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  #1  
Old December 6th 04, 02:21 AM
Larry G
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Default HDTV question

Well for years now, I've been researching HDTV and DTV. Even so much as
writing the FCC back in the mid-90's for info back in the days before I got
my internet connection.

After much reading, I'm fairly knowledgable of the basics in theory, but I
was never actually able to see it as I live far removed from a Circuit City
or a Best Buy until recently when Walmart and Sears began selling the LCD
sets. So, I've got questions.

It's looking like HDTV is getting ready for primetime as the sets are
beginning to dominate Walmart, etc. From what I've seen, the low-end models
are absolutely horrible, like some toy. The picture has these horizontal
lines running through it. Definitely not worth $300 or even $20.

The $1600 models look pretty good. Walmart is showing a widescreen ad of a
triaminic commercial along with an ad for the store. The question is if
anyone has seen this and what resolution it's in. How is Walmart displaying
this - some private satellite connection or videotape? If so, can you now
tape at 720p or 1080i?

My HDTV options are not that great. I'm in rural Riverside County. A large
mountain blocks Palm Springs completely. So most people either have cable or
large overhead antennas to pick up L.A., usually a snowy picture, but those
with large enough antennas can receive a fairly decent picture. Basically
though I'm in a TV blackhole at the mercy of the local cable or satellite
providers. The good news is that with satellite, I don't have to deal with
the Grade-B distant bull that a lot of people have to deal with save CBS
g. The bad news is there's a reason, lol.

The all-or-nothing reception problem with digital causes me concern as most
people around here can only receive L.A. with a snowy picture.

According to AntennaWeb, the only HDTV station I would be able to receive is
KVCR, a public television station out of San Bernardino.

Satellite, large or small, is out of the question as I live in a building
that bans them. So, something like Voom is not an option. Can't have an
overhead antenna either.

Adelphia has recently started offering some L.A. locals of HDTV, but I'm not
sure how many. Question about this: I've heard that cable HDTV is not "true
HDTV", but this was some years ago. Is this still true? How is the quality?

Is buying an HDTV set worth it in this case, with the only option being
AdelphiaHD, or perhaps a signal from KVCR in San Bernardino (which is still
snowy despite being the "local" PBS station)?

What about for DVD viewing and regular old NTSC viewing. Can you buy an LCD
widescreen and receive regular cable over it? Would watching a DVD be like
watching a DVD progressive scan on a computer monitor?

On my monitor, DVDs are superb with the film coming close to watching at a
theater. Videotaped material, however, leaves much to be desired as they are
filmed NTSC, but look like crap on a computer monitor? Does the same thing
happen with videotape-origin on a DVD monitor?

Thanks in advance for answers to my questions,
Larry

  #2  
Old December 6th 04, 02:25 AM
Larry G
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"Larry G" wrote in message ...
Videotaped material, however, leaves much to be desired as they are
filmed NTSC, but look like crap on a computer monitor? Does the same thing
happen with videotape-origin on a DVD monitor?


To clarify, NTSC videotape (like a sitcom or news) looks like crap on my
computer monitor. Does the same thing happen with videotape on an HDTV
monitor?

Larry

  #3  
Old December 6th 04, 02:33 AM
Randy Sweeney
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"Larry G" wrote in message
...
"Larry G" wrote in message ...
Videotaped material, however, leaves much to be desired as they are
filmed NTSC, but look like crap on a computer monitor? Does the same
thing
happen with videotape-origin on a DVD monitor?


To clarify, NTSC videotape (like a sitcom or news) looks like crap on my
computer monitor. Does the same thing happen with videotape on an HDTV
monitor?

Larry


yes... almost painful

the fundamental lack of color resolution in VHS recording seems to be the
underlying cause


  #4  
Old December 6th 04, 07:12 AM
John S. Dyson
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In article ,
"Randy Sweeney" writes:

"Larry G" wrote in message
...
"Larry G" wrote in message ...
Videotaped material, however, leaves much to be desired as they are
filmed NTSC, but look like crap on a computer monitor? Does the same
thing
happen with videotape-origin on a DVD monitor?


To clarify, NTSC videotape (like a sitcom or news) looks like crap on my
computer monitor. Does the same thing happen with videotape on an HDTV
monitor?

