Building a Standards Converter

[ppppenguin]

I'm usually happy with taking the central 4:3 from a 16:9 picture. Sometimes you end up missing things near the edges. There are various shoot/protect safe area guidelines that should minimise this but not all directors and camera operators are scrupulous about observing them. Anyone remember the horrors of "pan and scan" when showing widescreen films on 4:3 TV systems?

It's unfortunate that we can end up with 2 lots of aspect ratio conversion. One at the sending end where the broadcaster is transmitting 4:3 material in a 16:9 system. The purist approach here is pillarbox, otherwise you can lose an unacceptable amount of information at the top and bottom. Then again at the receiver. At a 4:3 receiver a pillarboxed picture can be restored perfectly. A top/bottom crop then loses its left and right edges so the result is equivalent to zooming in to the central part of the picture.

Pillarboxed transmission tends not to be used - it may be technically correct but it's pretty hideous to the average viewer when seen on a 16:9 display.

In other words the whole aspect ratio business is a mess. There isn't a perfect solution and I doubt there ever will be. You have to put up with what the broadcasters are sending and set the receiver to your personal preferences.