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babbsy_uk
09-12-2001, 01:07
hi can someone please explain to me what macro vision is on films.if i dvd or video is protected by macro vision does that mean that a macro free dvd player can copy these 100%,thanks for you help.
Fatboydim
09-12-2001, 01:36
Macrovision is a type of copy protection... usually to stop people from being able to make video tape copies of DVDs. It can be turned off via software or if you buy a chipped player however.

I'm sure some techies will give you a more thorough explanasion, but you could try typing in MACROVISION into a search engine if you want to know more.
Dave B
09-12-2001, 20:46
What I would like to know is, how does the DVD player or whatever know it is being copied and not watched for macrovision to appear.

Dave
cykedout
10-12-2001, 05:12
From the MacroVision website:
How Does DVD Copy Protection Work?

Rights owners seeking to copy protect their programs would instruct their authoring facility to set certain digital-analog copy protection trigger bits to "on." When the disc is played back in a consumer's home, these trigger bits activate a Macrovision-enabled digital-analog converter chip inside the player. The chip then applies copy protection to the analog output of the DVD player. This allows for transparent viewing of the original program, but causes copies made on most VCRs to be substantially degraded.


Found this link, Fil's FAQ-Link-In Corner: MacroVision FAQ (http://www.repairfaq.org/filipg/LINK/F_MacroVision.html) that might give a better explanation.


Hope this helps.
lynx
10-12-2001, 08:10
Originally posted by Dave B
What I would like to know is, how does the DVD player or whatever know it is being copied and not watched for macrovision to appear.

Dave
Under certain circumstances it is possible for macrovision to interfere with normal veiwing of the movie eg when an protected signal is routed through a vcr and passed on to a tv.I have seen this occurr a few times recently with ITV Digital movies.
LV426
10-12-2001, 08:17
"How does it know if it's being copied or not?"

It doesn't. But, TV's don't have an automatic gain control on the video signal input, whereas VCRs do.

Macrovision adds a signal of hugely varying brightness to that part of the video signal that is between the end of one frame and the start of the next.

On a TV without AGC, this has no effect and is therefore invisible.

On a VCR with AGC, the VCR automatically turns its video gain up and down to compensate for this hugely varying signal. This causes the visible part of the picture to fluctuate hugely in brightness.

On tapes with macrovision, the macrovision signal is recorded right onto the tape.

On DVDs it isn't. It is added by the player in response to a trigger code added to the disc. Hence, it is easy to defeat by firmware hackers.

NOTE: Even if you have a DVD player with macrovision disabled, you will NOT normally be able to tape an NTSC DVD (eg Region 1). This is nothing to do with macrovision. It is to do with the different frame and line frequencies of NTSC over PAL.
Andy_C
10-12-2001, 13:45
Originally posted by LV426

NOTE: Even if you have a DVD player with macrovision disabled, you will NOT normally be able to tape an NTSC DVD (eg Region 1). This is nothing to do with macrovision. It is to do with the different frame and line frequencies of NTSC over PAL.


...although some DVD players can output a modified PAL signal instead of true NTSC. I was able to copy NTSC DVDs onto PAL video tape with my old Samsung 709 player.
kcxdev
10-12-2001, 14:22
I think the sammy can output a pure PAL50 signal from NTSC whereas most others can only do PAL60 which can still be incompatible with most vcr's
Ron Hill
10-12-2001, 16:01
To copy NTSC reliably to VHS you need to have the DVD player output pure NTSC and then have a true multistandard VCR capable of RECORDING NTSC.

Many people make the mistake of seeing the NTSC playback feature on most modern UK VCR's and assume that it can be used to record NTSC. It won't work. The NTSC playback works by outputting PAL60 from an NTSC tape. AFAIK, no VCR can record PAL60.

Another thing to bear in mind is the running time of the tape. Due to the way that NTSC is laid down on tape, you get way less than 3 hours in NTSC mode on a E240. Enemy At The Gates R1 is about the longest you'll fit on an E240 (from my calculations. :D )
ivj
10-12-2001, 17:31
A friend has a portable TV with only one scart socket and wanted to daisychain his DVD player through the VCR but the macrovision ruins the signal even though he is not trying to tape it.

Ian
cykedout
10-12-2001, 20:14
Originally posted by ivj
A friend has a portable TV with only one scart socket and wanted to daisychain his DVD player through the VCR but the macrovision ruins the signal even though he is not trying to tape it.

Ian

Best thing to do in this case is buy a 3 SCART to 1 SCART switchable unit, which you can plug in your various DVDs, VCRs, satellite systems, etc., because your TV has only one SCART socket. You then need only push the appropriate button, in order to switch to the device you want to watch from. I bought one for my brother rcently from Argos for ~£10.