I know what macrovision is, but what is CP?

[Sabro]

While backing up two of my xmas presents (Family of Cops, and Family of Cops II starring Charles Bronson) (Walmart specials I'd believe) I notiiced
on the back of the dvd cover it has a triangle and inside it it has a CP.

Under the triangle it says Copy Protection. Althought EasyVcd did the job
great as usual, I was just wondering what CP was and what it attempts to do, since I have been unable to find any info on it or who it was developed by.

Please do not confuse this wth the generic term 'copy protection', this is
suppostly some kind of routine to prevent the copies, or there of, like Macrovision and some of the others.

Thanks,

Sabro

[kpkilburn]

DVDs have three forms of copy protection -- one digital and two analogue:

1. CSS -- Content Scrambling System. Basically encryption. It's what you defeat when you run a "ripper".

2. Macrovision AGC -- noise injected into the vertical blanking interval of the video signal so that automatic gain circuitry in VHS recorders is confused. Characterized by flashing light/dark and sometimes tearing of the video. This is the same as has been used on VHS tapes for years. Works on approx. 85% of consumer VCRs.

3. Macrovision Colorstripe -- a newer protection scheme where the phase of the 3.58 MHz colorburst signal is rapidly changed thus confusing the chroma (color) circuitry in VCRs. Works on approx. 95% of consumer VCRs.

Both #2 an #3 together are called the "Macrovision 7.0" process.

#2 and #3 are not actually on the disc itself since it's digital. The bits are set to on or off to tell the players to activate them and pass them through the analogue outputs.

There are actually other techniques that work at various levels (e.g., -- bits that disallow copying at the manufacturing level -- controls the number of "masters" that can be generated). These are outlined on pages 190-204 of "DVD Demystified" (2nd Edition) by Jim Taylor.

When the DVD standard was first developed, the "Copy Protection Technical Working Group" came up with the anti-copying standards that are now implemented.

It's possible that the symbol you see on the DVD cover signifies that your particular DVD uses the copy protection standards set forth by the CPTWG. Just a guess though.