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Digital TV looks like CGA graphics !

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Anonymous
July 10, 2004 3:22:34 AM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

Yes, 4 colors at 320*200 pixels.

I cannot recommend it.

More about : digital cga graphics

Anonymous
July 10, 2004 4:12:52 PM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"Harlan Osier" <maya_egg@hotmail.com> wrote in message
news:89ec59b9.0407092222.34e3fa@posting.google.com...
> Yes, 4 colors at 320*200 pixels.
>
> I cannot recommend it.

Er should be 768x576, and probably 16bit colour, are you perhaps using an
old PC as a display?
Anonymous
July 10, 2004 8:43:46 PM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"R. Mark Clayton" <nospamclayton@btinternet.com> wrote in message
news:ccomg4$2mb$1@hercules.btinternet.com...
>
> "Harlan Osier" <maya_egg@hotmail.com> wrote in message
> news:89ec59b9.0407092222.34e3fa@posting.google.com...
> > Yes, 4 colors at 320*200 pixels.
> >
> > I cannot recommend it.
>
> Er should be 768x576, and probably 16bit colour, are you perhaps using an
> old PC as a display?

In PAL-land DTV is nearer 720x576/704x576 non-square pixels (though some are
540x576 to save bandwith) and the colour bit depth is effectively 24 bit -
with 8 bit sampling of both luma and chroma difference signals (albeit with
slightly less bit depth than 8 bits to allow for overshoot and undershoot -
black is 16 not 0 and white is 235 not 255 - or is it 240 I can never
remember (I think 16-140 is the Colour difference range?) ).

Additionally because the luma resolution is twice that of the chroma both
vertically and horizontally - as 4:2:0 sampling is used for OTA DTV - only
12 bits per luma sample are used to carry picture information i.e.. 4x8 bit
luma "pixels" are accompanied by 1x8 bit Cr and 1x8bit Cb chroma sample
each - so 4x8 + 2x8 = 48 bits per 4 pixels = 12 bits per pixel?

However the OPs observation is probably based on heavily compressed low data
rate feeds that can and do look like they are made up of lego bricks rather
than pixels. On the other hand some DTV can look cracking - though PCs are
usually less than ideal viewing sources as they seldom cope with interlaced
source material that well.

Steve
Related resources
July 10, 2004 10:55:49 PM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"Stephen Neal" <stephen.neal@nospam.as-directed.com> wrote in message
news:ccp2rl$1i3$1$830fa795@news.demon.co.uk...
>
> "R. Mark Clayton" <nospamclayton@btinternet.com> wrote in message
> news:ccomg4$2mb$1@hercules.btinternet.com...
> >
> > "Harlan Osier" <maya_egg@hotmail.com> wrote in message
> > news:89ec59b9.0407092222.34e3fa@posting.google.com...
> > > Yes, 4 colors at 320*200 pixels.
> > >
> > > I cannot recommend it.
> >
> > Er should be 768x576, and probably 16bit colour, are you perhaps using
an
> > old PC as a display?
>
> In PAL-land DTV is nearer 720x576/704x576 non-square pixels (though some
are
> 540x576 to save bandwith) and the colour bit depth is effectively 24 bit -
> with 8 bit sampling of both luma and chroma difference signals (albeit
with
> slightly less bit depth than 8 bits to allow for overshoot and
undershoot -
> black is 16 not 0 and white is 235 not 255 - or is it 240 I can never
> remember (I think 16-140 is the Colour difference range?) ).
>
> Additionally because the luma resolution is twice that of the chroma both
> vertically and horizontally - as 4:2:0 sampling is used for OTA DTV - only
> 12 bits per luma sample are used to carry picture information i.e.. 4x8
bit
> luma "pixels" are accompanied by 1x8 bit Cr and 1x8bit Cb chroma sample
> each - so 4x8 + 2x8 = 48 bits per 4 pixels = 12 bits per pixel?
>
> However the OPs observation is probably based on heavily compressed low
data
> rate feeds that can and do look like they are made up of lego bricks
rather
> than pixels. On the other hand some DTV can look cracking - though PCs
are
> usually less than ideal viewing sources as they seldom cope with
interlaced
> source material that well.
>
> Steve
>
Yup, the SD digital channels can look very bad on an HD set and the color
also needs some gamma correction. Many HD enthusiasts are screaming at the
cable companies for requiring us to subscribe to channels we can't stand to
watch just to get HD. The compression artifacts are almost unnoticeable on
an analog set.

- Barry
Anonymous
July 10, 2004 10:55:52 PM

Archived from groups: alt.video.digital-tv (More info?)

Harlan Osier wrote:

> Yes, 4 colors at 320*200 pixels.
>
> I cannot recommend it.

You must have Insight Digital Cable ..... my off the air
digital TV looks great.

Doug
Anonymous
July 11, 2004 1:41:41 AM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"Barry" <noozguru@earthlink.net> wrote in message
news:VYWHc.11135$R36.6213@newsread2.news.pas.earthlink.net...
>
> "Stephen Neal" <stephen.neal@nospam.as-directed.com> wrote in message
> news:ccp2rl$1i3$1$830fa795@news.demon.co.uk...
> >
> > "R. Mark Clayton" <nospamclayton@btinternet.com> wrote in message
> > news:ccomg4$2mb$1@hercules.btinternet.com...
> > >
> > > "Harlan Osier" <maya_egg@hotmail.com> wrote in message
> > > news:89ec59b9.0407092222.34e3fa@posting.google.com...
> > > > Yes, 4 colors at 320*200 pixels.
> > > >
> > > > I cannot recommend it.
> > >
> > > Er should be 768x576, and probably 16bit colour, are you perhaps using
> an
> > > old PC as a display?
> >
> > In PAL-land DTV is nearer 720x576/704x576 non-square pixels (though some
> are
> > 540x576 to save bandwith) and the colour bit depth is effectively 24
bit -
> > with 8 bit sampling of both luma and chroma difference signals (albeit
> with
> > slightly less bit depth than 8 bits to allow for overshoot and
> undershoot -
> > black is 16 not 0 and white is 235 not 255 - or is it 240 I can never
> > remember (I think 16-140 is the Colour difference range?) ).
> >
> > Additionally because the luma resolution is twice that of the chroma
both
> > vertically and horizontally - as 4:2:0 sampling is used for OTA DTV -
only
> > 12 bits per luma sample are used to carry picture information i.e.. 4x8
> bit
> > luma "pixels" are accompanied by 1x8 bit Cr and 1x8bit Cb chroma sample
> > each - so 4x8 + 2x8 = 48 bits per 4 pixels = 12 bits per pixel?
> >
> > However the OPs observation is probably based on heavily compressed low
> data
> > rate feeds that can and do look like they are made up of lego bricks
> rather
> > than pixels. On the other hand some DTV can look cracking - though PCs
> are
> > usually less than ideal viewing sources as they seldom cope with
> interlaced
> > source material that well.
> >
> > Steve
> >
> Yup, the SD digital channels can look very bad on an HD set and the color
> also needs some gamma correction. Many HD enthusiasts are screaming at
the
> cable companies for requiring us to subscribe to channels we can't stand
to
> watch just to get HD. The compression artifacts are almost unnoticeable
on
> an analog set.

