Does posting in stereo (twice) help the fidelity?

Charles Craft wrote:

> Should probably do this over on one of the TV forums but coming at it from 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

You CANNOT change the aspect of the TV "SIGNAL". It is FIXED by the television standard
in use. 525 lines/ 60 fields per second (640x480) or 625 lines/ 50fps (800x600).

> of scan lines and cram more "pixels" on each line?

Depends.
An ANALOG signal has a nearly infinite number of pixels per line.
It is up to the display as to how many samples per scan line it takes, and then
what kind of scaling is done to fit the samples onto the 'native' screen resolution.
The quality of this scaler is what gives the wide disparity in prices of similarly sized
televisions.

> Would all of the analog connectors
> above support the different ratios or would some only support 4:3?

All the above listed outputs will only be 4:3 timing (NTSC or PAL).
They are fundamentally 'television' ports.

The satellite receiver may be able to scale the received DVB signal to
fit 16:9 DVB content into a 4:3 format.
It does this by reducing the number of horizontal display lines with content.
e.g. only filling 272 of the 480 visible scan lines (aka letterboxed).

But the output TIMING will still be 4:3 for the outputs you have listed.
Typically, only component (RGB, YRpBp), or HDMI/DVI/IEEE1394/VGA video will have true
16:9 aspect ratio timing).

The reason your satellite receiver has this aspect setting option is that it can squeeze
the 16:9 content into the 4:3 ratio and then have the DISPLAY unsqueeze it (with a cost
to image fidelity)
e.g. give full vertical resolution by providing an anamorphic signal (in 4:3) that
the display will then stretch to fill it's native pixel map.
You won't get an HDTV 16:9 signal out of the ports you have listed.

Robert

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