Larry


yes... almost painful

the fundamental lack of color resolution in VHS recording seems to be the
underlying cause


(I know that I have diverged a little, but this is meant to be helpful)

Record of NTSC/SDTV (and downconverted HDTV) playing onto HDTV
monitor in SDTV mode:

Device SDTV R/P NTSC R/P

HM30000 DVHS record in VHS Poor Poor
HM30000 DVHS record in SVHS Fair+ Fair- (Laggy) (1)
HM30000 DVHS record in DVHS Near Perfect Fair- (Laggy) (1)

DHR1000 DV25 Near Perfect Near Perfect (2d comb) (2)
DHR1000 DV25 Near Perfect Near Perfect (3d comb) (2)

D9 DV50 Near Perfect+ Near Perfect (2d comb) (3,4)
D9 DV50 Near Perfect+ Near Perfect (3d comb) (3,4)


The best all around record/playback of NTSC type signals, I'd suggest using
the HM30000 and accepting the 3D smear as the cost of removing signal noise
and decoder artifacts. AFAIR, the DVHS record/playback provided a relatively
noise free signal and had a fairly flat multiburst out to at least 4.2MHz.
The chroma bandwidth of the HM30000 seemed to edge out the DHR1000 for reasons
beyond the 4:1:1 and 4:2:0 differences. The difference might have been based
upon the quality of the built-in decoders on the DHR1000 being a little
worse than one might desire. The DHR1000 worked significantly better when
using an external 3D comb, but that complicates set-up for timeshifting.

For record/playback of a fully digital SDTV signal, the DVHS and DV25 are
both nearly perfect. I'd give the DVHS a nod over and above the DV25 because
of the slightly better integrated potential of recording a fully digital
signal (no analog conversion) when using DVHS decks along with firewire
I/O.

SVHS doesnt' have enough color bandwidth to reproduce even the chroma
in NTSC broadcast. Nowdays, SVHS decks seem to do a good job of multiburst
response (beyond what I'd suggest to be a 'good thing' wrt other signal
quality tradeoffs.) IMO, in all but the most non-demanding situations,
SVHS isn't really a good format for when displaying the signal on an HDTV
type monitor. If the only thing that is available is a good SVHS deck,
the so be it, and any image can provide entertainment quality video!!!
(Beyond that, snobbishness isn't really helpful for anyone :-)).

VHS might be going a little too far for displaying a beautiful SDTV signal
on an HDTV quality monitor. Maybe some snobbishness is appropriate here :-).

Notes:
1) The combo of the 3D comb and the MPEG2 encoder on the HM30000 were
borderline severe. The advantage of all of the processing on the HM30000
is that it seems to deal fairly well with imperfect signals.
2) DV25 on the DHR1000 doesn't deal well with lots of excess detail, and so
the comb artifacts (and cross chroma/cross luma) seems to cause the
DHR1000 to perform worse than one might expect on noisy sources. Given
pristine sources, the DHR1000 does a good job (better than SVHS is by
far most cases.)
3) DV50 is able to deal with lots of excess noise and decoder artifacts, while
doing an incredibly good job in record/playback of composite video with
very few encode/decode artifacts. The resulting behavior of using DV50
on a composite signal is to ALMOST provide full composite recording quality
without looking much like the signal has been encoded/decoded. If one
is recording a composite signal, the it is probably best to avoid 3D
encoding/decoding, and use the built-in (probably orthogonal) 2d encoders
in the decks. If the result is to provide a component signal (e.g. DVD
recording), then it is best to use a damned good 3D decoder before the
D9 decks (e.g. use the HM30000 built-in 3D decoders.)
4) D9 (DV50) can provide the same quality (or better) as DV25 after
the 5th full encode/decode generation. D9 encode/decode truly does
look nearly perfect (a signal generator output, even full field, and
full high resolution test patterns look just like the pattern generator
output, even with analog encode/decode.) D9 was used as a basis of
comparison, and it isn't really a viable timeshifting format. I have
used it for timeshifting, but the difference on SDTV record/playback on
DV50 vs. DVHS (full quality) vs. DV25 is unimportant.

Horizontal resolution (the -3dB/-6dB number aren't really a figure
of merit, but mostly result of numerous design/quality tradeoffs):

Format Luma Chroma
DVHS 6.75MHz limiting (540TVL) 3.4MHz limiting (270TVL)
5.5MHz -3dB (440TVL) 3MHz -6dB (240TVL)
DV25 6.75MHz limiting (540TVL) 1.7MHz limiting (135TVL)
5.5MHz -3dB (440TVL) 1.5MHz -6dB (120TVL)
DV50 6.75MHz limiting (540TVL) 3.4Hhz limiting (270TVL)
5.5Mhz -3dB (440TVL) 3MHz -6dB (240TVL)

VHS approx 3.2MHz ABSlimit (260TVL) approx 0.6MHz limit (48TVL)
approx 2.2MHz -3dB? (176TVL) approx 0.4MHz -6dB? (32TVL)

SVHS approx 5.8MHz ABSlimit (464TVL) approx 0.6MHz limit (48TVL)
approx 5.0MHz limit (400TVL)
approx 4.2MHz -3dB? (336TVL) approx 0.4MHz -6dB (32TVL)

