NTSC Video [OT][EE]
> Hi all,
> Could someone point me to a good online reference on NTSC video?
Try any of the Elantec video IC data sheets, start with the EL4583 sync
separator. I think you'll find that it gives a good explanation of the
basic waveform of the video signal with diagrams relating it to the
output of the chip. http://www.elantec.com/pages/products_video.html
> Also, could someone please tell me if there is a way to determine which
> field is odd and which is even? From the (poorly written) reference I am
> currently looking at, it looks as if the vertical sync is the same for
> both the odd and even fields so that when you assemble the frame, you
> don't know which field belongs to which frame (and, therefore, you odn't
> know which is odd and which is even).
If you use a sync separator chip as above you have a digital output
indicating which field is which. From the raw video waveform the
difference between fields can be worked out from the relationship
between the horizontal sync. pulses and the vertical sync. pulse during
the vertical blanking interval. See the timing diagrams in the above
For a detailed description of a simple video digitizing circuit built
with discrete logic visit http://www.ucl.ac.uk/~ucapwas/video.html.
Not sure if there are low cost single chips for timing/digitisation
Put your next PIC project on TV!
See also: www.piclist.com/techref/displays.htm?key=ntsc
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