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Analog Copy Protection
The Analog Protection System (APS), also known as Analog Copy Protection (ACP), Copyguard or Macrovision, is a VHS and DVD copy protection system originally developed by the Macrovision Corporation. Video tapes copied from DVDs encoded with APS become garbled and unwatchable. The process works by adding pulses to analog video signals to negatively impact the AGC circuit of a recording device. In digital devices, changes to the analog video signal are created by a chip that converts the digital video to analog within the device. In DVD players, trigger bits are created during DVD authoring to inform the APS that it should be applied to DVD players' analog outputs or analog video outputs on a PC while playing back a protected DVD-Video disc. In set top boxes trigger bits are incorporated into Conditional Access Entitlement Control Messages (ECM) in the stream delivered to the STB. In VHS, alterations to the analog video signal are added in a Macrovision-provided "processo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copy Protection
Copy protection, also known as content protection, copy prevention and copy restriction, is any measure to enforce copyright by preventing the reproduction of software, films, music, and other media. Copy protection is most commonly found on videotapes, DVDs, Blu-ray discs, HD-DVDs, computer software discs, video game discs and cartridges, audio CDs and some VCDs. It also may be incorporated into digitally distributed versions of media and software. Some methods of copy protection have also led to criticism because it caused inconvenience for paying consumers or secretly installed additional or unwanted software to detect copying activities on the consumer's computer. Making copy protection effective while protecting consumer rights remains a problem with media publication. Terminology Media corporations have always used the term copy protection, but critics argue that the term tends to sway the public into identifying with the publishers, who favor restriction technolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CGMS-A
Copy Generation Management System – Analog (CGMS-A) is a copy protection mechanism for analog television signals. It consists of a waveform inserted into the non-picture vertical blanking interval (VBI) of an analogue video signal. If a compatible recording device (for example, a DVD recorder) detects this waveform, it may block or restrict recording of the video content. It is not the same as the broadcast flag, which is designed for use in digital television signals, although the concept is the same. There is a digital form of CGMS specified as CGMS-D which is required by the DTCP ("5C") protection standard. History CGMS-A has been in existence since 1995, and has been standardized by various organizations including the IEC and EIA/ CEA. It is used in devices such as PVRs/DVRs, DVD players and recorders, D-VHS, and Blu-ray recorders, as well certain television broadcasts. More recent TiVo firmware releases comply with CGMS-A signals. Applications Implementation of C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |