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From: Sabrina Kilian
Subject: Re: HDMI cable confusion/paranoia
Date: 5 Mar 2010 17:34:00
Message: <4b9186d8$1@news.povray.org>
Jeremy "UncleHoot" Praay wrote:
> There it is.  Let me know if I'm wrong.  I can't believe that I could be 
> right about all of this stuff, as there seem to be so many people out there 
> who seem to think I'm wrong. 

You seem to have encountered the High-Def equivalent of extreme
audiophiles. You can find the same people buying CD/DVD/Blue-ray
de-magnetizers, because it makes the sound/image quality better. Or
wooden knobs for their amps, for the tonal quality. Or acoustic rocks,
after-market power cords infused with nitrogen, R-Type stickers that
make their cars go faster . . . wait, slipped off topic for a bit there.

All said, there can be a difference in cable quality. I would not try
pushing 10Gbps ethernet over cat5 cable for any distance. HDMI, if it
were supporting 1080p, 60 Hz frame rate, 12 bit per color with no
compression, would have to support a data rate close to 4.5 Gbps. (G is
SI, not 1024M here). I don't think I would try sending that over
unfolded cloths hangers wrapped together with gaffers tape. But, for the
normally short distances between a TV and other components, just about
any braided copper wire will do, if properly shielded from cross-talk
and such which, I would think, the HDMI standard should cover. If you
get problems between two components then you can look at just those
cables involved, and figure out if they are really bad cables or if the
components need a better cable to communicate over.

For 120Hz, and now 240Hz, some (most?) of those TVs blend frames
together, to blur the change between each frame. Watching the
side-by-side demos in stores hasn't impressed me too much, maybe because
the compression artifacts are so pronounced when you stand that close to
these big TVs. Maybe when 3D becomes more used, I will check them out again.


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From: Darren New
Subject: Re: HDMI cable confusion/paranoia
Date: 5 Mar 2010 18:31:21
Message: <4b919449$1@news.povray.org>
Sabrina Kilian wrote:
> the compression artifacts are so pronounced when you stand that close to
> these big TVs. 

You know, I used to think that.  I used to work on compression algorithms, 
so I got really good at seeing the kind of artifacts that jpeg and mpeg 
produce. Every time I went in the store and looked at the HDTV, I saw all 
the compression artifacts in the background and thought 'wow, that sucks.'

Then my TV died, so we bought a big-screen LCD TV. The difference between 
the SD channels on cable and the HD channels on cable is stunning. Stadium 
crowds that used to look like a Monet painting now all have faces and stuff 
even in the background. You can see grass blades. Etc.

Yes, the compression artifacts are still there, but they're *still* smaller 
than the analog blurring and color drift artifacts on a TV set that size. :-)

-- 
Darren New, San Diego CA, USA (PST)
   The question in today's corporate environment is not
   so much "what color is your parachute?" as it is
   "what color is your nose?"


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From: Sabrina Kilian
Subject: Re: HDMI cable confusion/paranoia
Date: 5 Mar 2010 22:14:24
Message: <4b91c890@news.povray.org>
Darren New wrote:
> Sabrina Kilian wrote:
>> the compression artifacts are so pronounced when you stand that close to
>> these big TVs. 
> 
> You know, I used to think that.  I used to work on compression
> algorithms, so I got really good at seeing the kind of artifacts that
> jpeg and mpeg produce. Every time I went in the store and looked at the
> HDTV, I saw all the compression artifacts in the background and thought
> 'wow, that sucks.'
>

I could ignore them on my old small TV, when cable started
rebroadcasting very compressed signals. Now I have a large 1080p tv, but
I get programing over the air, so the local news and such comes in very
clear while other programing varies.

> Then my TV died, so we bought a big-screen LCD TV. The difference
> between the SD channels on cable and the HD channels on cable is
> stunning. Stadium crowds that used to look like a Monet painting now all
> have faces and stuff even in the background. You can see grass blades. Etc.
> 
> Yes, the compression artifacts are still there, but they're *still*
> smaller than the analog blurring and color drift artifacts on a TV set
> that size. :-)
> 

Oh, yeah. It's the angle the they have you viewing the TVs at in stores
that make the difference. I am not likely to watch the tele from 1 foot
away, nor from 6 feet under the box staring up a wall at it. It benefits
the high end TVs that do some filtering, which I suspect all have a
higher margin for the stores.


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From: UncleHoot
Subject: Re: HDMI cable confusion/paranoia
Date: 5 Mar 2010 22:56:38
Message: <4b91d276@news.povray.org>
"Darren New" <dne### [at] sanrrcom> wrote in message 
news:4b919449$1@news.povray.org...
> Sabrina Kilian wrote:
>> the compression artifacts are so pronounced when you stand that close to
>> these big TVs.
>
> You know, I used to think that.  I used to work on compression algorithms, 
> so I got really good at seeing the kind of artifacts that jpeg and mpeg 
> produce. Every time I went in the store and looked at the HDTV, I saw all 
> the compression artifacts in the background and thought 'wow, that sucks.'

I'm not sure if it's just the Walmart in my neighborhood, or if all of them 
are like this, but they have lots and lots of TV's all running the same 
signal, and their TV's look like crap.  For one thing, most (if not all) are 
using shared analog connections of some kind.  Plus, the demo they have 
running has TONS of compression artifacts in it.  Any time the on-screen 
text should look clear and crisp, it looks like an awful, lossy JPEG.  It 
certainly doesn't impress.

