[sci.electronics] converting PAL to NTSC and back

simon@ms.uky.edu (Simon Gales) (07/25/88)

I will be working with some european video equipment soon, and will
be needing a new color camera or camcorder to use with it.  The problem
is that in europe the video signals are a different standard from here,
I believe it is PAL standard over there (more scan lines or something) and
here we use NTSC.  
  
What I want is a NTSC to PAL converter to be able to input NTSC into my
european frame grabber.   I would also like to go the other way (PAL to
NTSC) in order to record the output on an american (NTSC) vcr.

Has anyone heard of such a creature?  I would imagine going from PAL to
NTSC would be easy, but the other direction could be trickier (not enough
scan lines).  I would appreciate ANY help or references on how to make one
of these, or even tips on companies who already produce one.
									Thanks In Advance...
												   Simon Gales.


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brown@nicmad.UUCP (Mr. Video) (07/25/88)

In article <10034@e.ms.uky.edu> simon@ms.uky.edu (Simon Gales) writes:
<What I want is a NTSC to PAL converter to be able to input NTSC into my
<european frame grabber.   I would also like to go the other way (PAL to
<NTSC) in order to record the output on an american (NTSC) vcr.

The average cost for a good digital standards converter is $20,000.  I under-
stand that cheaper models are now becomming available.  But I don't know what
those are like (for quality).

In other words, welcome to the world of non-standard video and big bucks!
-- 
	       harvard-\	att!terminus--\
Mr. Video         ucbvax!uwvax.................!nicmad!brown
	       rutgers-/        att-/ decvax--/

dya@unccvax.UUCP (York David Anthony) (07/27/88)

In article <2922@nicmad.UUCP>, brown@nicmad.UUCP (Mr. Video) writes:
> In article <10034@e.ms.uky.edu> simon@ms.uky.edu (Simon Gales) writes:
> <What I want is a NTSC to PAL converter to be able to input NTSC into my
> <european frame grabber.   I would also like to go the other way (PAL to
> <NTSC) in order to record the output on an american (NTSC) vcr.

> The average cost for a good digital standards converter is $20,000.  I under-

> In other words, welcome to the world of non-standard video and big bucks!

	Assuming that the frame grabber is connected to your handy-
dandy Multibus, Unibus, or other trademarked-bus, with a general
purpose computer at the other end, it would seem trivial to me to
write a half-decent standards conversion program to operate on a
single frame. 

	Doing this fully-decent, though, would require a decent
computer, at least a MC68020 running single-user with cache enabled
doing a 2d FFT of an NTSC image (matrixed at 512 pixels squared)
takes a fairly long time. This, with the coprocessor too. (We just
got our hardware yesterday.  However, on an Omni-Byte OB68K1A with
MC68010 cpu and hardware coding, it takes tens of minutes. This,
though, without using lookup tables for sin(x), etc.)

	Virtually any manipulation looks like crap in the time 
domain (edge artifacts, etc.).  Real time standards conversion uses
the temporal aspect to hide the non-optimal conversion algorithms
in use.

	Image-Pro, from those guys up in Potomac, Md. running on 
a 286/287 pc with their own accelerator, ain't half bad for standards
conversion, but 'tis 'spensive. You could call Media Cybernetics
and ask them.

	Mr. Video is right.  Probably the best solution (for the wallet)
is either write your own frame conversion routines (and move mag tape
from machine to machine) or buy multirate VCR's.

	Converting NTSC to PAL within the same scanning system is 
trivial. Converting system B to system M is the hard part !!!!

York David Anthony
DataSpan, Inc.

perl@step.UUCP (Robert Perlberg) (08/03/88)

I don't know about NTSC->PAL, but there is a machine that does
PAL->NTSC.  It's made by a company called Instant Replay and the
machine is called the Image Translator.  It looks like a regular VHS
VCR, but it plays tapes of almost every world VHS format and converts
the signal to NTSC on the way out.  I don't know what it's recording
capabilities are.

I don't have a copy of Video magazine with me, but they have an ad for
it almost every month.

Robert Perlberg
Dean Witter Reynolds Inc., New York
phri!{dasys1 | philabs | manhat}!step!perl
	-- "I am not a language ... I am a free man!"

brown@nicmad.UUCP (Mr. Video) (08/07/88)

In article <1310@number1.step.UUCP> perl@step.UUCP (Robert Perlberg) writes:
<I don't know about NTSC->PAL, but there is a machine that does
<PAL->NTSC.  It's made by a company called Instant Replay and the
<machine is called the Image Translator.  It looks like a regular VHS
<VCR, but it plays tapes of almost every world VHS format and converts
<the signal to NTSC on the way out.  I don't know what it's recording
<capabilities are.

Well, not exactly.  It doesn't convert everything to NTSC.  The color is
converted, but the frame/timing rates are still PAL, ie, 625 line 50 Hz.
Most American TVs will lock onto that just fine.

You will NOT be able to record the output of one of these machines onto
a NTSC VCR.
-- 
	       harvard-\	att!terminus--\
Mr. Video         ucbvax!uwvax.................!nicmad!brown
	       rutgers-/        att-/ decvax--/