i found the standard at philips site (pages 1-16):
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usually this standard goes with ccir 656 (pages 18-31)
additional info:
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this standard defines digital video coding standards for video broadcast:
it defines 3 video signals: Y, Cb, Cr (derived from the common signals R, G, B) and digital values for common colours
later it defines 2 encodeing parametrs 13.5 and 18MHz for 2 systems 50Hz and 60Hz and sampling format
for instance for 13.5MHz in system 50Hz/625 lines (common system for europe) there should be 864 y signals (720 of the active signals) in a line
sampling format: 4:2:2 means that y sampling appear in every pixel and Cb, Cr sampling appear only at every second pixel
the Y rate is 13.5MHz and Cb, Cr rates are 6.75MHz each, total 27MHz
the input for the video encoder may be 1 multiplexed bus (Y, Cb, Cr) rate 27MHz or 2 buses: for Y rate 13.5MHz and for Cb, Cr rates total 13.5MHz
the timing of the Y, Cb, Cr signals are also coordinate to analogue video signal timing
standard 656 continue and defines also parallel and digital interfaces for this standard