HDTV and EDTV

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Archived from groups: alt.tv.tech.hdtv (More info?)

"L Alpert" <alpertl@xxcomcast.net> wrote in message
news:NJHAd.281566$V41.265950@attbi_s52...
> Alan Figgatt wrote:
>> L Alpert wrote:
>>> Hasenpfeffer wrote:
>>>
>>>> Here's my understanding of the situation:
>>>>
>>>> 480i with a bandwidth of 6 MHz is SDTV. Also called NTSC here in
>>>> North America.
>>>> 720p and 1080i is HDTV. There may be other formats, like 1080p,
>>>> considered to be HDTV but rarely used.
>>>> 480p is EDTV (since it's neither SDTV nor HDTV, and can have a
>>>> higher bandwidth than SDTV, e.g. downsampled HDTV)
>>>>
>>>> I hope it's enough language to communicate.
>>>
>>>
>>> Actually, from what I understand (and I could be wrong), the 480p is
>>> done internal to the unit, similar to a DVD player, so the bandwidth
>>> would be the same as the input is still 480i (unless, of course,
>>> these units can accept an input of 720p or 180i and downscale it to
>>> 480p). Though I can't see the sense of setting up for HD service to
>>> downscale.....
>>
>> You are thinking about the 480p progressive scan feature for DVDs
>> which can deinterlaced film source material into 720x480p. This
>> feature is also known as 3:2 pull down. This is not the same as 480p
>> widescreen source broadcasts as one of the ATSC standards, which Fox
>> used to do until they switched to 720p this year.
>
> How many stations are going to broadcast the 480p version of DTV, and how
> many cable and satellite carriers will offer this scale of service?
>
>
>>
>> There are 18 different formats accepted for ATSC many of which are
>> not HD. See http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html for
>> the list. Enhanced Definition for OTA broadcasts effectively means
>> the 704x480p 16:9 standard, but with Fox dropping it, I don't know if
>> there are any stations broadcasting at that standard in the US any
>> more. All of the major networks are either 720p60 or 1080i60 now.
>
> Well, I wasn't sure if the EDTV was expecting the source to be 480p or if
> was scaling it similar to PS DVD players.
>
>>
>> For TV sets, ED has come to mean 16:9 480p sets. Fixed pixel ED
>> plasmas have a resolution of 852x480p pixels. At 852 horizontal
>> pixels, these sets do have higher resolution than the 720 or 704
>> pixels of resolution for US encoded DVDs or ED broadcasts. They
>> upscale DVDs horizontally & downscale the 720p or 1080i signals to
>> 480p and still provide a pretty good picture for medium sized 37" or
>> 42" screens at typical 8 or 10 feet viewing distance.
>
> I would still have a problem with going through the trouble of obtaining a
> 720p or 1080i source signal and downscale it.
>

Well, it only costs me an additional $5 a month to "obtain a 720p or 1080i
source signal" and downscale it for my EDTV... which looks great by the way.
Doesn't seem like it's too much trouble. Of course, like you said... you
have a problem with it. Too bad for you.
Sac D

 

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Archived from groups: alt.tv.tech.hdtv (More info?)

Brad Houser wrote:
> "L Alpert" <alpertl@xxcomcast.net> wrote in message
> news😱VBAd.584319$wV.467742@attbi_s54...
>> Hasenpfeffer wrote:
>>> Here's my understanding of the situation:
>>>
>>> 480i with a bandwidth of 6 MHz is SDTV. Also called NTSC here in
>>> North America.
>>> 720p and 1080i is HDTV. There may be other formats, like 1080p,
>>> considered to be HDTV but rarely used.
>>> 480p is EDTV (since it's neither SDTV nor HDTV, and can have a
>>> higher bandwidth than SDTV, e.g. downsampled HDTV)
>>>
>>> I hope it's enough language to communicate.
>>
>> Actually, from what I understand (and I could be wrong), the 480p is
>> done internal to the unit, similar to a DVD player, so the bandwidth
>> would be the same as the input is still 480i (unless, of course,
>> these units can accept an input of 720p or 180i and downscale it to
>> 480p).
>
> Not True. Progressive scan DVD players do create the 480p signal, as
> would HDTV tuners. The bandwidth is therefore double 480i, since 2x
> the number of scan lines are sent each 1/60th of a second. The 480p
> capable TV doesn't receive one field and repeat it, which is what a
> line doubler does.
>
> Brad H

Yes, but the native input signal (in this case, from the actual DVD) is
still 480i. The extra bandwidth or data storage is not needed for the input
signal, only from the output of the player to the viewing device.
If the HD tuner (or in this case the EDTV tuner) is the one that is
generating the progressive scan signal from a standard 480i signal, the
input bandwidth to the tuner still only needs to be enough to support the
480i.