SuperBeta approx 3.8MHz ABSlimit (300TVL) approx 0.7MHz limit (56TVL)
approx 3.4MHz limit (270TVL)
approx 2.6MHz -3dB? (200TVL) approx 0.6MHz -6dB? (48TVL)

EDBeta approx 7.3Mhz ABSlimit (580TVL) approx 0.7MHz limit (56TVL)
approx 6.7MHz limit (520TVL)
approx 6MHz -3dB (400TVL) approx 0.6MHz -6dB? (48TVL)

For the DIGITAL formats, the difference in quality isn't well specified
by the frequency response. Digital decks remove detail in the DCT domain
and not primarily in the fourier domain, so the loss of detail isn't very
easy to see in the fourier (frequency response) domain. It is very clear
that DV25 will lose detail in certain cases where DV50 (or sometimes
even MPEG2, on non changing images) might retain detail. Likewise, MPEG2
can lose detail on quick changing frames, while DV25 could maintain the
detail, if the frame doesn't have too much spatial detail. In both
cases, DV50 can usually maintain detail that is lost because of movement
or because of too many fine aspects to a given frame. DV50 can maintain
most fine detail, even if it is quickly changing, thereby blowing away
the quality of SDTV level MPEG2 and/or DV25. My DV50 decks ALMOST maintain
enough luma detail so that a composite video signal could be reproduced
when using the Y signal only (there is color, but highly distorted.) Obviously,
the DV50 compression is too severe and probably even inappapropriate to
maintain the necessary structure of a composite signal!!! Of course, one
would normally use all three of the component inputs.

Again, the -3, -6dB numbers for DIGITAL decks aren't really an indication
of quality, but more result from tradeoffs (e.g. aliasing.) The numbers
are useful to get an idea of the signal loss when comparing with analog
video recording!!! For analog VHS/SVHS/etc, the limit bandwidths are based
upon the recording format frequencies, and the rolloffs are based upon
plausible design and are very approx. The ABSlimit value is the amount
of response that is possible under the best ideal conditions. The SVHS
limit value is the limit that has a plausible chance of providing
reasonable SNR and lack of aliasing (moire)... When pushing the video
luma response beyond the average of sync tip and peak white frequency
(which is the average video frequency) and subtracting the highest
chroma frequency (about 1.2MHz), then the video quality will suffer
substantially -- and if the baseband goes higher than the sync tip frequency
alone, then there will definitely be aliasing (or serious problems.)

For Beta, note that more has to be subtracted from the luma response
because of the BetaHiFi subcarriers. There is some cancelling, but
not enough to ignore the effect of the BetaHiFi subcarriers. I haven't
provided all of the basis of the frequency response numbers, but they
are definitely appropriately sourced.

For EDBeta, notice that IF there was adequate SNR and provided enough
chroma frequency response (which it doesn't), it would make a reasonable
broadcast format. Since it could theoretically provide almost flat
response out to 400TVL for luma, and could be almost flat out to 5MHz,
with enough SNR, it MIGHT actually be theoretically possible to be a full
composite recording format. The biggest problem with EDBeta is the horrible
(relative to everything else about EDBeta) chroma frequency response.

Bottom line, my frequency response numbers for the (s)VHS/Beta are abs
max. It is likely that there'll be more intermod/aliasing/beat products
above those frequencies.

John
  #5  
Old December 8th 04, 12:08 AM
Bill Sharpe
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Adelphia in Santa Monica includes CBS, NBC, ABC, Fox, PBS, ESPN, HBO,
and Showtime HD channels for $10 per month extra. ESPN requires an
additional $1.50 per month. HBO and Showtime require the respective
premium charges. HD pictures are excellent on my Samsung CRT
rear-projection set when programs are broadcast in HD. Digital channels
(above 100) are good, Analog channels (2 - 98) are fair. Videotape of
non-HD channels is not very good. The HD channels come into my VCR as
480p and are not too bad when taped, although a far cry from the
original HD broadcasts. I switched from antenna connections between the
VCR and HD set to audio-video cables and the taped picture improved. By
all means, though, tape in 2-hour mode, not 6-hour! Typically the only
program I tape on a regular basis is CBS Sunday Morning, which airs at
an ungodly 6 am during the pro football season. Although Sunday Morning
isn't broadcast in HD format, taping from channel 902(channel 2's HD
outlet) gives better results than taping from channel 2(analog).

The PBS HD feed contains many reruns and is mostly different than KCET's
regular schedule.

One of these days I'll get a DVR...

Bill

"Larry G" wrote in message
...
Adelphia has recently started offering some L.A. locals of HDTV, but I'm
not
sure how many. Question about this: I've heard that cable HDTV is not
"true
HDTV", but this was some years ago. Is this still true? How is the
quality?

Is buying an HDTV set worth it in this case, with the only option being
AdelphiaHD, or perhaps a signal from KVCR in San Bernardino (which is
still
snowy despite being the "local" PBS station)?



