How Does Digital Video Work?

D

David Lloyd-Jones

Guest
We learned in skule how a TV set works: a flying beam rasters down the
screen, energizing phosphors on the back of the glass; different
phosphors for different colors; higher energy beam for brighter
spots...

Where could I find an explanation at roughly this level of generality
of how video cards and digital "screens" work? How does a photograph,
or a data-base of X-million numerical values, get turned into a
picture on a plasma screen? A Jumbotron? The outside of the NASDAQ
building in Times Square?

I've Googled like crazy around this question, but end up swamped with
stuff about what is the best video card for your gaming fun. "How-to"
searches get me how to put in a video card. Still, Google pointers
would be handy.

TIA,

-dlj.
 
"David Lloyd-Jones" <EnviroLED@hotmail.com> wrote in message
news:7f3dcfa9.0402191352.4ac8559d@posting.google.com...

Where could I find an explanation at roughly this level of generality
of how video cards and digital "screens" work? How does a photograph,
or a data-base of X-million numerical values, get turned into a
picture on a plasma screen? A Jumbotron? The outside of the NASDAQ
building in Times Square?
Click to expand...
I don't know quite what level of detail you want, but there are
any number of texts that cover the operation of the various
non-CRT display technologies (few of which, by the way, are
truly "digital" - LCDs AREN'T, for instance). I could even,
at the risk of putting in a plug here, point you to my own book:

Display Interfaces: Fundamentals and Standards

.... published as part of the SID/Wiley Display Technology
series by John Wiley & Sons. But there are certainly a lot of
other sources, too.

Bob M.

I've Googled like crazy around this question, but end up swamped with
stuff about what is the best video card for your gaming fun. "How-to"
searches get me how to put in a video card. Still, Google pointers
would be handy.

TIA,

-dlj.
Click to expand...
 
On 19 Feb 2004 13:52:24 -0800, EnviroLED@hotmail.com (David
Lloyd-Jones) wrote:

We learned in skule how a TV set works: a flying beam rasters down the
screen, energizing phosphors on the back of the glass; different
phosphors for different colors; higher energy beam for brighter
spots...

Where could I find an explanation at roughly this level of generality
of how video cards and digital "screens" work? How does a photograph,
or a data-base of X-million numerical values, get turned into a
picture on a plasma screen? A Jumbotron? The outside of the NASDAQ
building in Times Square?

I've Googled like crazy around this question, but end up swamped with
stuff about what is the best video card for your gaming fun. "How-to"
searches get me how to put in a video card. Still, Google pointers
would be handy.

TIA,

-dlj.
Click to expand...
Did you try here? There may be something...

http://www.howstuffworks.com/

Tom
 
David Lloyd-Jones wrote:
We learned in skule how a TV set works:
Click to expand...
Where are you from?
Do they teach conventional English spelling?
 
David Lloyd-Jones wrote:
We learned in skule how a TV set works: a flying beam rasters down the
screen, energizing phosphors on the back of the glass; different
phosphors for different colors; higher energy beam for brighter
spots...

Where could I find an explanation at roughly this level of generality
of how video cards
----------------------
Click to expand...
A video card is a bank of RAM that is dual-port, it can be read from
and written to at the same time, or just RAM that can be written to
and read from alternately fast enough, to be used by a video generator
chip, or a set of counters and logic, to assemble the typical NTSC or
other kinds of video streams and route them to one or several outputs
for multiple colors.


and digital "screens" work? How does a photograph,
or a data-base of X-million numerical values, get turned into a
picture on a plasma screen? A Jumbotron? The outside of the NASDAQ
building in Times Square?
-dlj.
-------------------------
Click to expand...
The general process is the similar raster process, you scan a pixel
and then a line at a time, using decoder/demultiplexers and counters.

A photo gets digitized by sensing color and intensity in a region and
then approximating it as a single pixel of a specific intensity and
color balance of red, green and blue.

The multi-CRT over-large TV "walls" use counters to count pixels and
lines, and arrange to extraploate/interpolate pixel reductions or
expansions, often using dithering and other focal info-tricks and
route them to the correct new re-assembled video to each separate
monitor.

The purely pixel-field digital screens use a memory "backing" for the
emitter plane, and it writes to that memory to refresh to the new
image, some schemes blank it, some do not, or use more bit-tricks to
avoid ripple and aliasing.

Scrolling signs are merely demuxed addressing with latches or
shift-registers feeding LEDs
-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
On 19 Feb 2004 13:52:24 -0800, EnviroLED@hotmail.com (David
Lloyd-Jones) wrote:

We learned in skule how a TV set works: a flying beam rasters down the
screen, energizing phosphors on the back of the glass; different
phosphors for different colors; higher energy beam for brighter
spots...

Where could I find an explanation at roughly this level of generality
of how video cards and digital "screens" work? How does a photograph,
or a data-base of X-million numerical values, get turned into a
picture on a plasma screen? A Jumbotron? The outside of the NASDAQ
building in Times Square?

I've Googled like crazy around this question, but end up swamped with
stuff about what is the best video card for your gaming fun. "How-to"
searches get me how to put in a video card. Still, Google pointers
would be handy.

TIA,

-dlj.
Click to expand...
http://www.pctechguide.com/sitemap.htm
 
Ah yes skule. I remumble it woll.



"David Lloyd-Jones" <EnviroLED@hotmail.com> wrote in message
news:7f3dcfa9.0402191352.4ac8559d@posting.google.com...
We learned in skule how a TV set works: a flying beam rasters down the
screen, energizing phosphors on the back of the glass; different
phosphors for different colors; higher energy beam for brighter
spots...

Where could I find an explanation at roughly this level of generality
of how video cards and digital "screens" work? How does a photograph,
or a data-base of X-million numerical values, get turned into a
picture on a plasma screen? A Jumbotron? The outside of the NASDAQ
building in Times Square?

I've Googled like crazy around this question, but end up swamped with
stuff about what is the best video card for your gaming fun. "How-to"
searches get me how to put in a video card. Still, Google pointers
would be handy.

TIA,

-dlj.
Click to expand...
 
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