Of course, if it will need to downconvert 720p or 1080i to 480p, then the
input bandwidth of the device (tuner) will need to be higher to support
those signals as well.

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

Sac D wrote:
> "L Alpert" <alpertl@xxcomcast.net> wrote in message
> news:NJHAd.281566$V41.265950@attbi_s52...
>> Alan Figgatt wrote:
>>> L Alpert wrote:
>>>> Hasenpfeffer wrote:
>>>>
>>>>> Here's my understanding of the situation:
>>>>>
>>>>> 480i with a bandwidth of 6 MHz is SDTV. Also called NTSC here in
>>>>> North America.
>>>>> 720p and 1080i is HDTV. There may be other formats, like 1080p,
>>>>> considered to be HDTV but rarely used.
>>>>> 480p is EDTV (since it's neither SDTV nor HDTV, and can have a
>>>>> higher bandwidth than SDTV, e.g. downsampled HDTV)
>>>>>
>>>>> I hope it's enough language to communicate.
>>>>
>>>>
>>>> Actually, from what I understand (and I could be wrong), the 480p
>>>> is done internal to the unit, similar to a DVD player, so the
>>>> bandwidth would be the same as the input is still 480i (unless, of
>>>> course, these units can accept an input of 720p or 180i and
>>>> downscale it to 480p). Though I can't see the sense of setting up
>>>> for HD service to downscale.....
>>>
>>> You are thinking about the 480p progressive scan feature for DVDs
>>> which can deinterlaced film source material into 720x480p. This
>>> feature is also known as 3:2 pull down. This is not the same as 480p
>>> widescreen source broadcasts as one of the ATSC standards, which Fox
>>> used to do until they switched to 720p this year.
>>
>> How many stations are going to broadcast the 480p version of DTV,
>> and how many cable and satellite carriers will offer this scale of
>> service?
>>>
>>> There are 18 different formats accepted for ATSC many of which are
>>> not HD. See http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html for
>>> the list. Enhanced Definition for OTA broadcasts effectively means
>>> the 704x480p 16:9 standard, but with Fox dropping it, I don't know
>>> if there are any stations broadcasting at that standard in the US
>>> any more. All of the major networks are either 720p60 or 1080i60
>>> now.
>>
>> Well, I wasn't sure if the EDTV was expecting the source to be 480p
>> or if was scaling it similar to PS DVD players.
>>
>>>
>>> For TV sets, ED has come to mean 16:9 480p sets. Fixed pixel ED
>>> plasmas have a resolution of 852x480p pixels. At 852 horizontal
>>> pixels, these sets do have higher resolution than the 720 or 704
>>> pixels of resolution for US encoded DVDs or ED broadcasts. They
>>> upscale DVDs horizontally & downscale the 720p or 1080i signals to
>>> 480p and still provide a pretty good picture for medium sized 37" or
>>> 42" screens at typical 8 or 10 feet viewing distance.
>>
>> I would still have a problem with going through the trouble of
>> obtaining a 720p or 1080i source signal and downscale it.
>>
>
> Well, it only costs me an additional $5 a month to "obtain a 720p or
> 1080i source signal" and downscale it for my EDTV... which looks
> great by the way. Doesn't seem like it's too much trouble. Of
> course, like you said... you have a problem with it. Too bad for you.
> Sac D

I would have a problem with it for a 480p output display, but since I have a
1080i IO from both cable and OTA, it is not too bad for me at all.

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

Bandwidth is the product of horizontal resolution x vertical resolution x
refresh rate. 480p has twice the bandwidth as 480i only if hor. res. and
vert. res. stay the same.
DVD only hold a certain amount of picture information. I believe that 480p
is a good format to display all the information. If nothing else, than for
the absence of scan lines on CRT's. My computer creates the signal from the
DVD, but no matter how high I set the resolution, the quality does not
increase. The bandwidth is there, but not "used". Just a larger bucket for
the same amount of water.