  #6  
Old December 8th 04, 12:56 AM
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Regarding Walmart.... A lot of what they sell is low-end garbage. I
would not buy a RP by RCA, Magnavox or .

Mixed in with the bad, they do have a few very good deals. The best is
probably the 30" Sanyo HT30744 (CRT/DirectView) HDTV with integrated
tuner. For $650, this is a steal. It's widescreen, it's not too bulky,
the 8VSB DTV tuner that's built in is worth about $200 if you were to
buy it external. It's not a bad way to move up to HDTV without making
lifestyle changes and it's not too big to put in the master bedroom, so
at some point it could become a very nice second TV. The Tatung
50"P50BSAT Plasma display is over priced, but some of their stores are
carrying a 50" 480p (EDTV) version of this for about $2400 which is a
fanastic deal. Lastly, the 53" Pioneer SD-533HD5, for $1,586.00 this is
a good deal (not outstanding), this is probably the only CRT
Rear-projection model I would recommend buying (if Walmart is your only
choice).

Regarding your situation. My question is: do you watch a lot of movies
on DVD? If you answer yes, then you'll going to enjoy an HD set even
without HD signal.

  #7  
Old December 8th 04, 12:57 AM
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Regarding Walmart.... A lot of what they sell is low-end garbage. I
would not buy a RP by RCA, Magnavox or .

Mixed in with the bad, they do have a few very good deals. The best is
probably the 30" Sanyo HT30744 (CRT/DirectView) HDTV with integrated
tuner. For $650, this is a steal. It's widescreen, it's not too bulky,
the 8VSB DTV tuner that's built in is worth about $200 if you were to
buy it external. It's not a bad way to move up to HDTV without making
lifestyle changes and it's not too big to put in the master bedroom, so
at some point it could become a very nice second TV. The Tatung
50"P50BSAT Plasma display is over priced, but some of their stores are
carrying a 50" 480p (EDTV) version of this for about $2400 which is a
fanastic deal. Lastly, the 53" Pioneer SD-533HD5, for $1,586.00 this is
a good deal (not outstanding), this is probably the only CRT
Rear-projection model I would recommend buying (if Walmart is your only
choice).

Regarding your situation. My question is: do you watch a lot of movies
on DVD? If you answer yes, then you'll going to enjoy an HD set even
without HD signal.

  #8  
Old December 8th 04, 01:01 AM
Eric
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The $1600 models look pretty good. Walmart is showing a widescreen ad of a
triaminic commercial along with an ad for the store. The question is if
anyone has seen this and what resolution it's in. How is Walmart

displaying
this - some private satellite connection or videotape? If so, can you now
tape at 720p or 1080i?


The brick and mortar retail stores around here are simply just using local
digital HD cable service to demonstrate HD. They tend, however, to have
sets that they want to push on a HD channel while other sets are on a SD
channel.

The only semi-practical HD media currently available is D-VHS (Digital VHS).
D-VHS sets are relatively expensive and there isn't much D-VHS support from
Hollywood. D-VHS uses tapes that are the same physical size of VHS tapes.
Many look at D-VHS as one step forward and two steps back since tape doesn't
allow random access and is considered cumbersome after using DVD discs for
years. HD-DVD (High Definition-DVD, same physical dimension as standard DVD
discs) and it's competitor Blu-Ray (also High Definition discs, but
different physical dimension than standard DVD discs) are what everyone is
waiting for. They are probably 1.5 to 2 years out on the horizon..

I think there might be some "Tivo-type" boxes that allow recording of HD
(?). I know some folks are using computers in various ways to store and
playback HD. HD files are humongous though!


  #9  
Old December 8th 04, 01:13 AM
Eric
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Oh, as for VHS on a HDTV -- I haven't even tried that yet. I have my VHS
player hooked up to a standard TV in the basement. Didn't bother even
trying it out on the HDTV upstairs as I automatically assumed it probably
would be quite ugly on a HDTV. On a HDTV, you can easily make out the
'artifacts' and 'imperfections' of DVD, even in progressive playback.


  #10  
Old December 8th 04, 06:13 AM
Dargo
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On Sun, 5 Dec 2004 17:25:25 -0800, "Larry G"
wrote:

"Larry G" wrote in message ...
Videotaped material, however, leaves much to be desired as they are
filmed NTSC, but look like crap on a computer monitor? Does the same thing
happen with videotape-origin on a DVD monitor?


To clarify, NTSC videotape (like a sitcom or news) looks like crap on my
computer monitor. Does the same thing happen with videotape on an HDTV
monitor?

Larry



I use my JVC HD recorder connected to my Samsung OTA box via fire
wire and record wonderful hd stuff all day long in detroit plus have
bought a few movies in HD and blown my friends minds when they
see it.

Dargo.
 




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