From: FP on
On 24/11/2009 17:44, Robert Billing wrote:
> As the bottle floated ashore we opened it and found the message that FP
> had written:
>
>
>>On 23/11/2009 15:53, Vince Coen wrote:
>>
>>>Hello Frank!
>>>
>>>20 Nov 09 22:08, Frank Peelo wrote to All:
>>>
>>> FP> I've got one. I got given a DVD from my brother in America for my
>>> FP> birthday. It almost sort of played, but was in black & white.
>>
>>That was in response to Tony Houghton's saying thet DVD players and TVs
>>that can't do both NTSC and PAL are quite rare. They are rare. But if
>>you have one it's still a nuisance.
>
>
> I really think I ought to come in here. After a decade and a half in
> broadcasting and a couple of RTS awards I think I'm entitled to say, "It's
> a bit more complicated than that."

> 1) PAL and NTSC are standards for colour encoding. They are commonly
> associated with 625/50 and 525/60 scan standards, but don't have to be.
> The BBC made colour test transmissions in 405/50 NTSC in the late 50s and
> early 60s.

yes, but in my case the colour encoding is the only problem. The DVD
player is generating the colour encoding signal, whether PAL or NTSC.
The mpeg files on the DVD disc aren't going to have a bunch of bits at
the start of each scan line to represent the colour burst, are they?
They're digital pictures, they will have pixels. So, the DVD could as
easily send out a PAL signal -- even if it was 525/60 with PAL --
instead of NTSC. I sort of suspect that many can do that, from what Tony
said.

But mine refuses to play a DVD with NTSC geometry unless I tell it that
it is connected to an NTSC telly. If I do that, it generates NTSC colour
encoding and I get a black & white picture.

> 2) Converting the geometry is quite easy. You just slap on some decent
> filters. A 32-point Bessel will do this for you.

No, it's easier than that! Well, maybe not for people who can afford LCD
tellies, but my old glass bottle has no problem. Just fire out the
525/60 instead of the 525/50 and let the telly display it. CRTs don't
really have pixels, just one "pixel" flying across the screen 15625
times a second. Or 15750, if you're 525/60. And that's only a difference
of 0.8% so the telly can handle that. And it adjusts the frame height to
fill the screen, so that works fine too. No filtering necessary!

So, *if* I tell the player it's connected to an NTSC box, the geometry
and frame rate are not a problem, but the picture is in black and white.
If I tell it to output PAL, it refuses to play the DVD because it
doesn't like the geometry or frame rate. If I convert the DVD so that
the player likes the geometry and frame rate, then, as you say:

> 3) It's the time domain that plays hob with what you want.

So I continue to believe that the easiest thing to do is to play it on
the computer. Or buy a better DVD player, but that's not going to happen.

Frank
From: Robert Billing on
As the bottle floated ashore we opened it and found the message that FP
had written:

> But mine refuses to play a DVD with NTSC geometry unless I tell it that
> it is connected to an NTSC telly. If I do that, it generates NTSC colour
> encoding and I get a black & white picture.

Which is mildly annoying.
>
>> 2) Converting the geometry is quite easy. You just slap on some decent
>> filters. A 32-point Bessel will do this for you.
>
> No, it's easier than that! Well, maybe not for people who can afford LCD
> tellies, but my old glass bottle has no problem. Just fire out the
> 525/60 instead of the 525/50 and let the telly display it. CRTs don't
> really have pixels, just one "pixel" flying across the screen 15625
> times a second. Or 15750, if you're 525/60. And that's only a difference
> of 0.8% so the telly can handle that. And it adjusts the frame height to
> fill the screen, so that works fine too. No filtering necessary!

If you have a multistandard display this isn't a problem. However
broadcast 625/50 is in fact processed at the studio as bing 720x576, hence
the pixels. I spent a lot of my life brewing up digital filters to make
the conversions.

> So, *if* I tell the player it's connected to an NTSC box, the geometry
> and frame rate are not a problem, but the picture is in black and white.
> If I tell it to output PAL, it refuses to play the DVD because it
> doesn't like the geometry or frame rate. If I convert the DVD so that
> the player likes the geometry and frame rate, then, as you say:

Can you get RGB, YUV or YIQ out of the player?

> So I continue to believe that the easiest thing to do is to play it on
> the computer. Or buy a better DVD player, but that's not going to
> happen.

Agreed.

--
I am Robert Billing, Christian, author, inventor, traveller, cook and
animal lover. "It burned me from within. It quickened; I was with book
as a woman is with child."
Quality e-books for portable readers: http://www.alex-library.com