If the signal is in analog, then there is no 'pixels per line', but in real=
ity =

we can find two cases, looking at the original digital signal:  a 270Mb/s =

720x483(NTSC) or 720x58x(PAL) signal that is to be displayed in a 16:9 scre=
en =

instead of the regular 4:3 screen; or the second case where the signal come=
s at =

360Mb/s 16:9 native, and has more information than the 4:3 signal.  Don't =

remember how many pixels per line 360M/s has (I think there are 960pixel/li=
ne), =

but rest of parameters are the same as the 270Mb/s signal.

In analog, if the signal comes from a 360Mb/s signal, the sampling should b=
e =

18Mhz, instead of the 13.5Mhz that 270M/s uses.  In neither case you will h=
ave =

square pixels!

Now FYI, the analog singal carries some info on one line that tells the rec=
eiver =

if it is a 4:3 or a 16:9 signal; so the "conversion" from one aspect ratio =
to =

the other is done by squeezing, croping o streching, depending on where to =
where =

the signal goes.  If you have and old TV and feed the 16:9 signal, you will=
 see =

it squeezed (pretty high people, sort of old cinema conversion to tv from 2=
:1 to =

4:3 aspect ratio), but a new one will crop it or sandwich it, depending on =
a =

menu setting or device capability.  The same happens when you feed a 4:3 si=
gnal =

to a 16:9 display, it autodetects, but depending on your menu settings it w=
ill =

display it centered, strectched, or croped top/bottom.



Ivan
----------------

Charles Craft escribi=F3:
> Should probably do this over on one of the TV forums but coming at it fro=
m the bottom up here.  :-)
> =

> I've got a satellite TV receiver that can be configured for 4:3 and 16:9 =
aspect ratios.
> Video outputs are RF (Ch 3 or 4), composite video? (RCA jack) and S-video.
> =

> When you change the aspect ratio of an analog TV signal does it keep the =
same number
> of scan lines and cram more "pixels" on each line? Would all of the analo=
g connectors
> above support the different ratios or would some only support 4:3?
> =

> thanks
> =

> =


-- =

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