/* from web:
Video Sampling
Digital video is a sampled form of analog video. The most common sampling schemes in use today are:
- Pixel Clock Horiz Horiz Vert
- Rate Total Active
+ Pixel Clock Horiz Horiz Vert
+ Rate Total Active
NTSC square pixel 12.27 MHz 780 640 525
NTSC CCIR-601 13.5 MHz 858 720 525
NTSC 4FSc 14.32 MHz 910 768 525