Macrovision

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Macrovision is a company that creates electronic copy prevention schemes, established in 1983. The name is also sometimes used to refer to certain video copy prevention schemes developed by that company.

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[edit] History

Macrovision Corporation was established in 1983. The 1984 film "The Cotton Club" was the first videocassette to be encoded with the Macrovision technology when it was released in 1985. By the end of the 1980s, most major Hollywood studios were utilizing the Macrovision technology. The technology was extended to DVD players when they were first launched in 1997.

[edit] Macrovision for video

A VHS videotape or DVD (no laserdisc or video CD players implement it) or digital cable/satellite boxes receiving a data stream encoded with Macrovision will cause a VCR set to record it to fail (excluding very old models, modified VCRs, or those approved for "professional usage"). This is usually visible as a scrambled picture as if the tracking were incorrect, or the picture will fade between overly light and dark. A 6-head or 8-head VCR (most are 4-head) can minimize this fluctuation, so it is not as noticeable. A DVD recorder will simply display a message saying the source is "copy-protected", and will pause the recording.

This is achieved through a signal implanted within the offscreen range (vertical blanking interval) of the video signal—either physically recorded directly on the tape (as with VHS) or created on playback by a chip in the player (as with DVDs) or the digital cable/satellite box (as with all HDTV programs being down-converted to standard definition).

NTSC and other video formats store the video signal as “lines.” A portion of these lines are used for constructing the visible image by transposing them on the screen, but there are approximately 20 to 40 lines outside the visible range that are used for different things in different countries, like closed captioning.

Macrovision inserts pulses into this non-displayed area. These signals cause the automatic gain control on the recording VCR to compensate for the varying strength. This makes the recorded picture wildly change brightness, rendering it unwatchable. On most televisions, the viewer on the screen sees no effect in ordinary playback of the modified video because the signal is outside the visible area, but some TVs do not properly blank the vertical retrace and leave dotted white lines near the top of the picture. Some newer TVs also mistake the Macrovision pulses for synchronization pulses.

Another modification also used in Macrovision is the addition of colorstripes—rapidly modulated colorburst signals.

[edit] Technical problems

Macrovision is considered a nuisance to specialist users because it may interfere with other electronic equipment. If one were to run their video signal through a VCR before the television, some VCRs will output a ruined signal regardless of whether it is recording. This also occurs in some TV-VCR combo sets.

Apart from this, many DVD recorders mistake the mechanical instability of worn videotapes for Macrovision signals, and so refuse to make what would be perfectly legal DVD dubs of people's home old movies and the like. This widespread problem provides a legitimate basis for the sale of devices that defeat Macrovision.

The signal has also been known to confuse home theater line doublers (devices for improving the quality of video for large projection TVs) and some high-end television comb filters. In addition, Macrovision confuses many upconverters (devices that take a video signal and convert it to a higher quality signal), causing them to shut down and refuse to play Macrovision content.

[edit] Legal issues

Some DVD players give the user the option of disabling the Macrovision technology. This is possible since the signal is not stored on the DVD itself; instead commercial DVDs contain an instruction to the player to create such a signal during playback. Some DVD players can be configured to ignore such instructions.

There are also devices called stabilizers, video stabilizers or enhancers available that filter out the Macrovision spikes and thereby defeat the system. The principle of their function lies in detecting the vertical synchronization signal, and forcing the lines occurring during the vertical blanking interval to black level, removing the AGC-confusing pulses. They can be easily built by hobbyists, as nothing more than a cheap microcontroller together with an analog multiplexer and a little other circuitry is needed. Individuals less experienced with such things can purchase video stabilizers off the internet from companies. The best device for defeating Macrovision is a Time Base Corrector (TBC), although they are more expensive than the simpler video stabilizers.

Discs made with DVD copying programs such as DVD Shrink automatically disable any Macrovision protection. USB-based video interfaces designed to allow DVD recording on PCs are legally required to detect the presence of Macrovision signals on any analog signals input to them, and if so, inhibit the recording, but few, if any, do so.

The MPAA maintains it has every right to limit copying of movies, comparing DVDs to pay-per-view where the consumer is allowed to view the movie in question but nothing more. Many are concerned that the organization is attempting to quash fair use by disallowing consumers to make personal copies.

