zahid@mozart.amd.com (Zahid Ahsanullah) (07/20/90)
I seems to be having problems recording movies vcr-vcr. What happens is that the recording vcr receives some signal from the replaying vcr that either removes the blanking pulse, distorts it, or messes up the sync pulse. I may be wrong entirely but atleast I'm sure that the signal is tampered with to prevent recording. I don't know why anyone would want to do that since it's for only home use, but I want to get around it. The symptoms are if you are viewing from the recording vcr end, a slight but periodic change in the brightness of the screen. This is not the case if you just want to view the movie. Any of you guys got any circuits out there? Really appreciate it. Zahid
depolo@eniac.seas.upenn.edu (Jeff DePolo) (07/25/90)
In article <1990Jul19.222558.7820@mozart.amd.com> zahid@mozart.amd.com (Zahid Ahsanullah) writes: >The symptoms are if you are viewing >from the recording vcr end, a slight but periodic change in the >brightness of the screen. This is not the case if you just want >to view the movie. > >Any of you guys got any circuits out there? Really appreciate it. > > Zahid The varying brightness is characteristic of MacroVision, one of the better anti-duplication schemes. You may also notice a horizontal bar that moves from the top to the bottom of the screen on your duplicate tape. In any event, MacroVision can be defeated. You can buy copy boxes for about $50 that will take care of the problem or you can build one yourself. Supposedly there was a recent article in Radio Electronics (I think) that had the plans for one. Total on the parts would probably run close to $30 or so anyway, so it may be easier just to buy one. Look in the back of Radio Electronics, Video Magazine, Video Review, etc. to find ads for these things. --- Jeff +-----------------------+-----------------------------------------------------+ | Jeff DePolo N3HBZ | Internet: depolo@eniac.seas.upenn.edu | | Univ. of Pennsylvania | RF: 146.685- 224.40- 442.70+ 144.455s (Philadelpia) | | Computer Science Eng. | Twisted pair: (215) 386-7199 home | | Class of 1991 | Carrier pigeon: 420 South 42nd St. Philly, PA 19104 | +-----------------------+-----------------------------------------------------+
berryh@udel.edu (John Berryhill) (07/25/90)
What you want is a video duplication enhancer. There are several models available and they all work fine. Ask your friendly consumer electronics salesman. -- John Berryhill 143 King William, Newark DE 19711
zahid@mozart.amd.com (Zahid Ahsanullah) (07/25/90)
I'd like to thank Chia-Chi Chao and `dplatt' (sorry couldn't find a name there) for their vcr recording help. Mail doesn't seem to work today. Thanks for the circuit DP. Regards Zahid
zahid@mozart.amd.com (Zahid Ahsanullah) (08/03/90)
This is for Paul L. Moreau who wanted a copy of the schematic for the macrovision decoder. I can't seem to get email through to him so I'm posting it here. Hope it works for you Paul. Regards Zahid
zahid@mozart.amd.com (Zahid Ahsanullah) (08/03/90)
Sorry my original post got cut short. Here's the schematic someone sent me. It has not been tested so I can't say if it works. I don't claim any responsibility for the contents of this article so use at your own risk. ---------------------------- From: mark@cygnet.CYGNETSYSTEMS (Mark Quattrocchi) Subject: Macrovision Eliminator Date: 16 Jun 88 23:24:38 GMT Well here it is. Since I've had so many request for this goody I thought I'd just post it instead. This Macrovision Eliminator is about as good as I can get it. It has a bandwidth well over 10mhz and should be able to drive a number of devices in parallel. For those who plan to make one I must warn you that I take no responsibilty for anything (my disclaimer :-)). I have tried it on a number of different tapes, VCRs and TVs so it should work good for everybody. Have fun!!! Yeah, I can finally rent tapes again! Notes: This also eliminates time codes and close caption information. Sorry about the cryptic schematic but what can you do when all you have is ASCII to work with. If you don't see a + at an intersection it isn't connected. ____________ | LM1201 | Video 10uf 16| |12 In >-----+--+--||---+--------------------|In Vcc2|--------------+--<+12v | | + | 1N914 3| |15 200 | | | +--|<|--+------------|Vref Vcc1|------/\/\/---+ Video | | | .1uf | |10 75 | In >------------>Gnd +--||--+ | Vcc3|------/\/\/---+ | | 75 | | | | +--------------/\/\/---+ | | | 10k | | |13 .1uf +12v>--------+---/\/\/--------------+ | Cont.C.