Dee:

You don't understand binary compression techniques, ok...

.... it all has to do with binary trees (well, mostly, kind of), in
software, of the data stream, multiple bytes are converted into "data
streams", i.e., a pixel "byte" at this level is NOT necessarily 8 bits
long in a stream, and sometimes can be represented by a single bit
(automatic compression to 1/8 size just because it is stored in a
binary tree! (or, data stream) multiple occurring bytes can be sent in
the form of (five of these) or ((67 - number of bytes) of (00100100
- binary data byte to create 67 of)), in other words you tell it how
many of ONE type of data to create on the other end to fill in the
"video hole" on the screen, I would think you can visualize how small
a simple BW image can be transmitted--it grows bigger with grayscale
data, and much bigger with color data (in quality pictures an extra
few bits have to be sent just to describe the color/brightness of the
pixel being sent...)

.... there is also "variable bit rate compression" which I don't even
want to begin to try to give a simplified explanation of here...

I am sorry, my ability to describe these complex methods at work here
is lacking, and I realize this...
don't trust me on it, the web is loaded with papers on every aspect of
it...

The size of compressed data? That depends on the data types
compressed, BW video can be 90%+ compressed (resulting in data 1/10 to
1/20 the size, or MORE, it all just depends on the complexity of the
image.) For example, a completely white frame would be (for example)
1,024,000 bytes of color 00000000--this whole screen could be
transmitted in TWO BYTES!
and the same for an all black screen, at EXTREME RESOLUTION in this
simplified case.

Further "compression" can be had down at the hardware level where the
transmission software can "scan" data and "table-ize" streams of
duplicate bytes, or very similar bytes which can all be represented by
a common value with little or no detectable loss in "realized visual
quality." (can you really tell almost-almost black from "real" black?
Or, almost-almost-blue from "real" blue?)

In a very efficient compression scheme, it can be "mentally modeled"
as a onion, where many "layers" of compression are occurring in a
tight sequential loop creating very tightly compressed data packets,
with crc sums to ensure no data corruption and packets sequentially
numbered to provide a "sane" display stream (this can frequently be
rather lax with low quality audio (speech) and less than absolute
perfect video.)

Digital cell phones use very similar techniques on audio. Some of the
"trade secrets" there are closely protected...

It is really beyond the resources we have here to go into a deep
explanation on data compression techniques, and cheap tricks and short
cuts--a good book on the subject should bring one up to speed
quickly--perhaps amazon.com for those with a desire for a in-depth
understanding...

Now some "cheap tricks" examples:

you can actually throw away every other pixel (immediately cut the
size of a video frame in half!) by using a "normalized" colored pixel
in those "dropped" pixels place (and normalizing this "fill in pixel
color" as needed to fit the "general background" of the rest of the
picture--with NOT as great a loss of video quality as you would expect
(or a smaller percentage of "normalized" pixels if greater quality is
really needed)

and, a smaller than screen sized "picture" can be broadcast and
"expanded" by "image size extrapolation" (computer makes a lot of
guesses on how to represent it as a larger picture and "fill the
screen"--and attempts to have those "guesses" maintain a reasonable
quality of picture.

and, I could go on and on, however, this is quickly becoming WAY
beyond the scope of the arena we need to hold this
"argument/discussion" within... and there are papers and books which
can do a much finer job than I...

I must say, Len was quite correct in the appraisal of your mental
aptitude, I would venture to say this with confidence, as damn few
women would have hung with this technical discussion as you have...

.... are you single, just how old are you? leering-smile

.... just kidding, well, mostly--I AM single yanno!
grin

Warmest regards,
John

"Dee Flint" wrote in message
...

"KXHB" wrote in message
ink.net...

"Mike Coslo" wrote


So here we are.


Yup, and no one has persuaded me it can't be done. I've only been
persuaded that we haven't figured out how yet. (Sorta reminds you,
doesn't it, of how those old-tymey hams must have felt when they
were told to take their party to "200 meters and below".) You,
Jim, and Dee bemoaning how hard it will be, and John raising the
tantalizing notion that we may only be a few "eureka!!!"s away from
something workable. Outside my area of competence, but I'll watch
the dialog with interest.

73, de Hans, K0HB

From my understanding of John's comments, he is saying it can be
done now with current technology. He does not however tell us how.
He just chatters on about "compressing it enough" without stating
the degree of compression, etc.

Hey I'm all for the "eureka" when it happens but the problem is that
it is unpredictable. Not only is it unpredictable in time but in
the nature of the breakthrough.

Dee D. Flint, N8UZE