Interesting - the same complaint is levelled at some DTV transmissions in
the UK viewed on 100Hz sets. (In Europe we don't have many progressive, and
almost no HDTV, sets, but we do have 100Hz sets which upconvert 50Hz
interlaced to 100Hz interlaced to reduce large area flicker)

The digital processing used to convert a 50Hz interlaced picture to 100Hz
also emphasises (and in some cases adds to) existing compression artefacts
introduced by MPEG2 coding at low-to-medium data rates.

I wonder if US HDTVs are using similar digital processing when displaying
480i material at 1080i or 720p? (I'm assuming US HDTV sets don't display
480/60i SDTV in native mode and instead upconvert - I would be surprised if
the TVs ran at both SDTV and HDTV scanning rates?)

Steve

>
> - Barry
>
>
>
Anonymous
July 11, 2004 1:41:42 AM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

Stephen Neal wrote:

>
> I wonder if US HDTVs are using similar digital processing when displaying
> 480i material at 1080i or 720p?

Some sets do marvelous upconversions. Mine does, realistically
speaking it is excellent. Currently Fox is
doing a 480i -> 720p at the station and it is very very
marvelous ... far better than DVD. In the fall they are going
to go to real 720p.

Doug McDonald
Anonymous
July 11, 2004 3:44:25 PM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"Doug McDonald" <mcdonald@scs.uiuc.edu> wrote in message
news:ccq0fp$h5l$1@news.ks.uiuc.edu...
> Stephen Neal wrote:
>
> >
> > I wonder if US HDTVs are using similar digital processing when
displaying
> > 480i material at 1080i or 720p?
>
> Some sets do marvelous upconversions. Mine does, realistically
> speaking it is excellent.

Glad to hear it. Intellectually it struck me as easier to do a 480/50i to
1080/50i scale without mangling the picture - whereas 576/50i to 576/100i
involves interpolation of intermediate fields and lots of guestimating in
the temporal domain (which can go quite badly wrong)

I guess what your set is doing is similar to the DRC50/1250 settings on
high-end DRC sets sold by Sony in the UK - which must be close to a 576/50i
to 1152/50i scale - and this has always (to my eyes) looked better than the
same set in DRC100 mode (which is 576/50i to 576/100i) with far fewer
processing artefacts.

> Currently Fox is
> doing a 480i -> 720p at the station and it is very very
> marvelous ...

Yep - if you have the bandwith much better to let the broadcaster do the
upconversion :

1. They have an uncompressed (or lightly compressed) 480/60i source feed so
will only be scaling/frame rate converting the video and not the artefacts
introduced with broadcast compression (as would be the case if you
upconverted an off-air signal)
2. They will be using a broadcast quality upconverter rather than a couple
of dollars worth of in-TV DSP. Should be better quality.

> far better than DVD.

Yep - if it is sourced from a broadcast quality 480i feed, and the 720p
signal is broadcast at a decent data rate, then it should outperform DVD,
but is probably using 1.5-4 times the data rate of an average DVD master?

> In the fall they are going
> to go to real 720p.

Good news.

Looks like we'll be waiting another year or two for HD services for the UK -
though this may mean we get an MPEG4 or similar based system instead of
MPEG2 - though AIUI no decision has yet been made. (Sky have announced their
move to HD - I suspect for movies and their main entertainment channel which
is mainly US imports, many of which are produced in HD? The BBC have
suggested they are considering it, and have announced a wish for all
non-soap drama to be produced in HD by 2006, and I guess most flagship
productions will be HD, though the Beeb current policy is that extra costs
for HD production should be met by coproduction not the UK viewer/licence
fee payer who can't watch in HD yet)

Steve
Anonymous
July 11, 2004 3:44:26 PM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

Stephen Neal wrote:

>
>
> Glad to hear it. Intellectually it struck me as easier to do a 480/50i to
> 1080/50i scale without mangling the picture

Mine does NOT do 480i -> 1080i, it does 480@60i -> 720@60p


>
> I guess what your set is doing is similar to the DRC50/1250 settings on
> high-end DRC sets sold by Sony in the UK
>

No, since my set is "progressive".

>
>>Currently Fox is
>>doing a 480i -> 720p at the station and it is very very
>>marvelous ...
>
>
> Yep - if you have the bandwith much better to let the broadcaster do the
> upconversion :
>
> 1. They have an uncompressed (or lightly compressed) 480/60i source feed so
> will only be scaling/frame rate converting the video and not the artefacts
> introduced with broadcast compression


> 2. They will be using a broadcast quality upconverter rather than a couple
> of dollars worth of in-TV DSP. Should be better quality.

I don't think this makes a difference ... the commercial ubiquitous
Faroujda chips are excellent. The difference is in the uncompressed
video coming in, with full resolution in all colors.