|------||------+ | | |Gain | 4| | | | | +----------------------|Contrast | | | | 10k | | |14 | | +---/\/\/--------------+ | Cont.C.|--------------+ | | |Offset | 6| | | | +----------------------|Clamp+ | | | 5.1k 43k | | | | +---/\/\/---+--/\/\/---+ | | | 1000pf | | 5| |11 51 | +----||-----+----------------|C.G. Drive|------/\/\/---+ | | | 8| |2 .1uf | +-----------------+----------------|Out Ccap|-------||-----+ | | | | 75 | | |7 | | | | +--/\/\/---+ | Gnd2|--------------+ | | | | 200 | 9| |1 | | | | +--/\/\/---------|Clamp- Gnd1|--------------+ | | | | |____________| | | | | | A1 | Gnd>--------------------------------+---------------------------------+ | | | | | | | | +------------------------------------+ | | ____________ | | | | LM1881 | | | | 8| |1 | | | +12v>---|Vcc Csync|----------+ | | .1uf 2| |5 | | | +-----------||------|In Burst|------+ | | 680 6| |3 | | +--/\/\/-+--------|Rset Vsync|------+ | | | .1uf | 4| |7 | | | +---||---+ +---|Gnd Field|- | | | | | |____________| | | | | | A2 | | | | | 450 750 | | Gnd>--------+-------------+--/\/\/---+---/\/\/----+ | | | | | +-------------+ | | | | | +-----------------------------------------+ | | | | | | ____________ | | | | 74LS221 | | | | 1| (1/2) |16 | | +------|A1 Vcc|----<+5v | | 2| |13 | | +5v>---+---|B1 Q1|------+ | | | 3| | | | | +---|Rst1 | | | | .1uf 14| __|4 | | |Position+--||----|C1 Q1|- | | | 10k | 15| | | +5v>----------/\/\/--+--------|R/C1 | | | | | | |____________| | | | +----+ A3 | | | +--------------------------+ | | | | | | ____________ | | | | 74LS221 | | | | 9| (1/2) |8 | | +------|A2 Gnd|---<Gnd | | 10| |5 | | +5v>---+---|B2 Q2|------------+ | | | 11| | | | | +---|Rst2 | | | | .1uf 6| __|12 | | | Width +--||---|C2 Q2|- | | | 10k | 7| | | +5v>-----------/\/\/--+-------|R/C2 | | | | | | |____________| | | | +----+ A3 | | | 750 450 | | +--/\/\/-----+----/\/\/---<Gnd | | | | | +----------------------------------+ | | | | | | | ____________ | | | | | 74LS221 | | | | | 1| (1/2) |16 | | | +----|A1 Vcc|----<+5v | | | 2| |13 | +5v>-------+------------------|B1 Q1|- | | | | 3| | | | | +--------|Rst1 | | | | .01uf 14| __|4 | | |EQ.Start +--||----|C1 Q1|------+ | | | 20k | 15| | | | | +--/\/\/--+--------|R/C1 | | | | | | |____________| | | | +----+ A4 | | | +--------------------------+ | | | | | | ____________ | | | | 74LS221 | | | | 9| (1/2) |8 | | +------|A2 Gnd|---<Gnd | | 10| |5 | | +5v>---+---|B2 Q2|- | | | 11| | | | +---|Rst2 | | | 1000pf 6| __|12 | | EQ.Width +--||---|C2 Q2|------+ | | 20k | 7| | | | | +5v>--/\/\/--+-------|R/C2 | | | | | | |____________| | | | +----+ A4 | | | | | | +------------------------------------+ | | | | | +-------------------------+ | | | | | | ____________ | | | | 74LS00 | | | | 1| |14 | | +-----|In1 Vcc|-----<+5v | | 2| |3 | +----------|In2 Out1|------+ | 7| | | | Gnd>-------|Gnd | | | |____________| | | A5 | | +------------------------------+ | | ____________ | | | LF1333 | | | 4| |5 | Gnd>---------------|Gnd V-|-----<-12V | | 16| |12 | +----------|In1 V+|-----<+12v | | 14| |15 10uf 75 | +---------------|S1 D1|-----+--||---/\/\/----->Video Out | | | 1| | | + | | +----------|In2 | | Gnd>--------->Video Out | | 3| |2 | +----------------------|S2 D2|-----+ | |____________| | A6 | +12v>----/\/\/--<Gnd 5k Blanking SOME NOTES: You can replace some of the pots with fixed resistors if you like. The OFFSET pot can be replaced with a 7.85k to +12v and a 1.43k resistor to ground. The POSITION pot can be replaced with a 6.25k resistor. The WIDTH pot can be replaced with a 6.81k resistor. The BLANKING pot can be replaced with a 4.18k resistor to +12v and a 592ohm resistor to ground. I do not recommend replacing any of the other pots with fixed values. If you do use fixed resistors please skip those steps in the adjustment procedure. TIMING DIAGRAM AND ADJUSTMENT PROCEDURE: Set up: Connect a scope up to the video input and trigger on vertical sync. Make sure you can still see past the Macrovision pulses. The second channel will be used for looking at the device being adjusted. Pre-adjust all pots for center position. 