Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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  #1   Report Post  
DON
 
Posts: n/a
Default Video Stabiliser

Hey Guy's ...I just wanted to know of an easy device or circuit I could
build myself..not to cause a heated discussion.. Thanks



"Franc Zabkar" wrote in message
...
On Sat, 28 Jun 2003 15:17:27 +1000, "DON" put
finger to keyboard and composed:

Has anyone purchased the Video Stabiliser Kit from Oatley Electronics. I
have found its performance to be very poor. The brightness fades in and

out
when connected between two VCR's.

If anyone knows of any modifications to it to make it perform better or

even
knows of a totally better circuit and would email it to me I would be

most
appreciated.

Don


WES Components, Ashfield, have a video stabilizer, code CP2, for $45
to the trade. Retail price is around $90, from others. I have seen it
working VCR-to-VCR.


http://www.cypress.com.tw/product.ph...Video%20Proces
sors&SR=0


-- Franc Zabkar

Please remove one 's' from my address when replying by email.



  #2   Report Post  
Winfield Hill
 
Posts: n/a
Default Video Stabiliser

Jim wrote...

Macrovision *does* comply with NTSC specs. Unfortunately some older
TV's may have AGC systems which can't cope with the MV "over-white".
I haven't seen a set in years which reacted adversely to MV.


My 27" Panasonic often fails on MV tapes. It's a full-feature set
that's not that old. :)

Thanks,
- Win

  #3   Report Post  
Peter Gottlieb
 
Posts: n/a
Default Video Stabiliser

Going over 100% white complies with NTSC specs?


"Winfield Hill" wrote in message
...
Jim wrote...

Macrovision *does* comply with NTSC specs. Unfortunately some older
TV's may have AGC systems which can't cope with the MV "over-white".
I haven't seen a set in years which reacted adversely to MV.


My 27" Panasonic often fails on MV tapes. It's a full-feature set
that's not that old. :)

Thanks,
- Win



  #4   Report Post  
Mark Zenier
 
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Default Video Stabiliser

In article ,
Ray L. Volts wrote:

"DON" wrote in message
...
Hey Guy's ...I just wanted to know of an easy device or circuit I could
build myself..not to cause a heated discussion.. Thanks


I built one many years ago from an R-E article. I'll tell you which issue
number when I find it. I dunno if it'll work on PAL systems, but it's a
good source of info on Macrovision anyway.


But there's some newer versions of Macrovision that dork around with
the color/colour burst reference. Elektor had an article on it
two or three years ago, and it looked nasty.

Mark Zenier Washington State resident

  #5   Report Post  
Andre
 
Posts: n/a
Default Video Stabiliser

"Ray L. Volts" wrote in message ...
"DON" wrote in message
...
Hey Guy's ...I just wanted to know of an easy device or circuit I could
build myself..not to cause a heated discussion.. Thanks


I built one many years ago from an R-E article. I'll tell you which issue
number when I find it. I dunno if it'll work on PAL systems, but it's a
good source of info on Macrovision anyway.


If they patented every possible circuit, did that include using a PIC
to decode the signal ?



-A


  #6   Report Post  
Richard Crowley
 
Posts: n/a
Default Video Stabiliser

"Andre" wrote ...
If they patented every possible circuit, did that include using a PIC
to decode the signal ?


How do you use a PIC to "decode" an analog video signal?


  #7   Report Post  
Franc Zabkar
 
Posts: n/a
Default Video Stabiliser

On Fri, 4 Jul 2003 07:35:06 +1000, "DON" put finger
to keyboard and composed:

Hey Guy's ...I just wanted to know of an easy device or circuit I could
build myself..not to cause a heated discussion.. Thanks


Hey, why single me out. :-(

If you want to build a macrovision killer kit, er I mean video
stabiliser, then consider a kit based on the LM1881 sync stripper IC
which was published by Silicon Chip magazine not too long ago. I
believe Jaycar sells it.

"Franc Zabkar" wrote in message
.. .
On Sat, 28 Jun 2003 15:17:27 +1000, "DON" put
finger to keyboard and composed:

Has anyone purchased the Video Stabiliser Kit from Oatley Electronics. I
have found its performance to be very poor. The brightness fades in and

out
when connected between two VCR's.

If anyone knows of any modifications to it to make it perform better or

even
knows of a totally better circuit and would email it to me I would be

most
appreciated.