Doug McDonald
July 11, 2004 11:27:16 PM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"Stephen Neal" <stephen.neal@nospam.as-directed.com> wrote in message
news:ccr5md$dsq$1$830fa17d@news.demon.co.uk...
>
> "Doug McDonald" <mcdonald@scs.uiuc.edu> wrote in message
> news:ccq0fp$h5l$1@news.ks.uiuc.edu...
> > Stephen Neal wrote:
> >
> > >
> > > I wonder if US HDTVs are using similar digital processing when
> displaying
> > > 480i material at 1080i or 720p?
> >
> > Some sets do marvelous upconversions. Mine does, realistically
> > speaking it is excellent.
>
> Glad to hear it. Intellectually it struck me as easier to do a 480/50i to
> 1080/50i scale without mangling the picture - whereas 576/50i to 576/100i
> involves interpolation of intermediate fields and lots of guestimating in
> the temporal domain (which can go quite badly wrong)
>
> I guess what your set is doing is similar to the DRC50/1250 settings on
> high-end DRC sets sold by Sony in the UK - which must be close to a
576/50i
> to 1152/50i scale - and this has always (to my eyes) looked better than
the
> same set in DRC100 mode (which is 576/50i to 576/100i) with far fewer
> processing artefacts.
>
> > Currently Fox is
> > doing a 480i -> 720p at the station and it is very very
> > marvelous ...
>
> Yep - if you have the bandwith much better to let the broadcaster do the
> upconversion :
>
> 1. They have an uncompressed (or lightly compressed) 480/60i source feed
so
> will only be scaling/frame rate converting the video and not the artefacts
> introduced with broadcast compression (as would be the case if you
> upconverted an off-air signal)
> 2. They will be using a broadcast quality upconverter rather than a couple
> of dollars worth of in-TV DSP. Should be better quality.
>
> > far better than DVD.
>
> Yep - if it is sourced from a broadcast quality 480i feed, and the 720p
> signal is broadcast at a decent data rate, then it should outperform DVD,
> but is probably using 1.5-4 times the data rate of an average DVD master?
>
> > In the fall they are going
> > to go to real 720p.
>
> Good news.
>
> Looks like we'll be waiting another year or two for HD services for the
UK -
> though this may mean we get an MPEG4 or similar based system instead of
> MPEG2 - though AIUI no decision has yet been made. (Sky have announced
their
> move to HD - I suspect for movies and their main entertainment channel
which
> is mainly US imports, many of which are produced in HD? The BBC have
> suggested they are considering it, and have announced a wish for all
> non-soap drama to be produced in HD by 2006, and I guess most flagship
> productions will be HD, though the Beeb current policy is that extra costs
> for HD production should be met by coproduction not the UK viewer/licence
> fee payer who can't watch in HD yet)
>
> Steve
>
In hindsight they should have made one standard for all the world not based
on AC line frequency since that isn't needed anymore. Your computer doesn't
need it so why should your TV?

Some of the new cable boxes are going to use MPEG-4 instead of MPEG-2 for
HD.

- Barry
Anonymous
July 12, 2004 2:50:53 AM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

"Harlan Osier" <maya_egg@hotmail.com> a écrit dans le message de news:
89ec59b9.0407092222.34e3fa@posting.google.com...

FYI, all : This guys starts stupid threads on all newsgroups
(alt.satellite.tv.europe, alt.technology.smartcards,
alt.video.satellite.MPEG-DVB ...), and it's really surprising how people
take him seriously !
Anonymous
July 12, 2004 3:20:46 AM

Archived from groups: alt.video.digital-tv,can.ai (More info?)

Doug McDonald wrote:
> Stephen Neal wrote:
>
>>
>>
>> Glad to hear it. Intellectually it struck me as easier to do a
>> 480/50i to 1080/50i scale without mangling the picture
>
> Mine does NOT do 480i -> 1080i, it does 480@60i -> 720@60p

Aha - sorry - mis-applied assumption.

>
>
>>
>> I guess what your set is doing is similar to the DRC50/1250 settings
>> on high-end DRC sets sold by Sony in the UK
>>
>
> No, since my set is "progressive".

Yep - as mentioned above.

>
>>
>>> Currently Fox is
>>> doing a 480i -> 720p at the station and it is very very
>>> marvelous ...
>>
>>
>> Yep - if you have the bandwith much better to let the broadcaster do
>> the upconversion :
>>
>> 1. They have an uncompressed (or lightly compressed) 480/60i source
>> feed so will only be scaling/frame rate converting the video and not
>> the artefacts introduced with broadcast compression
>
>
>> 2. They will be using a broadcast quality upconverter rather than a
>> couple of dollars worth of in-TV DSP. Should be better quality.
>
> I don't think this makes a difference ... the commercial ubiquitous
> Faroujda chips are excellent. The difference is in the uncompressed
> video coming in, with full resolution in all colors.


Err - but there is little difference between SDTV and HDTV in that respect.
Either you get a component digital 480i SDTV signal or a component digital
720p/1080i HDTV signal over a DTV channel surely - no NTSC or PAL composite
artefacts via either delivery method - no-one actually runs stations
analogue these days do they ?

Certainly all UK digital TV platforms are digital component (and almost all
TV production these days is digital component - barring some local stuff)
and most set top boxes will output RGB analogue via their SCART connectors -
offering a major quality improvement over analogue PAL reception (assuming
decent DTV data rates are used - which isn't always the case)

My observations are that the conversion from 576/50i RGB to 576/100i RGB
(though whether this is via 576/50i and/or 100i YCrCb I'm not sure) there
are still observable artefacts introduced in every UK 100Hz set I have seen.
I have also seen Faroudja scaling - thoug they aren't ubiquitous in
direct-view CRT sold in Europe (I don't think Sony, Philips, Panasonic or
JVC mention them in their UK bumph - though I may be wrong.) They are more
likely to be seen in the non-direct view arena (front/rear projection etc.)
Do Faroudja do interlace->interlace conversion (i.e. 50->100 or 60->120?)

Steve
Anonymous
July 12, 2004 3:20:47 AM

Archived from groups: alt.video.digital-tv (More info?)

Stephen Neal wrote:

>>
>>I don't think this makes a difference ... the commercial ubiquitous
>>Faroujda chips are excellent. The difference is in the uncompressed
>>video coming in, with full resolution in all colors.
>
>
>
> Err - but there is little difference between SDTV and HDTV in that respect.
> Either you get a component digital 480i SDTV signal or a component digital
> 720p/1080i HDTV signal over a DTV channel surely

I have no idea what those words mean. What do you mean by "you"? ...
the ultimate home viewer of the station? The home viewer
gets MPEG2 digital, which has half the luma resolution both
vertical and horizontal, unless it is 480i, when the vertical
color resolution is a quarter the possible (100% Kell factor)
luma resolution.


- no NTSC or PAL composite
> artefacts via either delivery method - no-one actually runs stations
> analogue these days do they ?
>
Of course many stations are run analog these days. Most NTSCs are.
Nobody in their right mind would convert a station to all-digital
unless it were HDTV capable these days, at least network pass-thru
HD. Yes, in the past some did. Many stations are converting
just enough to digital to do network HD passthrough.



> Certainly all UK digital TV platforms are digital component (and almost all
> TV production these days is digital component - barring some local stuff)
> and most set top boxes will output RGB analogue via their SCART connectors -
> offering a major quality improvement over analogue PAL reception (assuming
> decent DTV data rates are used - which isn't always the case)
>

Europe is not the US ... we have well over a thousand TV stations,
of which probably a half are full-production capable,
as opposed to you people who are almost all repeaters ...
how many full TV stations with their own local production
facilities are there in the UK?

> Do Faroudja do interlace->interlace conversion (i.e. 50->100 or 60->120?)


I have no idea. It certainly is not what they are usually used
for, which is 480@60i -> 480@60p conversion with 2:3 pulldown
detection and fixup and full NTSC decoding (i.e. using
both alternate lines and alternate frames, so-called "3D" ...
which is not possible with PAL.)

