* * * * * * * * * * * * * * ------------------------------------------------------------------ c) by Marc Wielage. All rights reserved. Reprinted with permission from VIDEOFAX #5 (Spring '87). Information on subscriptions to VIDEOFAX is available from P.O. Box 481248, Los Angeles, CA 90048. ----------------------------------------------------------------- We've received literally dozens of letters from irate readers complaining about the new video copy-protection system, Macrovision, which is now being used as an anti-piracy method on most pre-recorded tapes. Here's just a sample: I've been renting videotapes and discs for years, and just discovered several tapes that flash, breakup, and look terrible on my VCR (a recent-model Panasonic) and monitor (a three-year old NEC). The titles include "Back to the Future," "Commando," and "Invasion U.S.A." Other copies of the same tapes have the same problem. Are they defective, or is this some new version of copyguard? -- Leon Hoffman, Secaucus, NJ Welcome to the world of Macrovision, Mr. Hoffman. Macrovision is the latest in a series of anti-piracy techniques, which began nearly a decade ago. In the mid-70's, a Hollywood video engineer named Jim Songer invented an anti-copying process called "Copyguard," which essentially weakened and altered the vertical sync signals in video recordings. If a dub of a Copyguard-encoded tape was attempted, the recorder had difficulty locking to the playback signal, and the resulting recording rolled uncontrollably and broke up every few seconds. Several similar sync-tampering systems soon followed, including "MV- Guard" from Mag Video and "SNID" from Bell & Howell, which added a serial number identification number to pre-recorded cassettes. All these processes eventually fell out of use, due to many complaints from consumers about instabilities during viewing -- that, plus the fact that these systems were only marginally successful at preventing copying. About five years ago, John Ryan, former director of engineering of the Ampex Corp., came up with an entirely different scheme, which he christened "Macrovision." Ryan's original process placed an unusual video signal just outside the picture, in the area known as the vertical interval. This original signal was a series of white box-like pulses measuring roughly 120 IRE on the video level scale; later, it was augmented with alternating black pulses measuring around -40 IRE on the scale, and they move back and forth, rhythmically, every few seconds. (In their technical brochure, Macrovision engineers refer to this signal as "a modulated plurality of bipolar pulse pairs during selected lines of the vertical interval" -- whatever that means.) You can easily see this signal by rolling down the image with the vertical hold control on your monitor, noting the white pulses at the extreme top and bottom of the picture. Here's what happens when you attempt to copy a Macrovision- encoded tape with two standard VCRs: first, when your recorder's automatic video gain circuit "sees" this non-standard signal, it attempts to turn the bright signal down to a normal level, which effectively ruins the video level of the main image by dropping it down into the mud, resulting in a dark, unstable, unwatchable copy. Secondly, the "blacker than black" alternating pulses interfere with the sync signals used by the VCR to stabilize the image, creating glitches and static. We've heard a variety of complaints about Macrovision, since it was introduced back in August of 1985, with the release of Embassy's "The Sure Thing". In an effort to quell the complaints, the company modified the original process and christened it Macrovision II, which was introduced last October. Most of the complaints we've received are from people who attempt to watch encoded programs on certain sets and projection monitors equipped with sensitive AGC circuits. These tend to make the Macrovision signal flash at the top of the screen and otherwise interfere with the regular image, making it dark or introducing vertical "shakes" into the picture. (Sometimes this effect can be reduced by bypassing any automatic color or brightness modes in the set, if these switches are provided.) This problem does not show up on our reference equipment, however -- specifically, Sony Profeel, Sony XBR, Pioneer, and Proton color monitors. Macrovision spokespeople insist that the vast majority of complaints they've received have been from people who have their equipment hooked up incorrectly -- such as those who try to watch movies playing back on VCR's already connected to other recorders or video accessories -- or, of course, people angry about not being able to copy tapes. So far, Macrovision has signed up