ricep5
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| reply to tschmidt
Re: Our way or the highway
I am well aware of the benefits of progressive over interlacing. I was merely stating when things got hairy on the ATSC.
There were other agendas in play other than the progressive stuff, sub-channeling rights, cost of conversions, bandwidth issues, technical issues with 8VSB.
It's a miracle the thing got off the ground at all.
In all, technology advances overcame most of the political agendas. It has become extremely flexible in some areas and has left alot to creativity. We won't recognize it 20 years from now from what we have today. |
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tschmidt
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| reply to ricep5
said by ricep5  :It was really simple, 480p for NTSC upconversion and 1080i for the higher def programming. I assume you are aware there are a number of significant shortcomings to using Interlace as opposed to progressive scanning.
NTSC is not progressive it is interlace to address 1930's vintage technology.
/tom |
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ricep5
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| reply to KrK
ATSC was actually moving along quite well until Microsoft stuck their nose in it (late) and starting pushing 720p with ABC in tow.
It was really simple, 480p for NTSC upconversion and 1080i for the higher def programming.
Then MS pushed this "must be seen on a computer" mentality and it really went bonkers after that. The arguments ended up getting irrational so ATSC just said "any resolution is acceptable" which turned it into the wild west. |
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Dogfather
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3 edits | reply to MxxCon
ITU-R BT.500
»www.dii.unisi.it/~menegaz/Doctor···0-11.pdf
My guess is that the MPEG group would follow this recommended methodology as other engineers and researchers would. |
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Dogfather
Premium
join:2007-12-26
Laguna Hills, CA | reply to MxxCon
That is part of what a standard would determine...at what point are they considered different. |
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MxxCon
join:1999-11-19
Brooklyn, NY
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| reply to PDXPLT
said by PDXPLT :There are ITU and MPEG standards for making objective measurements that correlate to perceived image quality. show me
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Check out my awesome city of MxxTopia »mxxtopia.myminicity.com/ind or »mxxtopia.myminicity.com (the more people visit, the bigger it is) |
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PDXPLT
join:2003-12-04
Banks, OR
1 edit | reply to MxxCon
said by MxxCon :The problem with such rule is there is no standard measurable unit of image "quality" Not true.
There are ITU and MPEG standards for making objective measurements that correlate to perceived image quality.
And as for other "HDTV standards", there are whole volumes of ATSC and MPEG standards for modulation, coding, and transmission of HDTV signals.
The title of this article is the problem. There are plenty of HDTV standards, including those for objective quality measurement.
What there aren't any of are HDTV quality regulations. There's no law that that states what image quality providers must broadbast, other than an ambiguous one that says at least one prgram equivalent to NTSC quality must be provided.
Broadcasters, cable MSO's, and DBS providers believe most consumers don't know and don't care about pciture quality. They're probably right; how many TV's are horribly misadjusted? Most of them. The providers believe they'll be more profitable providing quantity over quality. So they pack in as many overcompressed channels as they can.
The one place you may get relief from this is Blu-Ray. There is no economic incentive to compress more than what is necessary to fit on the disk. And the folks controlling the compression are the same who produced the film, and have an interest in having its quality preserved and displayed. |
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MxxCon
join:1999-11-19
Brooklyn, NY
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| reply to sporkme
said by sporkme :Take the original, zoom in to some number of pixels. Do the same on the compressed version. Count how many pixels are different. You can do this experiment at home. Take a high quality jpg. Save it with really crappy compression settings. Open up both. Zoom in to a complex area of the image. Count the pixels that are different. that kind of testing goes exactly against the way lossy video and audio compression works.
you try to throw away as much data as possible while trying to keep it perceptually identical TO HUMANS.
so at which point will you consider 2 pixels different? how would you know if some different pixels are important in an image or not?
would you want to waste video bandwidth trying to preserve details of a perfectly black sky with a few pixels being one shade brighter? or would you rather use it somewhere more obvious? |
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EPS
join:2008-02-13
Hingham, MA | reply to sporkme
But what is "different"? If a shade of red is slightly changed, is that equal to the shade of red getting blurred into gray? |
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sporkme
drop the crantini and move it, sister
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| reply to MxxCon
said by MxxCon :The problem with such rule is there is no standard measurable unit of image "quality". There certainly good be though. Take the original, zoom in to some number of pixels. Do the same on the compressed version. Count how many pixels are different.
You can do this experiment at home. Take a high quality jpg. Save it with really crappy compression settings. Open up both. Zoom in to a complex area of the image. Count the pixels that are different. |
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MxxCon
join:1999-11-19
Brooklyn, NY
clubs:
| reply to Da Man
18Mbps for 1080i != quality
The problem with such rule is there is no standard measurable unit of image "quality".
bitrate means nothing if codec doesn't know how to properly utilize it. while at the same time quality codec can encode superior image at smaller bitrate.
Just look at "megapixels" in digital cameras. |
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james
join:2001-02-26
antarctica
| reply to Da Man
He made a good point, you on the other hand are just being a smart ass. Perhaps 18Mbps being required for 1080i would cause a company who has been working on a superior compression technique to not support the new standard? Perhaps the new standard that is being negotiated would define MORE than how much bandwidth is to be used for a given resolution. |
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Da Man
join:2008-05-08
Hanover, PA | reply to KrK
Because requiring 18Mbps for 1080i to qualify as HD is patentable. |
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KrK
Heavy Artillery For The Little Guy
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| The reason why these standards are so hard to get defined and in place is because the various equipment manufacturers patent everything and then try and get the standard defined as to something they own patents over--- IE they try to basically own the market before it even exists.
This is why these standards often takes years and years and years of squabbling and protracted "discussions" and so on and so forth and little often gets done.
The only way to get a standard quickly adopted methinks is if it was royalty free--- ie manufacturers, broadcasters, etc etc couldn't be hit up for money for going with a standard. Problem is I doubt any of the interests involved want to give up THEIR patents or IP on these issues...
... and so thus, there we are.
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"Regulatory capitalism is when companies invest in lawyers, lobbyists, and politicians, instead of plant, people, and customer service." - former FCC Chairman William Kennard (A real FCC Chairman, unlike the current Corporate Spokesperson in the job!) |
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