BOC-L Digest / Still in the Shadows

[deadearnest]

ahhhhhh............now I become a little clearer - what a weird state of
affairs - and as u say (or whoever) noone's gonna budge just yet - what a
state!!
Andy G.
----- Original Message -----
From: Paul Mather <paul at GROMIT.DLIB.VT.EDU>
To: <BOC-L at LISTSERV.ISPNETINC.NET>
Sent: Tuesday, June 01, 2004 2:51 PM
Subject: Re: BOC-L Digest / Still in the Shadows


> On Tue, Jun 01, 2004 at 11:27:31AM +0200, Henderson Keith wrote:
>
> => As Paul alluded to...I believe the problem stems fundamentally from
> => the power difference between the US and Europe.  Not so much the
voltage,
> => but rather the frequency.  Again, I'm speaking as a half-wit layperson,
> => but I've understood it to be the case that the scan rate of a PAL TV
> => matches in some way the 50 Hz frequency of the AC power.*  And likewise
> => 60 Hz for NTSC TVs.  And I think maybe even the total number of pixel
> => lines is different between PAL and NTSC TVs.
>
> Yes, the number of scan lines differs too between NTSC and PAL: 525
> lines for NTSC and 625 for PAL.  (This means you get greater spatial
> resolution with PAL, but greater temporal resolution with NTSC due to
> its higher field rate.  Given that film is shot at 24 fps, I'd take
> the increased spatial resolution of PAL, personally...)  But, not only
> that, the way the picture is encoded is different between the two
> systems (leading some to say NTSC = "Never Twice the Same Colour" and
> PAL = "Perfection At Last!":).  And, amongst other things, PAL
> allocates more signal bandwidth to luminance than chrominance, which,
> given the human eye is more sensitive to luminance than chrominance
> differences, can yield perceptually better picture quality with PAL.
>
> This different encoding of the analogue TV signal is a big reason why
> you can't take analogue programme material on a common carrier like a
> VHS tape and play it on the "other" format VCR.  Even though the tape
> is physically the same, the way the picture is encoded is different
> (and gibberish).  The same goes for DVDs.  If the DVD is modulating
> the output analogue picture for a PAL TV, this will be "gibberish" to
> the demodulation circuitry of a NTSC TV (and vice versa).  The
> analogue output of the DVD player has to be speaking a compatible
> "language" that the viewing TV understands.  (Some DVD players are
> smart enough to be "multi-lingual" in this respect.)
>
> => *does this give a sharper picture, or eliminate 'resonance' patterns,
> => if the frequency matches?  I would *guess* this must be the case...
>
> Not that I'm an expert, but I believe it does eliminate resonance
> patterns (rolling hum bars) and gets rid of flicker problems with TV
> cameras in the studio.
>
> => One question I have though...why don't they have *all* the features of
> => these chips activated for every model?  My guess is that it would be
> => harder for them to sell more expensive models, if the cheaper ones had
> => all the same features.  Which means the companies are basically making
> => their products "inferior" intentionally, so that you will pay more for
> => something that isn't really any more advanced, but just has been
'turned'
> => on.  OK, I'm a professional cynic when it comes to mega-corporations,
> => but what other answer is there?
>
> The reason the cheaper models have all the functionality built in (but
> selectively enabled) is because it's cheaper for, say, a Far-East DVD
> player manufacturer to design and build a single unit they can
> mass-produce out the wazoo and sell in all the world markets (Europe,
> North America, Asia, etc.) than to have several specialised units that
> can only be sold in a particular geographic area.  It's a matter of
> economies of scale.
>
> I believe there are several reasons they don't enable all the
> features.  One reason is legal compliance.  For example, it may be
> legal to disable macrovision in some countries but not others, so
> obviously they'd have to enable macrovision in those countries that
> had it as a legal requirement.  Big corporations may also be more
> afraid of being sued if they make it easier for the end-user to defeat
> said legal requirements, e.g., changing the region code, etc., so they
> may "lock down" that kind of feature in hardware rather than making it
> programmable (mutable) via software.
>
> The other main reason would be to cut down on pilot error.  If it were
> easy to, say, switch to PAL-encoded output, then there'd be lots more
> people messing up their units and losing picture on their NTSC TVs by
> playing around with the settings.  I believe that's why a lot of the
> features are accessible only via these hidden "engineer" codes.
> They're ostensibly "for experts only."
>
> Cheers,
>
> Paul.
>
> e-mail: paul at gromit.dlib.vt.edu
>
> "Without music to decorate it, time is just a bunch of boring production
>  deadlines or dates by which bills must be paid."
>         --- Frank Vincent Zappa