|
Macrovision Analog Copy protection (ACP)
This is analog protection system (APS) and it is entirely done by player. The macrovision chip adjust the composite and s-video signal with special modulation that confuses the synchronization and automatic-recording-level of VCR. Newer DVD recorders also detects this signal and will not allow copying.
The vob file contain just a trigger bits that tell player to use (or not) the macrovision AGC on the output signal. These bits occur about every 0.5 sec and you can directly control which part can be copied and which not.
You cannot use the macrovision protection (to turn the bits on) unless you pay licence fee to macrovision + royalties per each copy of disc you distribute.
http://www.macrovision.com
Content Scrambling System (CSS)
A content of VOB file is scrambled and can be unscrambled by player only by using one of the master key that is stored on every CSS encrypted disc. You can't just generate the keys by yourself, you as a content provider, have to apply for a CSS License Certificate from http://www.dvdcca.org/
The request for CSS encryption is then set in the DDP headers (protocol needed to generate a glass master for replication) and mastering company can do the encryption with your encryption licence data.
There is a $15,000 annual licensing fee but no per disc royalties.
One thing very few people realize when requesting CSS feature:
No DVD recorders (even mastering units) can physically write encryption keys to DVD. These keys can be only pressed with glass master by replication house. Therefore encrypting vob files on any DVD recordable media will create 100% unplayable discs. Shortly - you can't (physically) use CSS unless you:
| • |
1) obtain a CSS certificate and a key from DVD Copy Control Association |
| • |
2) And create Glass master by one of these methods: |
| • |
a) use mastering DVD recorder or DLP that can write DDP headers where you turn the flags requesting mastering company to do encryption for you |
| • |
b) encrypt in house and use DLT tape to write DDP and encryption keys |
Generation Management System (CGMS)
The DVD Video copy management mechanism that defines the number of copies permitted of the DVD material. This can be set to none, one, or any number of copies. This is mostly domain of PVR and DVD recorders. CGMS consisting of two bits in the MPEG-2 compressed video stream that indicate the permission. There is no organization policing the CGMS requirement so its implementation in players is questionable.
Region Coding (RCE)
A voluntary flag set in the DVD IFO file that prohibits playing the DVD in certain regions. It is important to realize that this flag is NOT required to be set. You set the region coding exception only if you have a reason why a certain DVD should not be played in certain region. For example big movie studios set RCE to stop creating a gray market because the DVD is released in all regions separately.
If you on the other hand plan to release a DVD in only one region for example in North America, then setting RCE to disable other regions is in fact counter productive. You limit your viewers from other regions to buy your DVD but you have no other intentions to release your DVD in these regions. A best way is not to divide planet to can and cannot and leave the region coding set to 0 = all regions.
Why to use protection?
Copying DVD with or without protection is equally illegal and these days equally easy. The CSS will stop only the people that had never been connected to Internet or had never heard about google. The Analog protection will stop only the people who try to copy the DVD old way, such as to VHS tape - how likely will this happen?
Both CSS and the Analog Copy protection are not free and must be licensed per each project. Therefore it is important to specify what you expect from the protection and research if the protection will deliver that expectation.
What the little cowboy say:
Protection What? Of course for our ultra-low budget DVD any protection (free or licensed) would be like shooting ourselves into the foot. What we would try to protect here? The re-dubbed 1930 serial Trail of the Royal mounted? Or the "Think about it with professor Dave" ? Let's not kid ourselves, it will take a major polar shift or collision of few planets with Earth before we see Chinese video stores packed with illegal copies of our little Cowboy Who? Season 1. And if somebody wants to copy the whole DVD to their cellular phone or PVR mounted on fridge doors, we will even help him with a good advice!
In fact the truth is that any small studio in this cruel world overshadowed by big corporations is actually very lucky if any viewer at all can see their creation!
Do not illegaly copy any DVD! But if you own the copy of Cowboy Who? and you want to transfer it to any of other devices for your viewing enjoyment, we have no problem with it!
Top
Previous
Next
| 
