Comments by "Scott Franco" (@scottfranco1962) on "Compatible Color: The Ultimate Three-For-One Special" video.

  1. This is a good overview. The basic underlying trick of color TV, or why they could stuff 3 colors into a black and white signal, was that still images (or slowly moving images) in TV don't really take the full bandwidth of a TV channel, but rather occupy a series of harmonics, or peaks in the signal spectrum at regular intervals. The color signal is fitted into the spaces between those peaks. What happens if the picture is moving? The color actually degrades quite a bit, which you can see if you hit stop during those times. The color becomes blotchy. They are taking advantage of the fact that you can't perceive color very well in any case in a fast moving image. The TV engineers effectively used signal compression, in analog, before digital TV made that standard. The system was pure genius at that time, but of course we are stuck with the re-recorded artifacts of old video to this day.
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  2. The war over color TV standards got repeated with the advent of HDTV. The FCC had already signed off on an analog, backwards compatible system when a small silicon company called general instrument showed that by using a digital carrier based system with mpeg, the amount of bandwidth needed by the (very wasteful) analog TV system could be reduced significantly, while at the same time dramatically increasing the reception reliability. GI had already done this for digital cable systems, so over the air systems had fallen behind. The FCC did another about face, and the broadcasters suddenly did as well. Cynics said that the true underlying cause was the broadcasters realization that the very same digital technology that could give an HDTV signal in the same 6mhz channel as analog TV could very well be used to compress existing TV into 1mhz or less, and result in broadcasters losing up to 5/6ths of their very valuable spectrum real estate if the FCC (and the public) woke up to this fact. Thus HDTV was born, and the broadcasters used the technology to split up into multiple channels anyway... but under their control. The true result of all of the nonsense is that mpeg-2, and later mpeg-4, took over TV broadcasting by storm, rendering the actual method used to broadcast TV increasingly irrelevant. The broadcasters kept their spectrum allocations, but the number of over the air users decreases daily. And the FCC increasingly puts pressure on broadcasters to give up that real estate to other uses.
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