Doug McDonald
Anonymous
July 12, 2004 5:07:11 PM

Archived from groups: alt.video.digital-tv (More info?)

Doug McDonald wrote:
> Stephen Neal wrote:
>
>>>
>>> I don't think this makes a difference ... the commercial ubiquitous
>>> Faroujda chips are excellent. The difference is in the uncompressed
>>> video coming in, with full resolution in all colors.
>>
>>
>>
>> Err - but there is little difference between SDTV and HDTV in that
>> respect. Either you get a component digital 480i SDTV signal or a
>> component digital 720p/1080i HDTV signal over a DTV channel surely
>
> I have no idea what those words mean. What do you mean by "you"? ...

Sorry - posting in the evening when tired and being a bit ambiguous.

What I was trying to convey was that surely the difference in received HDTV
(1080/60i, 720/60p) and SDTV (480/60i, 576/50i) resolution and colour space
was only the spatial scaling - with 4:2:0 MPEG2 being used for both - and
thus both having full-gamut component digital outputs at the domestic
receiver. This only being the case if the SDTV feed were derived from a
digital feed that hasn't been through an NTSC or PAL analogue path.

I accept what I think is your argument - that 4:2:2 480i scaled/upconverted
to 4:2:2 equivalent 720p then coded to 4:2:0 equivalent 720p for TX will
look better than 4:2:0 received MPEG2 480i scaled and upconverted to 720p
4:2:2 equivalent at home.

> the ultimate home viewer of the station? The home viewer
> gets MPEG2 digital, which has half the luma resolution both
> vertical and horizontal, unless it is 480i, when the vertical
> color resolution is a quarter the possible (100% Kell factor)
> luma resolution.

Yep - though 4:2:2 MPEG2 is commonly deployed within the broadcast chains -
either for contribution / distribution links - though 4:2:0 is often
deployed as well for distribution - and also for server cacheing prior to
TX. (Though the data rates are much higher than typical DVB / ATSC SD or HD
transmission rates - and short length GOPs are used, or I-frame only)...

Not sure what your luma resolution refers to - surely 4:2:2 SDTV broadcast
as 4:2:0 SDTV via MPEG2 has the same resolution at the receiver as the
broadcast centre - there is no loss in horizontal luminance resolution
assuming 720x576 transmission is used (some broadcasters in the UK are using
540x576 to save bandwith...)

>
>
> - no NTSC or PAL composite
>> artefacts via either delivery method - no-one actually runs stations
>> analogue these days do they ?
>>
> Of course many stations are run analog these days.

Ah - a major UK/US difference.

Most UK broadcasters are SDTV throughout - a process started in the
early-mid 90s as studios were upgraded. At that point a decision was taken
by most broadcasters to move to digital production (and most studios began
being equipped with 4:3/16:9 switchable cameras). In the UK the only 4:3
analogue production left in the mainstream broadcast arena are really the
BBC local TV News outfits, though some of these are now 16:9 digital. The
local TV switching is engineered such that the DTV signal passes through
untouched by PAL analogue footprints until the actual junction to local
programming, on analogue the path is a little different - but the SDTV and
analogue versions of the BBC networks are distributed independently. (BBC
analogue is mainly sent to local broadcast centres as 140Mbs
lightly-compressed PAL digital - with occasionally 34Mbs used - whereas the
SDTV signal is distributed at about 9Mbs MPEG2, and permanently decoded to
SDI before recoding to 4.8Mbs CBR at each centre.)

> Most NTSCs are.

Ah - most PALs aren't... Certainly in the UK.

> Nobody in their right mind would convert a station to all-digital
> unless it were HDTV capable these days, at least network pass-thru
> HD. Yes, in the past some did. Many stations are converting
> just enough to digital to do network HD passthrough.

Surely you can't get new analogue kit these days at a decent level though -
so if you have to replace a local news gallery, or a small local production
studio, you'd go SDTV rather than HD wouldn't you?

>
>
>
>> Certainly all UK digital TV platforms are digital component (and
>> almost all TV production these days is digital component - barring
>> some local stuff) and most set top boxes will output RGB analogue
>> via their SCART connectors - offering a major quality improvement
>> over analogue PAL reception (assuming decent DTV data rates are used
>> - which isn't always the case)
>>
>
> Europe is not the US ... we have well over a thousand TV stations,
> of which probably a half are full-production capable,
> as opposed to you people who are almost all repeaters ...
> how many full TV stations with their own local production
> facilities are there in the UK?
>

All BBC and ITV stations have local news production, usually a small
multicamera studio with local editing, graphics, SNG/Microwave truck(s),
etc. Some ITV (Granada, LWT, Anglia, Scottish, UTV, Meridian) stations have
medium-large multicamera studios for network / regional production - though
some of these are closing.

The BBC have major stations in London (two centres - currently about 16 or
17 studios in the main one, Glasgow, Belfast and Glasgow)

Lots of studio shows are, these days, made in facilities studios - again
these are universally 16:9 digital.

I agree that the TV landscape is very different - but I am surprised at the
level of analogue 4:3 NTSC kit still in use in the US - I'd have though that
MCR/Presentation in some areas had moved to digital to use modern automation
systems - and this would allow an SDTV network show to be delivered to an
SDTV receiver with no analogue footprint, even if the local production
studios were still analogue.

>> Do Faroudja do interlace->interlace conversion (i.e. 50->100 or
>> 60->120?)
>
>
> I have no idea. It certainly is not what they are usually used
> for, which is 480@60i -> 480@60p conversion with 2:3 pulldown
> detection and fixup and full NTSC decoding (i.e. using
> both alternate lines and alternate frames, so-called "3D" ...
> which is not possible with PAL.)

What is your view of the PAL Transform decoder developed by BBC R&D - it is
a bit of a big beast but is a) reversible b) very high quality. BBC DVDs of
70s and 80s tubed studio stuff recorded onto 2" Quad and 1" C format all
look cracking when decoded via this system.

Steve
Anonymous
July 12, 2004 5:07:12 PM

Archived from groups: alt.video.digital-tv (More info?)

Stephen Neal wrote:

>
> Sorry - posting in the evening when tired and being a bit ambiguous.
>
> What I was trying to convey was that surely the difference in received HDTV
> (1080/60i, 720/60p) and SDTV (480/60i, 576/50i) resolution and colour space
> was only the spatial scaling - with 4:2:0 MPEG2 being used for both - and
> thus both having full-gamut component digital outputs at the domestic
> receiver.

Certainly digital OTA in the US is 4:2:0 MPEG2.


>This only being the case if the SDTV feed were derived from a
> digital feed that hasn't been through an NTSC or PAL analogue path.