Don


WES Components, Ashfield, have a video stabilizer, code CP2, for $45
to the trade. Retail price is around $90, from others. I have seen it
working VCR-to-VCR.


http://www.cypress.com.tw/product.ph...Video%20Proces
sors&SR=0


-- Franc Zabkar

Please remove one 's' from my address when replying by email.




- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
  #8   Report Post  
Richard Crowley
 
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Default Video Stabiliser

"Richard Crowley" wrote ...
How do you use a PIC to "decode" an analog video signal?



"Chris Mann" wrote...
Most PICs have ADCs built in. Sounds interesting.


Maybe if the ran 20-50x faster they could be used for video.
What's the fastest PIC ADC?
High quality video needs ~ 10-15MHz sampling rate


  #10   Report Post  
R. Steve Walz
 
Posts: n/a
Default Video Stabiliser

Chris Mann wrote:

"Richard Crowley" wrote in message
...
"Richard Crowley" wrote ...
How do you use a PIC to "decode" an analog video signal?



"Chris Mann" wrote...
Most PICs have ADCs built in. Sounds interesting.


Maybe if the ran 20-50x faster they could be used for video.
What's the fastest PIC ADC?
High quality video needs ~ 10-15MHz sampling rate



We're talking about stabilizing a video signal which deals mainly with the
sync and possible AGC levels. There's no reason to mess with the video info
so that kind of speed isn't needed. A PIC should be able to easily handle
the sync and detect black level, too, without speed being an issue.

----------
You don't even NEED a damned PIC.
-Steve
--
-Steve Walz ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public


  #11   Report Post  
Leonard Caillouet
 
Posts: n/a
Default Video Stabiliser


"R. Steve Walz" wrote in message
...
Chris Mann wrote:

"Richard Crowley" wrote in message
...
"Richard Crowley" wrote ...
How do you use a PIC to "decode" an analog video signal?


"Chris Mann" wrote...
Most PICs have ADCs built in. Sounds interesting.

Maybe if the ran 20-50x faster they could be used for video.
What's the fastest PIC ADC?
High quality video needs ~ 10-15MHz sampling rate



We're talking about stabilizing a video signal which deals mainly with

the
sync and possible AGC levels. There's no reason to mess with the video

info
so that kind of speed isn't needed. A PIC should be able to easily

handle
the sync and detect black level, too, without speed being an issue.

----------
You don't even NEED a damned PIC.
-Steve
--
-Steve Walz ftp://ftp.armory.com/pub/user/rstevew


Once again, a really USEFUL post by Steve. Why not use your great intellect
to be more helpful to people, Steve?

Leonard Caillouet


  #12   Report Post  
R. Steve Walz
 
Posts: n/a
Default Video Stabiliser

Leonard Caillouet wrote:

"R. Steve Walz" wrote in message
...
Chris Mann wrote:

"Richard Crowley" wrote in message
...
"Richard Crowley" wrote ...
How do you use a PIC to "decode" an analog video signal?


"Chris Mann" wrote...
Most PICs have ADCs built in. Sounds interesting.

Maybe if the ran 20-50x faster they could be used for video.
What's the fastest PIC ADC?
High quality video needs ~ 10-15MHz sampling rate



We're talking about stabilizing a video signal which deals mainly with

the
sync and possible AGC levels. There's no reason to mess with the video

info
so that kind of speed isn't needed. A PIC should be able to easily

handle
the sync and detect black level, too, without speed being an issue.

----------
You don't even NEED a damned PIC.
-Steve
--
-Steve Walz ftp://ftp.armory.com/pub/user/rstevew


Once again, a really USEFUL post by Steve. Why not use your great intellect
to be more helpful to people, Steve?

Leonard Caillouet

------------------------------
Look:
http://www.armory.com/~rstevew/Public/RF_Ccts/

-Steve
--
-Steve Walz ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
  #13   Report Post  
Peter Gottlieb
 
Posts: n/a
Default Video Stabiliser


"Michael A. Terrell" wrote in message
...
Try it, then tell us how well it worked with a low sample rate and a
slow processor.



With a decent S/H it shouldn't be a problem. I haven't looked at recent PIC
devices to even get a good gut feeling whether or not they could do it, but
in theory they have the speed and power.


  #14   Report Post  
Mark Zenier
 
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Default Video Stabiliser

In article ,
Lewin A.R.W. Edwards wrote:
(Andre) wrote in message
.com...

If they patented every possible circuit, did that include using a PIC
to decode the signal ?


