC signals). The
Samsung SIR-T165
is an example of an over the air (OTA) tuner/decoder box that outputs
MPEG2 HDTV data. There are also one or two DirectTV satellite
decoder boxes that output HDTV MPEG2 data. In the above
examples, a
Firewire digital connection (aka IEEE 1394, aka i.Link) is used to
output the MPEG2 HDTV data.
The JVC HM-DH30000 DVHS recorder is an example of a recorder than
records MPEG2 HDTV data from a Firewire
connection. (
http://www.jvc.com/product.jsp?productId=PRD4603000).
Note, this recorder
cannot record analog HDTV 3 cable component
video (the typical output of a cable TV tuner/decoder box)
There are no consumer solutions around for recording HDTV off of analog
component (3 cable) outputs. The component analog output just has
too much bandwidth to easily record onto tape.
There are realtime HDTV quality analog to digital converter (ADC) &
MPEG2 encoder packages, but again, they're way too expensive for
consumers. (If anyone thinks I'm wrong on this, please please correct
me)
[Update: There is now a
Blackmagic
DeckLink HD PCI MPEG2 encoder card that runs on the Apple G5
Macintosh. The cost of the card is about $2k and the cost
of the G5 is roughly $3K. Sep 25, 2003]
The vast majority of cable boxes do not have Firewire/MPEG2 outputs
(eventhough the MPEG2 data is probably used somewhere in the guts of
the cable boxes).
The
www.169time.com
company that one of the other responder posted appears to be taking the
approach where they physically modify the cable box to add an
Firewire/MPEG2 output. However they can't do this for the
Scientific Atlanta models 3100/4200 or Motorola model 5100 cable
boxes (which I have). 169time has an offer to send in your cable
box for evaluation, which sounds sort of flaky to me.
Many HDTV's support a DVI raw data digital video interface. This
solution uses uncompressed HDTV data (not encoded/compressed into the
much lower data rate MPEG2 format). Again, the data rate
for DVI is way too high to easily record onto tape. But
just in case, almost all future DVI interfaces will include HDCP (hi
def content protection) encryption to prevent unauthorized
copying/recording.
Both cable TV and over the air TV transmit MPEG2 data modulated onto a
radio frequency signal, but they use different modulation schemes
(8-VSB for over the air, QAM for cable). This means that
tuners which can handle over the air signals are different from tuners
which can handle cable signals. I'm sure there's some good
technical reason for this, but I don't know what it is.
I don't understand why no one makes a cable TV box with MPEG2/Firewire
outputs. Maybe because the FCC mandated HDTV reception for
over the air broadcasts, but not for cable TV, making HDTV tuner
technology a common off the shelf thing, so 3rd party manufacturers
could easily get their hands on the chips to decode over the air
HDTV. This is just conjecture.
[Comcast uses the Motorola
DCT5100 as it's
HDTV cable TV set top decoder box. The DCT5100
does have
a DVI output, but it's currently disabled by firmware in the box]
IMHO, the entertainment industry blames the falling music revenues on
digital pirating and they're gonna make damn sure the same thing
doesn't happen with movies. HDTV scares the crap out of
them and they're pulling out all stops to make sure there's no consumer
technology able to copy HDTV without heavy
encryption/authorization/content protection technology (except if it's
broadcast over the air with commercials).
See
http://www.timefordvd.com/tutorial/DigitalTVTutorial.shtml
for a background tutorial on the HDTV technology involved.
I bet this was a long response than you were expecting ;)