Well, it certainly has not been through the un-recoverable
form of PAL. NTSC is a very different matter. Yes, some of it ...
in fact a lot of it ... probably has been through NTSC composite,
but NOT OTA NTSC composite: it probably was NTSC composite with
a full 1.5 MHz bandwith chroma in both I and Q. Even cheap consumer
grade chips do a fine job of recovering the full signal from this,
thanks to the brilliant design of NTSC which does not have
the hopelessly complicated phase shifts of PAL. In our town,
all the non-HD channels derive their digital signal from NTSC.
This is of course clearly nowhere near as good as what Fox
currently does, which is derive the digital from a top-grade
digital signal in which R, G, and B are all full resolution ...
truly 480x720 in all three.



>
> I accept what I think is your argument - that 4:2:2 480i scaled/upconverted
> to 4:2:2 equivalent 720p then coded to 4:2:0 equivalent 720p for TX will
> look better than 4:2:0 received MPEG2 480i scaled and upconverted to 720p
> 4:2:2 equivalent at home.

I'm not sure what 4:2:2 means ... what I am told Fox does is
send out digital in which all three channels are the full
480x720 resolution.


>>>
>>
>>Of course many stations are run analog these days.
>
>
> Ah - a major UK/US difference.

> In the UK the only 4:3
> analogue production left in the mainstream broadcast arena are really the
> BBC local TV News outfits, though some of these are now 16:9 digital.

Well, in the US the only 4:3 analog [note fix of spelling]
production left in the mainstream broadcast arena are really the
local TV outfits, which are not all necessarily news ... we have
a PBS station that does many, many hours a week of local non-news
production. I don't know if this PBS station is digital or not ...
they recently moved to a new plant, so I suspect it is. Our second
closest PBS station is definately converting to digital, and
apparently will have a modest News/sports truck that is HD
[for local production of college sports, hence the "modest".]

BUT ..... Local "News" is a huge, gigantic part of US TV production!


> Surely you can't get new analogue kit these days at a decent level though -
> so if you have to replace a local news gallery, or a small local production
> studio, you'd go SDTV rather than HD wouldn't you?
>

Well, in most cases yes, but in some markets there may simply
be no money .... if an analog camera, for example, dies, they's
just get a used unit or a pro-sumer type. All they money got
spent for the mandated DTV transmitter!





>>>Certainly all UK digital TV platforms are digital component (and
>>>almost all TV production these days is digital component - barring
>>>some local stuff)

But we in the US have scads and scads of "local", some of it
pretty low-budget.



>>and most set top boxes will output RGB analogue
>>>via their SCART connectors -
No STB in the US currently outputs RGB analog .... only
component analog. This is to keep, as far as possible,
a split between computer and TV equipment, to prevent
exonomies of scale. There are TV monitors that do
take computer RGB analog, however. Note that in the
US computer and TV DVI are different (though most certainly
not incompatible ... just enough different to be a nuisance.)


>
> I agree that the TV landscape is very different - but I am surprised at the
> level of analogue 4:3 NTSC kit still in use in the US - I'd have though that
> MCR/Presentation in some areas had moved to digital to use modern automation
> systems - and this would allow an SDTV network show to be delivered to an
> SDTV receiver with no analogue footprint, even if the local production
> studios were still analogue.

There is little point in that, except, previously, for Fox stations.
It's either go the cheapest possible route (convert analog
to digital AT THE TRANSMITTER BUILDING, post-analog-STL),
go full digital (though not HD production, just all digital
switching that is HD capable), or the intermediate step of
just enough digital to get a network HD feed to a switcher
that switches from an analog-digital convertor that is
after the entire pre-conversion local analog plant. Many
stations are doing the last.

>
> What is your view of the PAL Transform decoder developed by BBC R&D - it is
> a bit of a big beast but is a) reversible b) very high quality. BBC DVDs of
> 70s and 80s tubed studio stuff recorded onto 2" Quad and 1" C format all
> look cracking when decoded via this system.


My opinion is that your PAL was a serious silliness ... deployed
just as the "problem" it was supposed to cure became a non-issue,
just as your DAB was a mistake ... a SERIOUS mistake ... and
the higher bitrate parts of DVB-T are a mistake. MPEG-2 is
not, of course, a mistake compared of modern better stuff,
it is all there was and still there is no way to ensure
"upgradeability". When the TV does deploy a mobile-capable
STDV service, it will be with a better codec.

Doug McDonald
Anonymous
July 13, 2004 5:55:32 AM

Archived from groups: alt.video.digital-tv (More info?)

"Doug McDonald" <mcdonald@scs.uiuc.edu> wrote in message
news:ccu51m$of$1@news.ks.uiuc.edu...
> Stephen Neal wrote:
>
> >
> > Sorry - posting in the evening when tired and being a bit ambiguous.
> >
> > What I was trying to convey was that surely the difference in received
HDTV
> > (1080/60i, 720/60p) and SDTV (480/60i, 576/50i) resolution and colour
space
> > was only the spatial scaling - with 4:2:0 MPEG2 being used for both -
and
> > thus both having full-gamut component digital outputs at the domestic
> > receiver.
>
> Certainly digital OTA in the US is 4:2:0 MPEG2.

Yep - same as the UK.

>
>
> >This only being the case if the SDTV feed were derived from a
> > digital feed that hasn't been through an NTSC or PAL analogue path.
>
> Well, it certainly has not been through the un-recoverable
> form of PAL. NTSC is a very different matter. Yes, some of it ...
> in fact a lot of it ... probably has been through NTSC composite,
> but NOT OTA NTSC composite: it probably was NTSC composite with
> a full 1.5 MHz bandwith chroma in both I and Q. Even cheap consumer
> grade chips do a fine job of recovering the full signal from this,
> thanks to the brilliant design of NTSC which does not have
> the hopelessly complicated phase shifts of PAL.

Yep - but it still has the appalling chroma bandwith reduction, and inherent
limitations of sub-carrier based encoding (even S-video has most of these)
irrespective of it being PAL or NTSC.

I had imagined that more US SDTV stuff was free of composite artefacts - if
nothing else the inherent subcarrier artefacts that even high-quality
decoding suffers from means MPEG2 encoding is less efficient (as you are
encoding artefacts rather than picture detail)

> In our town,
> all the non-HD channels derive their digital signal from NTSC.

Ah - few of the DTV stations in mine have detectable composite artefacts (I
think Sky Sports News does) - certainly the main UK networks (BBC One, Two,
Three, Four, News 24, CBBC, CBeebies, ITV1, ITV2, Channel Four, Five)
don't - apart from on some news contributions that use legacy links gear.