I notice that my posting listing all the patent numbers is no longer
on Google's archive. The conspiracy theorist in me says this isn't
coincidence.


It's still there, but it doesn't come up in the thread index that you get
from the group's subject list pages. I found it by doing an advanced
search in sci.electronics.repair (it's not cross-posted, like much of
this thread), limited with postings only from you as author, sort by date.

Then under the returned article list is an article with the thread index
with a higher article count than the one in the group's subject list.
(44 vs. 39 as of this afternoon PDT.) (Let's see how long that still
works. :-( Maybe it's an artifact of how the thread indices are cached.
Probably not.)

Hell, let's test it out.

From: (Lewin A.R.W. Edwards)
Newsgroups: sci.electronics.repair
Subject: Video Stabiliser
Date: 30 Jun 2003 13:18:02 -0700


LAE But it is an infringement of MV-owned patents to build almost any
LAE device you can think of that will remove the copy protection.

It is legal for a technician to experiment on *any* circuit they build.


Well, actually no - the ****ed-up DMCA could getcha if you're trying
to crack a hardware copy-protection scheme unless you show it's for
academic research (which could be difficult). It's the same, legally,
as reverse-engineering smartcards to steal DSS service, or
reverse-engineering a DVD player's firmware so you can work out how to
turn off Macrovision on the analog outs.

But anyhow, that's not what I was talking about. Patent violation is
tort law, not criminal. Macrovision filed - and was granted - a large
number of patents related to cracking their technology. The intention
was to enable enforcement action against people who build and sell
Macrovision scrubbers.

For example, see the following US patents:

6,295,360 "Method and apparatus to defeat composite video signal
protection"
6,285,765 "Method and apparatus for reducing effects of copy
protection of composite video signal"
6,173,109 "Method and apparatus for removing or defeating effects of
copy protection signals from video signal"
6,058,191 "Method and apparatus for modifying the envelope of a RF
carrier signal to remove copy protection signals therefrom"
6,002,830 "Method and apparatus for removing or defeating effects of
copy protection signals from a video signal"
5,953,417 "Method and apparatus for digitally removing or defeating
effects of copy protection signals from a video signal"
5,784,523 "Method and apparatus for defeating effects of color burst
modifications to a video signal"
5,748,733 "Method and apparatus to reduce effects of certain copy
protection purses within a video signal"
5,661,801 "Method and apparatus for stabilizing and brightening
prerecorded TV signals encoded with copy protection"
5,625,691 "Method and apparatus to defeat certain copy protection
pulses within a video signal"

Just search USPTO for "macrovision" and you'll see some of their raft
of patents. About 30% of them are patents specifically covering
*defeating* technology, not the copy protection systems themselves.


....

Mark Zenier
Washington State resident

  #15   Report Post  
Steve Sousa
 
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Default Video Stabiliser

"Michael A. Terrell" wrote in message ...
Try it, then tell us how well it worked with a low sample rate and a
slow processor.



You guys are so complicated... :-)

A pic12508 running on it's internal 4MHz clock + an lm1881 sync
separator does the job just fine.
There's no need to digitize the video information. You just have to
clamp the undesired signals to black level, you do this by counting
lines and syncing(sp?) to the vertical sync, this happens at most at
15625Hz for the pal people, slow enough for a pic. With a discrete
sync separator and running the pic at 10MHz you could skip the lm1881.

Greetings


  #16   Report Post  
Winfield Hill
 
Posts: n/a
Default Video Stabiliser

Lewin A.R.W. Edwards wrote...

I notice that my posting listing all the patent numbers is no longer
on Google's archive. The conspiracy theorist in me says this isn't
coincidence.


You could repost it.

Thanks,
- Win

  #17   Report Post  
Clifford Heath
 
Posts: n/a
Default Video Stabiliser

Franc Zabkar wrote:
If you want to build a macrovision killer kit, er I mean video

stabiliser, then consider a kit based on the LM1881 sync stripper IC
which was published by Silicon Chip magazine not too long ago. I
believe Jaycar sells it.


Or for the same price (~$AU60) you could buy Jaycar's Dr Video unit,
which works fine for my 1984 Toshiba TV. No assembly needed, and
comes with a "video enhancer" button :-). The RF modulator option
can work too, but since the one in my Mitsubishi VCR didn't work to
play DVDs on the Toshiba, I figured the possible hassle of trying
it wasn't worth the saving.

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