Originally Posted by Alimentall
Just because Extron pushes the definition of transcode beyond its normal boundaries for marketing purposes doesn't mean it's the best definition. Note that it's #4 on this list of definitions. Upconvert is still the most accepted term. Transcode is the marketing oriented term.
Composite, S-video and component video are basically the *same* format with different delivery
options. It's all NTSC with varying levels of filtration.
Again you just can't admit that you are WRONG, WRONG, WRONG!!!
You fail to discern the contradiction in your own statement. You state above that the signal
types you enumerate above are all basically the "same" - but you want to use a term like
"up convert". What's "up" about converting signals that are the "same"?
Let me explain the terms that you throw around with abandon without understanding the
meaning. The most basic analog signal is RGBHV. There are five signal lines which carry
the Red, Green, Blue intensities plus the Horizontal and Vertical scanning signals. One can
multiplex the HV scanning signals on the color signal if desired [ usually the Green, if memory
serves], and you have RGB.
Component is just another form of RGB in which the signals are linear combinations of RGB.
The signals in component are Y, Pr, Pb where:
Y = R + G + B
Pr = R - Y
Pb = B - Y
By adding and subtracting the signals Y, Pr, Pb; one can get a different linear combination of
signals that is equal to the original RGB:
R = Pr + Y
B = Pb + Y
G = Y - R - B
There's no "up" or "down" in this conversion - it's simply another linear combination.
[ It basically a question of how many "soda straws" you want to funnel your data through -
the more bandwidth, the merrier].
In S-Video, the luminance Y is on one signal lead, and the color information is multiplexed
onto another signal lead. That's why S-Video is frequently labelled Y/C [Luminance / Color ]
In composite, all the luminance and color information is composited into a single signal.
There's nothing "up/down" in this process which is why up convert is not the preference.
Also - "transcoder" is NOT a marketing term. Scientists and engineers use the term "transcoder"
ALL the time - it's not marketing hype.
I gave you examples of products from 3 manufacturers - so that you would see that the
terminology is not unique to Extron. If you "Google" the term "transcoder" - you will find many
more!!! [ You should get into the habit of using Google - you'd save yourself a lot of embarassment.]
John, you should take Dizzman's advice and go read some books on elementary electronics
and you can try to "correct" people when you are educated in the field.