> This is of course clearly nowhere near as good as what Fox
> currently does, which is derive the digital from a top-grade
> digital signal in which R, G, and B are all full resolution ...
> truly 480x720 in all three.

Surely 4:2:2 YCrCb is what Fox run isn't it? What VT format are they using
that runs 4:4:4 RGB rather than 4:2:2 YCrCb? (I know there was some
experimental D1 stuff running 4:4:4 SDTV - but I didn't think it was
mainstream) Standard SDTV SDI (i.e. 270Mbs) digital video used to connect
SDTV VTRs, Vision Mixers, cameras, still stores etc. runs on the basis of
4:2:2 sampling rather than 4:4:4 - where two interconnects are required
(which is normally limited to telecine ->colour corrector connection etc.)

>
> >
> > I accept what I think is your argument - that 4:2:2 480i
scaled/upconverted
> > to 4:2:2 equivalent 720p then coded to 4:2:0 equivalent 720p for TX will
> > look better than 4:2:0 received MPEG2 480i scaled and upconverted to
720p
> > 4:2:2 equivalent at home.
>
> I'm not sure what 4:2:2 means ... what I am told Fox does is
> send out digital in which all three channels are the full
> 480x720 resolution.

4:2:2 is the standard broadcast digital sampling structure used for SDTV
broadcast video. The RGB camera output is matrixed to Luminance (Y) and
Colour Difference Cr (R-Y) and Cb (B-Y) signals. The Luminance signal is
sampled at 13.5MHz, the Chrominance signals are both sampled at 6.75MHz -
i.e. there is twice as much luminance resolution horizontally than
chrominance. Therefore for every two luminance (Y) samples there is a single
pair of Cr (B-Y) and Cb (R-Y) samples - or in data terms one luma sample is
paired with a Cr sample, the next with a Cb (though the chroma samples are
deemed to be co-sited) The vertical chroma resolution is not reduced - and
remains the same as the luminance resolution. This gives a luminance
resolution of 720x480 or 720x576, and a chroma resolution of 360x480 or
360x576.

4:2:0 is used in some VT formats (miniDV) and for OTA MPEG2 SDTV
transmission. This works by halving the VERTICAL chroma resolution as well,
so that the chroma resolution is reduced equal horizontal and vertically
relative to the luminance resolution (reducing the bandwith requirement
noticably). Thus the luminance remains 720x480/576 but the chroma is
reduced to 360x240/288.

If the 480/60i to 720/60p conversion is done with a 4:2:2 480/60i source (as
would be the case at a broadcast centre) there is more vertical chroma
resolution to take advantage of (and fewer compression artefacts) than if
the conversion is done in the home where the 480/60i source is 4:2:0 and
thus has half the vertical chroma resolution.

Fox will still then be broadcasting the 720/60p in 4:2:0 (or the equivalent
scaled HD version - for some reason 4:2:0 is still often used rather than
16:8:0 or whatever the equivalent is) via MPEG2 and the resolutions would
thus be 1280x720 luminance, 640x360 for the chrominance. I don't see how
Fox can broadcast a 4:4:4 RGB signal over ATSC (I don't think the forms of
MPEG2 used allow 4:4:4 in either RGB or YCrCb chroma spaces), nor do I see
how they'd source the material in 4:4:4 720x480/60i using conventional
standard SDTV broadcast production kit.

> >>>
> >>
> >>Of course many stations are run analog these days.
> >
> >
> > Ah - a major UK/US difference.
>
> > In the UK the only 4:3
> > analogue production left in the mainstream broadcast arena are really
the
> > BBC local TV News outfits, though some of these are now 16:9 digital.
>
> Well, in the US the only 4:3 analog [note fix of spelling]

I'm happy for you to convert my TV programmes to your "programs" and my
analogue production to your "analog" - can't help spelling the way I was
brought up to though.

> production left in the mainstream broadcast arena are really the
> local TV outfits, which are not all necessarily news ... we have
> a PBS station that does many, many hours a week of local non-news
> production. I don't know if this PBS station is digital or not ...
> they recently moved to a new plant, so I suspect it is. Our second
> closest PBS station is definately converting to digital, and
> apparently will have a modest News/sports truck that is HD
> [for local production of college sports, hence the "modest".]
>
> BUT ..... Local "News" is a huge, gigantic part of US TV production!

Yep - less so in the UK - where the Network and Local Newscasts on both
channels are kind of more integrated and more national/international and
less local. (Our longest regional news bulletin is about 30 mins in the UK
on both BBC One and ITV1 - spread over about 17-25 regions. This directly
follows a networked national newscast - there is no tradition of local news
teams covering national stories - as national stories - in their
programmes - they leave that to the network shows unless there is a
different regional angle that it is relevant for them to cover.)

You are right - it is a major difference - the UK is a smaller country, and
its whole TV landscape is sculpted around national networks rather than
affiliates.

>
>
> > Surely you can't get new analogue kit these days at a decent level
though -
> > so if you have to replace a local news gallery, or a small local
production
> > studio, you'd go SDTV rather than HD wouldn't you?
> >
>
> Well, in most cases yes, but in some markets there may simply
> be no money .... if an analog camera, for example, dies, they's
> just get a used unit or a pro-sumer type. All they money got
> spent for the mandated DTV transmitter!

Yep - the price paid for lots of local TV stations is that they are
presumably less well-funded. That said many BBC English regions still
running 4:3 PAL analogue kit are using galleries built in the
late-80s/early-90s - two or three regions only ditched their last tubed
cameras for CCDs in the last couple of years, and the BBC is still using a
hell of a lot of analogue component Beta SP gear locally and nationally
(even for 16:9 production)

>
> >>>Certainly all UK digital TV platforms are digital component (and
> >>>almost all TV production these days is digital component - barring
> >>>some local stuff)
>
> But we in the US have scads and scads of "local", some of it
> pretty low-budget.

Yep - a major difference. I think our budget range is smaller than the US -
our local TV stations are probably less local, but better equipped, but our
high-end productions are probably lower budget to. The move to 16:9 SDTV
(which is now a large majority of all the major UK networks output) rather
than HDTV allowed a change-over earlier and more quickly - though I suspect
HDTV is coming quicker than many were expecting. A couple of French
networks have announced they are moving to MPEG4 based HD next year - having
already negotiated HD rights to their movies and imported shows already.

> >>and most set top boxes will output RGB analogue
> >>>via their SCART connectors -
> No STB in the US currently outputs RGB analog .... only
> component analog. This is to keep, as far as possible,
> a split between computer and TV equipment, to prevent
> exonomies of scale.

Ah - we've had RGB analogue since the early 80s - as part of the
Peritel/SCART standard. It initially came about to allow external monitors
(like the Sony Profeel) to be fed Videotext/Teletext in quality, and
analogue RGB (via SCART or DIN) was popular with 80s home computers that
used TVs as monitors. I fondly remember the move from UHF modulator to
Composite video and then RGB analogue with mine!

