Rob wrote:
John Rumm wrote:
wrote:

We've got a Toshiba widescreen rear-projection TV, and an 'el cheapo'
DVD player. The problem is that when playing DVD's which are in the
4:3 format, the TV keeps switching between 4:3 and widescreen, after
the DVD has been playing for a few minutes. It seems to work OK with
widescreen discs.

So, what do people think, is there a fault with the TV, or the DVD
player?

The TV switches OK with our el cheapo Freeview decoder, putting in
grey 'curtains' when showing 4:3.

Can you turn off the auto format selection on the TV in these
situations? i.e. manually set it to 4:3 rather than let it auto select.


That's what I have to do - for some reason something in the signal
causes the auto-format to kick in.

Auto switching is achieved by three mechanisms. One is via the SCART
lead - there is a wire (pin 8) dedicated to the format - the voltage on
it will dictate the format. In addition, many TVs recognise a signal
inserted onto one of the video lines. Finally, some TVs will attempt to
analyse the picture content and "zoom" as appropriate. Alas many make a
bit of a pigs breakfast of this, and you can get format hopping as you
describe. With broadcasts you sometimes get confused signalling being
sent out which can also make matters worse.

--
Cheers,

John.

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