On the other hand the ease with which Macrovision and other copy-prevention measures can be defeated has prompted a steadily growing number of DVD releases that do not have protection of any kind, CSS or Macrovision.

United States fair use law, as interpreted in the decision over Betamax (Sony Corp. v. Universal City Studios), dictates that consumers are fully within their legal rights to copy videos they own. However, the legality has changed somewhat with the controversial Digital Millennium Copyright Act. After April 26, 2002, no VCR may be manufactured or imported without Automatic Gain Control circuitry (which renders VCRs vulnerable to Macrovision). This is contained in title 17, section 1201(k) of the Digital Millennium Copyright Act. However, there are a number of mostly older VCR models on the market that are not affected by Macrovision.

On October 26, 2001, the sale, purchase, or manufacture of any device that has no commercial purpose other than disabling Macrovision copy prevention was made illegal under section 1201(a) of the same controversial act.

[edit] SafeCast

Main article: SafeCast

SafeCast is Macrovision's software copy prevention technology for legacy computer applications. It is or has been used by such software packages as Intuit's TurboTax and many recent Adobe software products, and has occasionally been the source of controversy.

[edit] RipGuard

In February 2005, Macrovision introduced their new RipGuard technology. This is designed to prevent (or reduce) digital DVD copying by altering the format of the DVD content in such a way as to disrupt the ripping software. Macrovision claims that 97% of all current DVD rippers will not be able to copy a DVD protected by RipGuard technology. However, it can be bypassed with Slysoft's AnyDVD, Fengtao's DVDFab Decrypter, RipIt4Me, or MacTheRipper 3 for Mac OS X.

RipGuard also renders the formatted section of DVDs unwatchable on some players. The audio is intact, but the image appears scrambled. This has been confirmed with Toshiba DVD/TV combo model MD20FL1.

[edit] Cactus Data Shield

Main article: Cactus Data Shield

Cactus Data Shield (CDS) is a form of copy control for audio compact discs developed by Midbar Tech, now owned by Macrovision. There are several types, commonly described as CDS100, CDS200 and CDS300. However, there are about seven subtly different versions of CDS200. CDS200 discs are usually labeled as 'copy controlled' (CCCD). (They are formally not CDs). CDS300 discs are labeled as 'content protected'. CDS300 discs cannot be ripped by iTunes in particular. However, they contain copies of the music in low bit-rate WMA format, which allow to be burned to CD-R three times.

CDS300 was rebranded 'Totalplay' in 2005 and contained a Windows CD software driver that denied access to the audio portion of the music disc. Apple computers were immune to CDS300. However, it could still be ripped on the Windows platform by using the Musicmatch player. It exists today as an interesting legacy product that is incompatible with Apple's iTunes and iPod, products that are rapidly gaining customers.

CDS100 is incompatible with many CD players, particularly car CD players, which caused negative press around 2002. The company claims this was fixed in (modern versions of) CDS200, despite many users reporting otherwise.

[edit] CSS decrypting software

CSS decrypting software (such as DVD Decrypter, AnyDVD, Smartripper and DVD Shrink) allows a region-specific DVD to be copied as an all-region DVD. It also removes Macrovision, Content Scrambling System (CSS), region codes, and disabled user operations (UOPs).

[edit] Legal issues

In June 2005, Macrovision sent a cease and desist letter to "Lightning UK!", the maker of DVD Decrypter, a program that allows users to backup their DVDs by bypassing CSS and Macrovision. They later acquired the rights to this software and withdrew it from circulation on the internet.

In June of 2005, Macrovision sued Sima Products under section 1201 of the DMCA, claiming that Sima's video processors provided a way to circumvent Macrovision's analog content protection (ACP). As of June 2006, Macrovision received an injunction barring the sale of this device, while the court proceedings continue.

[edit] Notable acquisitions

  • In 2000, Macrovision acquired Globetrotter, creators of the FLEXlm, which was subsequently renamed into Flexnet.
  • In 2004, Macrovision acquired InstallShield, creators of installation authoring software.
  • In 2005, Macrovision also acquired ZeroG Software, creators of InstallAnywhere (direct competition to InstallShield MP (MultiPlatform)
  • In 2006, Macrovision acquired eMeta.
  • On January 1st, 2007, Macrovision acquired Mediabolic, Inc.

[edit] References

[edit] See also

[edit] External links

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