Since the horizontal is not discrete and is contained in an analog signal, you
can have just about as many horizontal pixels as you want. 640x480 will give you
square pixels, but 768 will match the signal a little cleaner.

Also, 768x576 at 25 frames per second is really two 768x288 fields per frame, and
thus 768x288 x 50 fields per second. One field has all the odd scan-lines, the
next field has all the even scan-lines. Then you also get into the problem of
field-major (?) or field-minor, where you need to figure out which to send first,
the odd field or the even field. Also, I'm not sure, but I seem to recal that VHS
just records one field of two, but don't hold me to that without checking.


Bob Hughes wrote:

> There's square and non-square pixels apparently.  PAL has a 768 X 576 or 768 X
> 288 frame size according to:
> http://reality.sgi.com/cpirazzi_esd/lg/big/howbig.html
>
> Bob
>
> "Cliff Bowman" <c.b### [at] cwcomnet> wrote in message
> news:388dbe7a.66011648@news.povray.org...
> | On Sat, 20 Nov 1999 22:31:21 -0800, "Jon A. Cruz"
> | <jon### [at] geocitiescom> wrote:
> |
> | >TonyB wrote:
> | >
> | >> So NTSC is 720x480ish. What is PAL?
> | >
> | >720x560 25 fps 9843.75k
> | >
> | >NTSC is 720x480ish 30 fps
> | >
> | I don't suppose you could quote the spec for PAL VHS could you? I know
> | it's less, but as I hope to put some stuff on VHS one day I don't want
> | to overburden my poor PC with too much work...
> |
> |
> | Cheers,
> |
> | Cliff Bowman
> | Why not pay my 3D Dr Who site a visit at http://www.who3d.cwc.net/

--
"My new computer's got the clocks, it rocks
But it was obsolete before I opened the box" - W.A.Y.

Post a reply to this message