rkj@ides.UUCP (Rick Janka) (02/28/86)
I have recently purchased a vcr (VHS) and have used it for playing rented tapes and recording a few broadcast movies. I am aware that something called Copyguard exists, but I know next to nothing about it. If I borrow a friend's vcr and attempt to copy a rented tape, will I get garbage? One dealer I spoke with said that he has not run into problems with recording rented tapes, but that Copyguard typically prevents copying tapes borrowed from a public library. I assume that a tape I record myself, from whatever source, could be copied without problems, though maybe that is incorrect. I'd appreciate any enlightenment, but please don't waste your fingers on flames regarding legalities; I am interested only in the technical aspects. Rick Janka ihnp4!ides!rkj
brown@nicmad.UUCP (03/03/86)
In article <161@ides.UUCP> rkj@ides.UUCP (Rick Janka) writes: >I have recently purchased a vcr (VHS) and have used it for playing rented >tapes and recording a few broadcast movies. I am aware that something >called Copyguard exists, but I know next to nothing about it. If I borrow >a friend's vcr and attempt to copy a rented tape, will I get garbage? One >dealer I spoke with said that he has not run into problems with recording >rented tapes, but that Copyguard typically prevents copying tapes borrowed >from a public library. I assume that a tape I record myself, from whatever >source, could be copied without problems, though maybe that is incorrect. > >I'd appreciate any enlightenment, but please don't waste your fingers on >flames regarding legalities; I am interested only in the technical aspects. 'Copyguard' hasn't been used on VHS tapes in a few years. The term implied the technique of changing the vertical sync, a little bit, so that the tv would still display it without rolling and the copying vcr would have trouble recording it. But, as the vcrs got better, most table top units would record correctly ANY tv signal that was even close in the vertical sync. I have been through two table top units where that is what would happen. A portable model of one of the table top units would still record the tape, but the head switch-over point could be seen wandering though the picture. Not exactly what the duplicators wanted. Plus, there are companies making devices that would replace part of the bad sync so that the recorders that wouldn't record the signal would. So, as time went on the duplicators dropped the 'copyguard' technique on VHS tapes. Beta machines, especially ones made by Sony, still wanted perfect vertical sync, so they tended to not record any picture if 'copyguard' was used. A couple of people I know ran into this problem. They have cheaper units, so I don't know what the top-of-the-line Beta decks do with damaged vertical sync. But, here is the newest killer to video tape copying: Macrovision. It is a technique whereby the AGC circuit of VHS decks is fooled. The vertical sync is not damaged. What is done is that during the vertical blanking area (the lines that following the vertical sync, up until the picture starts again) is changed. Right after the color burst pulse the video signal is sent to horzontal tip level and then to white level. About 7 of these transitions occur for about 5 lines worth. The sharp transition from horizontal sync tip to white level messes with the AGC circuit of a majority of machines. Also, about 7 lines before vertical sync and for 3 lines of the vertical sync, the area that is used for the color burst (know as the back porch), is sent to white level. This technique does not work on Beta machines, as the AGC circuit design is completely different. It also doesn't work on all VHS machines either. CBS Fox has recently announced that all product will be released with the 'Macrovision' anti-copy technique. Supposidly something like 5 million units. The next question is probably; how do the duplicators get around this signal. The company that makes the 'Macrovision' signal modifies all of the slave VHS machines, so that the AGC circuit is fixed and no longer operational. Obviously the cure for home machines is to modify the machines so that the AGC circuit is also fixed. The other way is to build a circuit, with a handfull of parts, that locks onto the sync and then replace the changed video area with good video signal. Since there are all kinds of sync separator chips out there, it would be an easy job. I personally feel that CBS Fox is wasting their money and ours, as will will ultimately pay the price in the cost of each tape. Because so many units will be shipped, the video enhancer manufacturers will build the above described circuit into their boxes. The above discussion doesn't indicate that I support copying of rented tapes. I am always interested in what the companies try and do to stop people from copying tapes. It is like a puzzle. I like to solve electronic puzzles. I have to laugh at the latest venture, as it won't be long before this one is beaten as well. There is nothing that somebody can design that someone else can un-design. When it somes to video, there isn't much that can be done to make it unrecordable. -- ihnp4------\ harvard-\ \ Mr. Video seismo!uwvax!nicmad!brown topaz-/ / decvax------/
fish@ihu1g.UUCP (Bob Fishell) (03/04/86)