"Brad Houser" <bradDOThouser@intel.com> wrote in message
news:cqvimt$oqt$1@news01.intel.com...
>
> "L Alpert" <alpertl@xxcomcast.net> wrote in message
> news😱VBAd.584319$wV.467742@attbi_s54...
>> Hasenpfeffer wrote:
>> > Here's my understanding of the situation:
>> >
>> > 480i with a bandwidth of 6 MHz is SDTV. Also called NTSC here in North
>> > America.
>> > 720p and 1080i is HDTV. There may be other formats, like 1080p,
>> > considered to be HDTV but rarely used.
>> > 480p is EDTV (since it's neither SDTV nor HDTV, and can have a higher
>> > bandwidth than SDTV, e.g. downsampled HDTV)
>> >
>> > I hope it's enough language to communicate.
>>
>> Actually, from what I understand (and I could be wrong), the 480p is done
>> internal to the unit, similar to a DVD player, so the bandwidth would be
> the
>> same as the input is still 480i (unless, of course, these units can
>> accept
>> an input of 720p or 180i and downscale it to 480p).
>
> Not True. Progressive scan DVD players do create the 480p signal, as would
> HDTV tuners. The bandwidth is therefore double 480i, since 2x the number
> of
> scan lines are sent each 1/60th of a second. The 480p capable TV doesn't
> receive one field and repeat it, which is what a line doubler does.
>
> Brad H
>
>

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

Hasenpfeffer wrote:
> Bandwidth is the product of horizontal resolution x vertical
> resolution x refresh rate. 480p has twice the bandwidth as 480i only
> if hor. res. and vert. res. stay the same.
> DVD only hold a certain amount of picture information. I believe that
> 480p is a good format to display all the information. If nothing
> else, than for the absence of scan lines on CRT's. My computer
> creates the signal from the DVD, but no matter how high I set the
> resolution, the quality does not increase. The bandwidth is there,
> but not "used". Just a larger bucket for the same amount of water.

My point is (and maybe I haven't been able to put it into the right words)
that if the input signal to the device is 480i and the progressive scan is
the device output signal, then the bandwidth needed for the input to the
device (be it cable, satellite or OTA) still only needs to enough to support
the 480i.

If the input to the device is 480p, then yes, the bandwidth needed is
doubled.

>
> "Brad Houser" <bradDOThouser@intel.com> wrote in message
> news:cqvimt$oqt$1@news01.intel.com...
>>
>> "L Alpert" <alpertl@xxcomcast.net> wrote in message
>> news😱VBAd.584319$wV.467742@attbi_s54...
>>> Hasenpfeffer wrote:
>>>> Here's my understanding of the situation:
>>>>
>>>> 480i with a bandwidth of 6 MHz is SDTV. Also called NTSC here in
>>>> North America.
>>>> 720p and 1080i is HDTV. There may be other formats, like 1080p,
>>>> considered to be HDTV but rarely used.
>>>> 480p is EDTV (since it's neither SDTV nor HDTV, and can have a
>>>> higher bandwidth than SDTV, e.g. downsampled HDTV)
>>>>
>>>> I hope it's enough language to communicate.
>>>
>>> Actually, from what I understand (and I could be wrong), the 480p
>>> is done internal to the unit, similar to a DVD player, so the
>>> bandwidth would be the same as the input is still 480i (unless, of
>>> course, these units can accept
>>> an input of 720p or 180i and downscale it to 480p).
>>
>> Not True. Progressive scan DVD players do create the 480p signal, as
>> would HDTV tuners. The bandwidth is therefore double 480i, since 2x
>> the number of
>> scan lines are sent each 1/60th of a second. The 480p capable TV
>> doesn't receive one field and repeat it, which is what a line
>> doubler does. Brad H

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

"L Alpert" <alpertl@xxcomcast.net> wrote in message
news:NJHAd.281566$V41.265950@attbi_s52...
>
> Well, I wasn't sure if the EDTV was expecting the source to be 480p or if
> was scaling it similar to PS DVD players.

It can do either. If the source is 480p or 720p DTV, it is already
progressive. If it's a DVD of a movie, it can be effectively treated as
progressive much of the time. If it's 1080i DTV, when downscaling, the
interlace disappears. The biggest problem is 480i TV (NTSC etc.), but that's
always going to be a problem, and at least it usually looks a lot better if
it only has to de-interlace, and not scale as well.

> I would still have a problem with going through the trouble of obtaining a
> 720p or 1080i source signal and downscale it.

I suppose, but it doesn't need to degrade the quality quite as much as it
would seem. For one thing, all TV encodes color at lower resolution than the
grayscale (luma). DVD and DTV both encode it at 1/2 the resolution in each
direction as the luma. (It is much worse for NTSC and worse still for VHS.)
An EDTV set has the opportunity to display the color portion of an HD signal
at its full resolution, or nearly so, meaning only the luma portion really
needs to be scaled down. Another factor is that there isn't as much visual
variation in quality from signal to signal as there would be for an HD set.
HDTV looks good, not as subtly detailed or sharp as on an HD set, but still
very good. DVD also looks very good, as does widescreen 480p DTV. Even
standard TV usually looks pretty good on these sets, as it doesn't need to
be scaled. And the only time interlace comes into play at all is on a 480i
signal, so you nearly always have what looks like a nice stable
progressive-scan image. In addition, for many typical viewing situations
(considering size of set, viewing distance, and visual acuity of the
viewers), the perceived difference between this and a true HD set may be
minimal. So all in all, particularly if it saves a few thousand dollars, for
many people an ED set makes as much sense as an HD set. Besides, the
majority of people buying plasma sets seem more concerned with getting a
flat TV than with getting HDTV.

