30-09-2021, 09:52 AM
(29-09-2021, 05:45 PM)ppppenguin Wrote: 720 line systems, always progressive scan, have a total of 750 lines, 30 of which are vertical blanking.
1080 line systems, inerlaced or progressive scan, have a total of 1125 lines, 45 of which are vertical blanking.
The horizontal blanking interval varies with standard to give the same 74.25MHz or 148.5MHz luminance sampling rate.
The Cb and Cr colour difference sampling rates are each half the luminance rate.
Hi Jeffrey
The vertical blanking lines referred to above I would assume are to accommodate CRT TV's.
In a digital system it would appear to be wasteful to transmit them. So are they just inserted at the receiving end or they actually transmitted.
I have to agree this is a interesting thread. I have learned a lot.
Frank