> I have recently purchased a vcr (VHS) and have used it for playing rented > tapes and recording a few broadcast movies. I am aware that something > called Copyguard exists, but I know next to nothing about it. If I borrow > a friend's vcr and attempt to copy a rented tape, will I get garbage? "Copyguard" isn't used much any more. What it did was to snip off part of the sync pulse, on the theory that it would cause a pirated copy to roll uncontrollably. Since it also messed up older TVs and could produce a jittery picture even on newer sets, it wasn't very well received. Besides, it's ridiculously easy to defeat with any sync stabilizer, an after-market component that restores to the sync pulse what copyguard snips off. They're about $60 nowadays. The kind of copy you get from a rental tape (or any other tape, for that matter) depends on the condition it's in. If the original is in good shape, you'll get a good copy. Some rental tapes, especially ones of very popular films, get beat up in short order, and yield lousy copies. I've rented tapes that had been so chewed up by previous renters that I couldn't watch them, let alone copy them (I recently rented a copy of "Rambo" that must have gone to 'Nam with him). Almost everything that comes out on videocassette will be available on HBO, etc., within a year. If you've got cable, you might just want to wait until they broadcast the movie you want; you'll usually get a better copy that way. -- __ / \ \__/ Bob Fishell ihnp4!ihu1g!fish
ryan@ucla-cs.UUCP (03/04/86)
In article <161@ides.UUCP> rkj@ides.UUCP (Rick Janka) writes: >I have recently purchased a vcr (VHS) and have used it for playing rented >tapes and recording a few broadcast movies. I am aware that something >called Copyguard exists, but I know next to nothing about it. If I borrow >a friend's vcr and attempt to copy a rented tape, will I get garbage? One >dealer I spoke with said that he has not run into problems with recording >rented tapes, but that Copyguard typically prevents copying tapes borrowed >from a public library. I assume that a tape I record myself, from whatever >source, could be copied without problems, though maybe that is incorrect. I think i have had a run-in with Copyguard. I once tried to copy "Rambo" which ended in despair. The sound came out ok, but there was no video. Any idea on how it works? -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= | _R_y_a_n_ _R_a_m_s_e_y _H_o_m_e_ _P_h_o_n_e- (213) 391-2888 | | | | _A_R_P_A- ryan@ucla-locus.arpa | | _U_U_C_P- ..!{sdcrdcf,ihnp4,trwspp,ucbvax}!ucla-cs!ryan | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
heneghan@ihlpf.UUCP (Heneghan) (03/04/86)
> > I have recently purchased a vcr (VHS) and have used it for playing rented > > tapes and recording a few broadcast movies. I am aware that something > > called Copyguard exists, but I know next to nothing about it. If I borrow . . . > Almost everything that comes out on videocassette will be available on HBO, > etc., within a year. If you've got cable, you might just want to wait > until they broadcast the movie you want; you'll usually get a better > copy that way. > Bob Fishell > ihnp4!ihu1g!fish An alternative would be to find a video rental store that doesn't do a lot of volume, especially if you have a hifi deck and want to tape in hifi. Joe Heneghan
jimb@tekcbi.UUCP (Jim Boland) (03/05/86)
In article <563@nicmad.UUCP>, brown@nicmad.UUCP writes: >Beta machines, especially ones made by Sony, still wanted perfect vertical >sync, so they tended to not record any picture if 'copyguard' was used. >A couple of people I know ran into this problem. They have cheaper units, >so I don't know what the top-of-the-line Beta decks do with damaged vertical >sync. I disagree. I have never (yep, an all inclusive word - but it is true in this case) had any problem in copying a tape with copyguard on Beta. I was dubbing from a Sony SL5400 to VHS or other beta machines. I have had trouble dubbing from some VHS machines, but never beta machines. The machines I used for Beta were all Sony's - SL 5200,5400, 5600, 5800, 2700, 2710. The tapes were marked as having copyguard on them and you could tell some were. However, they dubbed just fine with no external gadgets or add-ons. I always dubbed video-video, never RF. Note: these dubs were never kept. Call it "delayed to be shown at a more convenient time".
brown@nicmad.UUCP (03/06/86)
In article <534@tekcbi.UUCP> jimb@tekcbi.UUCP (Jim Boland) writes: >In article <563@nicmad.UUCP>, brown@nicmad.UUCP writes: >>Beta machines, especially ones made by Sony, still wanted perfect vertical >>sync, so they tended to not record any picture if 'copyguard' was used. >>A couple of people I know ran into this problem. They have cheaper units, >>so I don't know what the top-of-the-line Beta decks do with damaged vertical >>sync. > >I disagree. >I have never (yep, an all inclusive word - but it is true in this case) had >any problem in copying a tape with copyguard on Beta. I was dubbing from >a Sony SL5400 to VHS or other beta machines. I have had trouble dubbing from >some VHS machines, but never beta machines. The machines I used for Beta >were all Sony's - SL 5200,5400, 5600, 5800, 2700, 2710. The tapes were >marked as having copyguard on them and you could tell some were. However, >they dubbed just fine with no external gadgets or add-ons. I always dubbed >video-video, never RF. >Note: these dubs were never kept. Call it "delayed to be shown at a more > convenient time". You have been lucky. Not all people have, like the ones that I know here. In the case I mentioned, the user did have trouble. Maybe the newer