 

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Archived from groups: alt.tv.tech.hdtv (More info?)

"L Alpert" <alpertl@xxcomcast.net> wrote in message
news:%VCBd.737914$mD.435472@attbi_s02...
> Hasenpfeffer wrote:
>> Bandwidth is the product of horizontal resolution x vertical
>> resolution x refresh rate. 480p has twice the bandwidth as 480i only
>> if hor. res. and vert. res. stay the same.
>> DVD only hold a certain amount of picture information. I believe that
>> 480p is a good format to display all the information. If nothing
>> else, than for the absence of scan lines on CRT's. My computer
>> creates the signal from the DVD, but no matter how high I set the
>> resolution, the quality does not increase. The bandwidth is there,
>> but not "used". Just a larger bucket for the same amount of water.
>
> My point is (and maybe I haven't been able to put it into the right words)
> that if the input signal to the device is 480i and the progressive scan is
> the device output signal, then the bandwidth needed for the input to the
> device (be it cable, satellite or OTA) still only needs to enough to
> support the 480i.
>
> If the input to the device is 480p, then yes, the bandwidth needed is
> doubled.

ED plasma displays are capable of 60 frames per second progressive-scan
display at 480x852 or so resolution. Like many HDTVs, most EDTVs do not have
ATSC/DTV digital tuners built in, containing only an NTSC tuner. However,
that's not how you'd want to watch DVD or digital cable or satellite, let
alone (H)DTV. When it comes to ATSC DTV tuners, they all have to be able to
receive all the formats, including the HD formats, so yes, the input would
be 480p60, 720p60, or whatever, then sent to the EDTV display via component
or DVI. (The signal would generally be downconverted to 480p60 inside the
digital tuner.)

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

Matthew Vaughan wrote:
> "L Alpert" <alpertl@xxcomcast.net> wrote in message
> news:NJHAd.281566$V41.265950@attbi_s52...
>>
>> Well, I wasn't sure if the EDTV was expecting the source to be 480p
>> or if was scaling it similar to PS DVD players.
>
> It can do either. If the source is 480p or 720p DTV, it is already
> progressive. If it's a DVD of a movie, it can be effectively treated
> as progressive much of the time. If it's 1080i DTV, when downscaling,
> the interlace disappears. The biggest problem is 480i TV (NTSC etc.),
> but that's always going to be a problem, and at least it usually
> looks a lot better if it only has to de-interlace, and not scale as
> well.
>> I would still have a problem with going through the trouble of
>> obtaining a 720p or 1080i source signal and downscale it.
>
> I suppose, but it doesn't need to degrade the quality quite as much
> as it would seem. For one thing, all TV encodes color at lower
> resolution than the grayscale (luma). DVD and DTV both encode it at
> 1/2 the resolution in each direction as the luma. (It is much worse
> for NTSC and worse still for VHS.) An EDTV set has the opportunity to
> display the color portion of an HD signal at its full resolution, or
> nearly so, meaning only the luma portion really needs to be scaled
> down. Another factor is that there isn't as much visual variation in
> quality from signal to signal as there would be for an HD set. HDTV
> looks good, not as subtly detailed or sharp as on an HD set, but
> still very good. DVD also looks very good, as does widescreen 480p
> DTV. Even standard TV usually looks pretty good on these sets, as it
> doesn't need to be scaled. And the only time interlace comes into
> play at all is on a 480i signal, so you nearly always have what looks
> like a nice stable progressive-scan image. In addition, for many
> typical viewing situations (considering size of set, viewing
> distance, and visual acuity of the viewers), the perceived difference
> between this and a true HD set may be minimal. So all in all,
> particularly if it saves a few thousand dollars, for many people an
> ED set makes as much sense as an HD set. Besides, the majority of
> people buying plasma sets seem more concerned with getting a flat TV
> than with getting HDTV.

All good points. It seems to have more to do with personal need and/or
finances. As always, caveat emptor. As long as the buyer knows what they
are getting (and hopefully understand).

As for myself, once the flat screen prices drop below my break point (and
I'm not 100% sure what that will be!!!), I will get one capable of 1080i
minimum, maybe 1080p. Until then, I will stick with my RPTV @ 1080i......