Re: [doc] DVD Regions and TV Formats

[Martin Gutkowski <webmaster@xxxx>]

Paul Feagan wrote:

> In England we have a TV system called PAL. The main feature of PAL is that
> there are 625 lines of dots on the TV screen. The line scan part of the TV
> lights these dots from the top of the screen to the bottom, left to right,
> about 50 times a second. It actually lights lines 1, 3, 5 etc then 2, 4, 6
> and relies on persistence of (human) vision to make a picture.

Not quite: It displays the same frame twice by illuminatig alternate lines on each scan. On a computer it's called interlacing
and looks awful, however the phosphor on a TV screen is meant to take it and has a "slower" fade time.

> Around the
> world there are different versions of PAL

A PAL dvd is a PAL dvd though - which is good for us!

> In the US they have a system called NTSC. This uses 525 lines. As a result
> US TV is a lower definition to ours. The other problem is that NTSC, played
> on a PAL TV, means that the line scan gets to 525 lines and starts again.

Again not quite: the problem is that NTSC is 60Hz - ie the screen refreshes every 1/60th of a second instead of every 50th.
Most modern TVs can easily cope with a 60Hz scan rate unfortunately NTSC also uses a different colour encoding. Often you'll
see the picture clear enough but it'll be black and white. The 525 lines sometimes puts black bars at the top and bottom and
squashes the picture vertically - like the older games consoles do.

> Luckily most modern UK TVs and videos can handle NTSC signals.

Most TVs can handle 60Hz, and a lot of DVD players will output PAL60 which i PAL at 60Hz. Larger TVs, and particularly WS ones
will display NTSC, but it's far better to rely on either S-Video or RGB as this is independent of TV system (except 50/60Hz
differences. PAL VCRs can sometimes play an NTSC video, but they do it badly - the video dumps 1/6th of the frames to make
50Hz from 60Hz, so panning movements are really jerky.

> There is no technical reason why any UK DVD player can't play any DVD to a
> modern UK TV. Most DVD players are PAL/NTSC compatible.

All are due to Region 2 covering Japan, which is NTSC

> Now the movie studios know that everyone is doing this, they brought out
> something called Region Coding Enhancement (RCE) which confuses some players
> and stops them playing the other region.

This affects the "region 0" players - this is an old mod and not used anymore to my knowledge because of RCE discs.

> So the result of all this is that the Aussie DVD BTTF Trilogy is in PAL
> which is the same as the UK, but still has Region 4 coding.

I was wrong here - it is both R2 and R4 so you DO NOT need a multi-region player. Thanks Paul H for setting me strait. (quite
rightly too).

> For people in the US, I'm not sure if they can play it or not. Has anyone in
> the US got the Aussie DVD?

They are unlikey to be able to play it for the reason you mentioned: Their TVs haven't got a high enough resolution.

Martin