When DVD arrived almost universally players came with RGB output, as did set
top boxes for D/D2MAC analogue component satellite transmissions, and then
DVB boxes.

Although it is a horrible connector - it does have great benefits for user
simplicity. A single connector can carry composite video, stereo audio (in
two directions at the same time), as well as widescreen switching and status
switching. When used in RGB mode it becomes directional. It makes
connecting VCRs,DVD players and STBs to TVs pretty easy (my Mum can do it)
and a lot easier than the 5xRCA phonos required for analogue component (or
6xRCA phonos required for Composite+Stereo audio in and out for VCRs)

As a result the triple phono component analogue connection is less popular -
though is the defacto standard for PAL progressive interconnects - the rule
seems to be SCART = interlaced SDTV res, Component = progressive or HD.

> There are TV monitors that do
> take computer RGB analog, however. Note that in the
> US computer and TV DVI are different (though most certainly
> not incompatible ... just enough different to be a nuisance.)
>

Yep - not much DVI video stuff around in the UK yet - just the odd HDTV set
top box for the Euro 1080 broadcasts.

>
> >
> > I agree that the TV landscape is very different - but I am surprised at
the
> > level of analogue 4:3 NTSC kit still in use in the US - I'd have though
that
> > MCR/Presentation in some areas had moved to digital to use modern
automation
> > systems - and this would allow an SDTV network show to be delivered to
an
> > SDTV receiver with no analogue footprint, even if the local production
> > studios were still analogue.
>
> There is little point in that, except, previously, for Fox stations.
> It's either go the cheapest possible route (convert analog
> to digital AT THE TRANSMITTER BUILDING, post-analog-STL),
> go full digital (though not HD production, just all digital
> switching that is HD capable), or the intermediate step of
> just enough digital to get a network HD feed to a switcher
> that switches from an analog-digital convertor that is
> after the entire pre-conversion local analog plant. Many
> stations are doing the last.
>

However - surely there must be local TV stations that can't afford to go HD
for production but need to upgrade ailing analogue production kit? Surely a
move to SDTV would make sense for them? Certainly a lot of SDTV US sitcom
and drama looks to be produced SDTV rather than analogue NTSC - no composite
artefacts to be seen on standards conversions that make it over here (and
they don't get PAL footprints on the way to my TV!) - but I guess production
houses moved to digital a lot earlier than stations.

I think that SDTV production with HDTV digital presentation would make sense
to a lot of people - the improvement in SDTV relative to analogue NTSC in
production would still be marked - and SDTV upconverted to HD will look a
lot better than NTSC upconverted to HD.

The last suggestion is effectively what the BBC supplied all of their
analogue regional stations with when they launched regional output on the
DVB-T version of BBC One (until then a pan-UK "best of the local news" had
filled regional slots on the digital version of the network). All the
regions were given small SDTV switchers and Aspect Ratio Converters to allow
them to switch from the 16:9 SDTV network feed to a delayed-and-ARCed-to14:9
SDTV output from the 4:3 PAL analogue studio for the duration of the
regional show. (This is complicated by the need for a switch to also take
place on the separate analogue network feed, so a fixed video delay and
switch delay was introduced to the regional digital studio chain to
compensate for coding latency in the digital chain)

> >
> > What is your view of the PAL Transform decoder developed by BBC R&D - it
is
> > a bit of a big beast but is a) reversible b) very high quality. BBC
DVDs of
> > 70s and 80s tubed studio stuff recorded onto 2" Quad and 1" C format all
> > look cracking when decoded via this system.
>
> My opinion is that your PAL was a serious silliness ... deployed
> just as the "problem" it was supposed to cure became a non-issue,
> just as your DAB was a mistake ... a SERIOUS mistake ... and
> the higher bitrate parts of DVB-T are a mistake.

Can't agree there - PAL was a very effective compromise that has served
Europe incredibly well. The BBC recently showed some of their early
Wimbledon coverage - 67,68 etc. - and it stands up incredibly well to
today's stuff. The US NTSC stuff I have seen from the same era doesn't hold
up as well - but it is difficult to say if this is a problem with NTSC per
se or the cameras (which seemed to be based on Image Orthicons and/or
Vidicons rather than Plumbicons)

But we always differ on this point. I think we were lucky to chose a wider
channel spacing in Europe that allowed a wider luminance bandwith (and a
higher chroma subcarrier to be used) - but that is not a PAL issue (we could
have run NTSC 4.43 as the BBC initially envisaged) but the more robust
nature of PAL did pay big dividends. I think we benefited in the early days
because cameras designed for PAL had to be sharper (again not because they
were PAL but because PAL meant wider bandwith effectively), and were often
better engineered than the cameras engineered for NTSC. Certainly in the
70s Philips, Fernseh, Link and Marconi cameras seemed to do better than RCAs
in the picture quality stakes in Europe. (I think the European manufacturers
also started later in the design stakes, so were selling devices based on
more modern technology)

NTSC may be easier to decode - but it is also easier to mangle in a
distribution and transmission chain. The average NTSC OTA or NTSC cable
picture I have seen when visiting the US has, sadly, always been softer and
of far poorer colour quality (not sure if this is IQ vs UV processing, or
the use of autotint type hue-tracking controls) than the PAL picture in
equivalent situations. (And I don't mean hotel rooms - their TV pictures are
normally lousy the world over...)

NTSC analogue (and composite digital) as a production format is much
better - and you are right, when well looked after it delivers good
pictures. Problem is it is often not well looked after. 720x480i digital
production is excellent - and apart from the coarser line structure
(especially noticable on letterboxed 16:9 material) - not an issue.

The pictures delivered by a PAL transform decoder do look cracking when
viewed from DVD - I don't have access to equivalent NTSC video from the same
time zone - with the exception of the PBS Cosmos DVDs - which also look very
good (though a good bit softer)

> MPEG-2 is
> not, of course, a mistake compared of modern better stuff,
> it is all there was and still there is no way to ensure
> "upgradeability". When the TV does deploy a mobile-capable
> STDV service, it will be with a better codec.

Looks like a DVB-T receiver for mobile use is about to appear on the German
market - tests show it received all 21 channels on their DTT system (which
runs at a lower data rate in narrower channels than the UKs, but is similar)

Steve
Anonymous
July 28, 2004 7:41:02 PM

Archived from groups: alt.video.digital-tv (More info?)