Ironically, that's where I bought my TV.  :-)


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From: UncleHoot
Subject: Re: HDMI cable confusion/paranoia
Date: 5 Mar 2010 22:59:31
Message: <4b91d323$1@news.povray.org>
"Sabrina Kilian" <ski### [at] vtedu> wrote in message 
news:4b91c890@news.povray.org...
> Darren New wrote:
>> Sabrina Kilian wrote:
>>> the compression artifacts are so pronounced when you stand that close to
>>> these big TVs.
>>
>> You know, I used to think that.  I used to work on compression
>> algorithms, so I got really good at seeing the kind of artifacts that
>> jpeg and mpeg produce. Every time I went in the store and looked at the
>> HDTV, I saw all the compression artifacts in the background and thought
>> 'wow, that sucks.'
>
> I could ignore them on my old small TV, when cable started
> rebroadcasting very compressed signals. Now I have a large 1080p tv, but
> I get programing over the air, so the local news and such comes in very
> clear while other programing varies.
>

Digital compression on my old 27" TV bothered me, but I guess I could handle 
it.   Once we got the 46" screen, it was painful to watch.  Generally 
speaking, I only watch the HD channels now, and by and large, they look 
pretty good.  (DISH Network)


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From: Orchid XP v8
Subject: Re: HDMI cable confusion/paranoia
Date: 6 Mar 2010 05:19:09
Message: <4b922c1d$1@news.povray.org>
> It's the same reason you can only get ADSL service at certain distances 
> from the telco CO. It's an analog signal. It's only digital once it gets 
> inside your computer.

ADSL is a digital signal modulated into an analogue one. (And carried 
over cables supplied by the lowest bidder, specified to carry voice data 
only, at the minimum quality level necessary for it to be vaguely 
comprehendable.) HDMI is a raw, unmodulated digital signal.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*


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From: Orchid XP v8
Subject: Re: HDMI cable confusion/paranoia
Date: 6 Mar 2010 05:24:51
Message: <4b922d73@news.povray.org>
Darren New wrote:
> Sabrina Kilian wrote:
>> the compression artifacts are so pronounced when you stand that close to
>> these big TVs. 
> 
> You know, I used to think that.  I used to work on compression 
> algorithms, so I got really good at seeing the kind of artifacts that 
> jpeg and mpeg produce. Every time I went in the store and looked at the 
> HDTV, I saw all the compression artifacts in the background and thought 
> 'wow, that sucks.'
> 
> Then my TV died, so we bought a big-screen LCD TV. The difference 
> between the SD channels on cable and the HD channels on cable is 
> stunning. Stadium crowds that used to look like a Monet painting now all 
> have faces and stuff even in the background. You can see grass blades. Etc.
> 
> Yes, the compression artifacts are still there, but they're *still* 
> smaller than the analog blurring and color drift artifacts on a TV set 
> that size. :-)

Well, let me see now.

On my mum's old CRT TV, there was really no noticable difference between 
analogue and digital. Both looked equally fuzzy.

(I once plugged my laptop into the TV, and even if I set the resolution 
absurdly low and made all the fonts huge, they were unreadable.)

Now my mum has this shiny new LCD TV. And suddenly digital looks 
*awful*! As soon as anything moves faster than 2 MPH, it's blocky and 
unrecognisible. Although... it seems to vary by channel somewhat.

(And that of course is the other undesirable thing about digital TV. 
There used to be, like, 5 channels, 4 of them containing high quality 
programming. Now there's 500 channels and they're *all* showing utter 
crap that nobody would ever want to watch...)

I've only seen HD stuff in shops, but from what I can tell, there's no 
visible difference between HD and SD. If I ever get time to set up my 
mum's new BluRay player, maybe I can test for myself. But seriously, 
everybody's going on like it fundamentally transforms your viewing 
experience. But it's only 4x the resolution. Not 40x or 400x, just 4x. 
And, from what I've seen, this equals to a slight increase in constrast, 
and not much else.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*


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From: Darren New
Subject: Re: HDMI cable confusion/paranoia
Date: 6 Mar 2010 11:57:14
Message: <4b92896a@news.povray.org>
Orchid XP v8 wrote:
> HDMI is a raw, unmodulated digital signal.

There is no such thing. Digital is your imagination.

-- 
Darren New, San Diego CA, USA (PST)
   The question in today's corporate environment is not
   so much "what color is your parachute?" as it is
   "what color is your nose?"


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From: Darren New
Subject: Re: HDMI cable confusion/paranoia
Date: 6 Mar 2010 12:00:41
Message: <4b928a39$1@news.povray.org>
Orchid XP v8 wrote:
> I've only seen HD stuff in shops, but from what I can tell, there's no 
> visible difference between HD and SD.

That's exactly what I'm talking about. There's really a tremendous 
difference, but you have to notice it by switching back and forth between HD 
and SD.

It's like playing a game with all the graphics turned up, vs playing in 256 
colors at 640x480.

> If I ever get time to set up my 
> mum's new BluRay player, maybe I can test for myself. 

I do like bluray better than hddvd. I'm glad they won. I prefer the 
speckly-dithering to the blocky compression, especially at more than a foot 
from the screen.

> everybody's going on like it fundamentally transforms your viewing 
> experience. But it's only 4x the resolution.

And digital, meaning no blur or color smear.

-- 
Darren New, San Diego CA, USA (PST)
   The question in today's corporate environment is not
   so much "what color is your parachute?" as it is
   "what color is your nose?"


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From: Orchid XP v8
Subject: Re: HDMI cable confusion/paranoia
Date: 6 Mar 2010 12:23:54
Message: <4b928faa$1@news.povray.org>
>> HDMI is a raw, unmodulated digital signal.
> 
> There is no such thing. Digital is your imagination.

There's a big difference between recognising a DC signal, and 
recognising a sine tone with a specific frequency.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*


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