machines are getting better. BTW, the from machine won't matter. It is the recording machine that makes the difference. I once had to swap the from/to machines, to get around the problem. Besides, the old 'copyguard' technique is dead, as far as VHS machines are concerned. The new 'Macrovision' method is coming around. But, for you Beta people, 'Macrovision' does not work. It is only a method that works on about 50% of the VHS machines (the 50% quote is from the 'Macrovision people). Since the old 'copyguard' still works on some Beta machines, that may stay around a while. The easiest way to see if either copy protection method is being used, is to use the vertical hold control and bring down the black horizontal bar. Do it during the black leader of the tape. You will then be able to see if there is any kind of protection. If you see any text characters, that isn't it. 'Copy guard' will change the vertical sync, while 'Macrovision' will have about 5 or 7 white boxes right after the vertical sync. I say white boxes, as the result will end up looking that way. -- ihnp4------\ harvard-\ \ Mr. Video seismo!uwvax!nicmad!brown topaz-/ / decvax------/
billk@tektronix.UUCP (Bill Kenworthy) (03/06/86)
In article <354@ihlpf.UUCP>, heneghan@ihlpf.UUCP (Heneghan) writes: > . > > Almost everything that comes out on videocassette will be available on HBO, > > etc., within a year. If you've got cable, you might just want to wait > > until they broadcast the movie you want; you'll usually get a better > > copy that way. > > Bob Fishell Not always. It depends on the quality of the signal you get on the cable. If the cable signal is noisy, if the solid colors (i.e. blue) have little black noise dots or whatever - as on my cable system-- then I'd rather stick with the VCR. I also get stereo that way. HBO is currently not in stereo. They don't send it out in stereo from New York. Currently, only Movie Channel has stereo. > > An alternative would be to find a video rental store that doesn't do a > lot of volume, especially if you have a hifi deck and want to tape in > hifi. > Joe Heneghan And preferably in Beta Hi-Fi. Less time base errors. Particularly noticeable on big screens.
brown@nicmad.UUCP (03/07/86)
In article <6765@tektronix.UUCP> billk@tektronix.UUCP (Bill Kenworthy) writes: > HBO is currently not in stereo. >They don't send it out in stereo from New York. Currently, only Movie Channel >has stereo. HBO is distributed in digital stereo. A direct result of the M/A Comm Cypher IIencoding/decoding system. But, not all cable companies (mine included) do not put up the stereo audio on the FM band. The Movie Channel has been stereo for alot longer and has had a better chance of getting on a system in stereo. One of the guys at our head-end put up HBO on the FM band, while it was still mono. After the scrambling went 24 hours, he put in the spare stereo exciter and we had stereo. But, the powers that be said that it had to be pulled, as further study was needed. For no extra cost we had stereo. Oh Well!!! -- ihnp4------\ harvard-\ \ Mr. Video seismo!uwvax!nicmad!brown topaz-/ / decvax------/
mdf@osu-eddie.UUCP (Mark D. Freeman) (03/12/86)
Summary: In <6765@tektronix.UUCP> billk@tektronix.UUCP (Bill Kenworthy) writes: >HBO is currently not in stereo. >They don't send it out in stereo from New York. Currently, only Movie Channel >has stereo. I am a subscriber [of|to] Warner-Amex Qube in Columbus, and we get HBO, TMC, and Showtime simulcast (in stereo) on the FM band. We also get some out of town radio stations, as well as great receptions on the locals. I set my VCR to simulcast, and record HBO in glorious Super BETA-HiFi. -- < < < < < < < < < < < < < < < < < < < <> > > > > > > > > > > > > > > > > > > > Mark D. Freeman mdf@osu-eddie.uucp StrongPoint Systems, Inc. mdf@osu-eddie.arpa Guest account at The Ohio State University !cbosgd!osu-eddie!mdf I speak, therefore I disclaim everything I say. < < < < < < < < < < < < < < < < < < < <> > > > > > > > > > > > > > > > > > > >
speaker@ttidcb.UUCP (Kenneth Speaker) (03/12/86)
In article <6765@tektronix.UUCP> billk@tektronix.UUCP (Bill Kenworthy) writes: >In article <354@ihlpf.UUCP>, heneghan@ihlpf.UUCP (Heneghan) writes: >> . >> > Almost everything that comes out on videocassette will be available on HBO, >> > etc., within a year. If you've got cable, you might just want to wait >> > until they broadcast the movie you want; you'll usually get a better >> > copy that way. >> > Bob Fishell >Not always. It depends on the quality of the signal you get on the cable. >If the cable signal is noisy, if the solid colors (i.e. blue) have little >black noise dots or whatever - as on my cable system-- then I'd rather stick >with the VCR. I also get stereo that way. HBO is currently not in stereo. >They don't send it out in stereo from New York. Currently, only Movie Channel >has stereo. > Yes, my cable signal looks like it has been through the GI track of a 3 month old baby--several times. By the time it has gone through umpteen repeaters, jillions of taps, and 50 miles of aged cable, it looks pretty bad. >> >> An alternative would be to find a video rental store that doesn't do a >> lot of volume, especially if you have a hifi deck and want to tape in >> hifi. >> Joe Heneghan >And preferably in Beta Hi-Fi. Less time base errors. Particularly noticeable >on big screens. Huh? Why does Beta Hi-Fi have less time base errors? (I am a Beta fan, but don't understand.) --Kne