Stephen Neal wrote:

>>Well, it certainly has not been through the un-recoverable
>>form of PAL. NTSC is a very different matter. Yes, some of it ...
>>in fact a lot of it ... probably has been through NTSC composite,
>>but NOT OTA NTSC composite: it probably was NTSC composite with
>>a full 1.5 MHz bandwith chroma in both I and Q.


> Yep - but it still has the appalling chroma bandwith reduction,

As I said, not necessarily. Non-broadcast NTSC may have
a full 1.5 MHZ in both sidebands of I and Q.


> and inherent
> limitations of sub-carrier based encoding (even S-video has most of these)
> irrespective of it being PAL or NTSC.

S-video subcarrier encoding has no significant limitations,
even with a 3.58 MHz subcarrier. 3 MHz color bandwidth
in both I and Q is just fine for even a 7 MHz luma.


>
> I had imagined that more US SDTV stuff was free of composite artefacts - if
> nothing else the inherent subcarrier artefacts that even high-quality
> decoding suffers from means MPEG2 encoding is less efficient (as you are
> encoding artefacts rather than picture detail)
>

High quality decoding of even composite NTSC is very, very good
indeed, if it is not OTA bandwidth limited. Indeed,
for static pictures it it essentially a perfect decode.


>
>>In our town,
>>all the non-HD channels derive their digital signal from NTSC.
>
>
> Ah - few of the DTV stations in mine have detectable composite artefacts (I
> think Sky Sports News does) - certainly the main UK networks (BBC One, Two,
> Three, Four, News 24, CBBC, CBeebies, ITV1, ITV2, Channel Four, Five)
> don't - apart from on some news contributions that use legacy links gear.
>
>
>>This is of course clearly nowhere near as good as what Fox
>>currently does, which is derive the digital from a top-grade
>>digital signal in which R, G, and B are all full resolution ...
>>truly 480x720 in all three.
>
>


>>
>>I'm not sure what 4:2:2 means ... what I am told Fox does is
>>send out digital in which all three channels are the full
>>480x720 resolution.
>
>
> 4:2:2 is the standard broadcast digital sampling structure used for SDTV
> broadcast video. The RGB camera output is matrixed to Luminance (Y) and
> Colour Difference Cr (R-Y) and Cb (B-Y) signals. ..... [snip] This gives a luminance
> resolution of 720x480 or 720x576, and a chroma resolution of 360x480 or
> 360x576.
>
>
> Fox will still then be broadcasting the 720/60p in 4:2:0

There is zero doubt about that: you are correct.

> I don't see how
> Fox can broadcast a 4:4:4 RGB signal over ATSC
They don;t


>nor do I see
> how they'd source the material in 4:4:4 720x480/60i using conventional
> standard SDTV broadcast production kit.

They don't, I am told. The only high resolution stuff
is telecines 35 mm 24 Hz film. Sometimes they do
upconvert true TV camera video for sports, and the result is
horrible.



Doug
Anonymous
July 29, 2004 8:06:28 AM

Archived from groups: alt.video.digital-tv (More info?)

In article <ce9312$oqv$1@news.ks.uiuc.edu>,
Doug McDonald <mcdonald@scs.uiuc.edu> writes:
> Stephen Neal wrote:
>
>>>Well, it certainly has not been through the un-recoverable
>>>form of PAL. NTSC is a very different matter. Yes, some of it ...
>>>in fact a lot of it ... probably has been through NTSC composite,
>>>but NOT OTA NTSC composite: it probably was NTSC composite with
>>>a full 1.5 MHz bandwith chroma in both I and Q.
>
>
>> Yep - but it still has the appalling chroma bandwith reduction,
>
> As I said, not necessarily. Non-broadcast NTSC may have
> a full 1.5 MHZ in both sidebands of I and Q.
>
The effect of the I and Q bandwidth reduction isn't quite as
severe as it might superficially appear to be. The axis(sp) are
well chosen. Considering the technology of the day, they did
a wonderful job of packing video into a small place. :-).

>>
>> I had imagined that more US SDTV stuff was free of composite artefacts - if
>> nothing else the inherent subcarrier artefacts that even high-quality
>> decoding suffers from means MPEG2 encoding is less efficient (as you are
>> encoding artefacts rather than picture detail)
>>
>
> High quality decoding of even composite NTSC is very, very good
> indeed, if it is not OTA bandwidth limited. Indeed,
> for static pictures it it essentially a perfect decode.
>
One other thing:

The technology needed to do a full NTSC decode is significantly
different from the typical PAL decoder. This means that PAL TV
sets that also do an NTSC decode (with the fancy multi-line LINE-COMBS)
cannot really do justice when compared with a full NTSC comb. The
line-comb is a BACKUP DECODING MODE for significant movement when
compared to the very good 3D combing. It is interesting when looking
at the effects of full 3D decode when compared with almost any line
comb. The diagonal resolution is nearly perfect with a 3D decode.

>
> They don't, I am told. The only high resolution stuff
> is telecines 35 mm 24 Hz film. Sometimes they do
> upconvert true TV camera video for sports, and the result is
> horrible.
>
Yes -- the Fox sports stuff looks incredibly horrendous. Superficially
(because I haven't checked carefully), the image looks WORSE than
a proper NTSC sports broadcast. (At least with my own 3d comb
decoders.)

For someone who has never seen a good 3D comb (which I know that you
have), it is difficult to explain how well they can actually work.

There are differing levels of performance, and even some cases where
a 3D comb can look WORSE than a good 2D comb.

John
Anonymous
August 4, 2004 9:08:54 PM

Archived from groups: alt.video.digital-tv (More info?)

In article <ccu51m$of$1@news.ks.uiuc.edu>, mcdonald@scs.uiuc.edu says...

>No STB in the US currently outputs RGB analog .... only
>component analog.

True, but only because of a technicality. The RCA DTC-100, which was the first
(and, to this day, probably the least troublesome and buggy) OTA/DirecTV high
definition set-top box had a VGA RGB output for high definition. It had no
component output. The technicality that saves your statement: the DTC-100 is
now discontinued.
Anonymous
August 5, 2004 1:40:41 AM

Archived from groups: alt.video.digital-tv (More info?)

Robert Orban wrote:
> In article <ccu51m$of$1@news.ks.uiuc.edu>, mcdonald@scs.uiuc.edu says...
>
>
>>No STB in the US currently outputs RGB analog .... only
>>component analog.
>
>
> True, but only because of a technicality. The RCA DTC-100, which was the first
> (and, to this day, probably the least troublesome and buggy) OTA/DirecTV high
> definition set-top box had a VGA RGB output for high definition. It had no
> component output. The technicality that saves your statement: the DTC-100 is
> now discontinued.
>

The Samsung T-150 also had an RGB output ... and it too
is long discontinued. That's why I said "currently".

Doug McDonald
!