half-a-dozen Hollywood studios to use this process on all their pre-recorded videocassette releases, including CBS-Fox, Disney, MCA, and MGM. The other majors, including Karl-Lorimar, RCA- Columbia, Thorn-EMI, Vestron, and Warner Bros., are expected to sign up shortly. Virtually all the major videotape duplication firms, including Bell & Howell, CBS/Fox Video and Teletronics, all have Macrovision encoding equipment available in their dubbing racks, and the cost of the process usually adds just a few cents per tape, in large quantities. While we can't condone videotape copying, which at this time is considered to be copyright infringement, we sympathize with anyone who is having problems watching pre-recorded programs. Our brief tests indicate that certain VCRs (including most Sony SuperBeta recorders and newer JVC HQ machines) have the ability to duplicate some Macrovision-encoded tapes with nary a problem. Alternatively, skilled technicians armed with the right tools and service manuals can defeat the video AGC circuit in many recorders. In addition, outboard accessories like proc-amps can be used to counteract the effect of Macrovision, with some limited success. (MFW demonstrated these techniques on coast-to- coast television several months ago, when interviewed on the Discovery Channel's "New Tech Times".) Even Macrovision officials admit that "as any video engineer knows, it is theoretically impossible to design a [copy- prevention] system that cannot be defeated." Already, several companies have announced Macrovision-eliminating units, which strip out the entire vertical interval and replace it with a normal black signal. Here's a brief list, arranged in order by retail cost, of several companies offering these devices: the "Line Zapper" from Elephant Electronics ($50 from Box 41865, Phoenix, AZ 85080, phone 602 581-1973); the "All-Guard Stabilizer" ($70 from Video Link, 12950 Bradley Avenue, Sylmar, CA 91342, phone 800 843-5465); "The Box" ($200 from Search Technology, Inc., P.O. Box 91, Pasadena, MD 21122, phone 800 237- 7644); DT Electronics' "Video Copyguard Killer" ($200 from 100 E. 12th St., NYC 10003); Vidicraft's recently-updated IVE-100 Integrated Video Enhancer ($200 from 0704 S.W. Bancroft, Portland OR 97201, phone 503 223-4884); and Showtime Video Ventures' "Universal Stabilizer" ($280 from 2715 Fifth St., Tillamook, OR 97141, phone 503 842-8841). We caution readers that we have absolutely no experience with these or any other dedicated anti-Macrovision device, and have no idea if they really work or not, so...caveat emptor. We do know that the Sansui AV-99 Special-Effects Generator (reviewed elsewhere this issue) has the unexpected bonus of totally removing the Macrovision signal, with the drawback of slightly degrading the sharpness of the video image. No doubt, other sophisticated video processors -- time-base correctors, broadcast proc-amps, and the like -- will accomplish the same thing, since they all replace and regenerate the vertical interval signal. Currently, the Macrovision process is incompatible with Laserdiscs, which already use the vertical interval for carrying special control pulses for the digital frame readout on all discs (along with other test signals). However, company officials advise that they're working on modified processes for use with all videodisc formats, and are also actively seeking to convince studios to use Macrovision to thwart people trying to record their TV shows and feature films off-air and from Pay TV -- a very disturbing thought, in our opinion. Macrovision is also working on a "high security encryption system" which will reportedly require a special decoder to view the tapes, which we expect will be used by studios to protect films and TV shows not yet released to the public. Gary Gwizdala, chief executive officer of Macrovision, advised us recently that their wide-range patents protect both the encoding AND the decoding process of their system, and that any companies selling devices designed to defeat Macrovision will be met with legal action very quickly. This runs contrary to a press release distributed last month by Showtime Video Ventures, which claimed that a recent patent investigation revealed two patents owned by Macrovision, both involving modifying the color burst signal to prevent copying. Curiously, neither of these processes has anything remotely to do with the existing Macrovision system, either for encoding or decoding. Questions and comments about Macrovision should be sent to the public relations departments of the home video divisions of the major studios and distributors. Readers are invited to send in their own comments on Macrovision encoding, which we'll pass along to the people involved.