1. Connect the 2nd channel on the scope up to A1-pin8. 2. Adjust GAIN for 1 volt peak to peak output. 3. Adjust OFFSET for a 1-2 volt DC offset. 4. Connect the 2nd channel on the scope up to A3-pin13. 5. Adjust POSITION so the falling edge of the signal is in the middle of the horiz. line just before the Macrovision pulses (see timing). 6. Connect the 2nd channel of the scope up to A3-pin5. 7. Adjust WIDTH so the falling edge of the signal is in the middle of the horiz. line just after the Macrovision pulses (see timing). Macrovision |<------------------->| ||||| ||||| ||||| ||||| _______ ____________|||||_|||||_|||||_|||||________ Video In | |_____|_____|_____| | ||||||||||||||||||||||||| | _______ ___________________________________________ Vsync (A2-pin3) |_________________| __________________________ Q1 (A3-pin13) ___| |__________________________________ ______________________________ Q2 (A3-pin5) ______________________________| |___ __ _________________________________________________________________ Q1 (A4-pin12) | | | | | ______________________________ ___ Out (A5-pin3) |__|_____|_____|_____|_____|___| ________ ___________________________________________ Video Out | |_____|_____|_____| | | | | | | | 8. Connect the 2nd channel of the scope up to A4-pin4. 9. Adjust EQ.START so the rising edge of the signal is just after the single Macrovision Burst (see timing) 10. Connect the 2nd channel of the scope up to A4-pin12. 11. Adjust EQ.WIDTH so the signal is low during the equalization pulses and goes high just after the color burst signal (see timing). 12. Connect the 2nd channel of the scope up to Video Out. 13. Adjust BLANKING level to match the rest of the videos blanking. 14. The video output should now look like Macrovision never existed. 15. Try it! A Single Macrovision Burst |<--------------------------------->| _ _ _ _ _ _ _ | | | | | | | | | | | | | | _________ _ | |_ | |_ | |_ | |_ | |_______ _ | |_ | |_ Video In |_| |_| |_| |_| |_| |_| |_| |_| |_| | _______________________________________________________________ Q2 (A3-pin5)___| __________ _ ___ ___ ___ ___ _________ _ ___ ___ Csync (A2-pin1) |_| |_| |_| |_| |_| |_| |_| |_| |_| | __ __________ ____ Q1 (A4-pin4) |__________________________________| |________________ __ __________ ___________________________________ ____________ Q2 (A4-pin12) |___| |___| If there is anything I forgot to mention or is unclear (I know, too late) send me mail and I'll try to clear it up. Mark Quattrocchi From: mark@cygnet.CYGNETSYSTEMS (Mark Quattrocchi) Subject: Macrovision Eliminator Date: 11 Jul 88 00:05:21 GMT I hope I didn't miss too many questions about my macrovsion eliminator while our news feed was down. If so please repost or send me mail. I did receive a couple of questions and thought I'd post instead of mail. Some people are having problems getting the National Semi LM1201, and I thought I'd explain. The LM1201 is new and will be in production shortly (well thats what they tell me :-)). I got mine from the first sample run. Since some of you are trying to build this goody I figured I'd send you another version that does not use that part. Also I modified the schematic so you can use a single supply voltage (though you smart folks would have figured that out anyway). A voltage between 16-35vdc will run this, however if you use a supply over 24vdc you will probably need to add a heat sink for the voltage regulators. I'd like to thank Bill McFadden for the DC restorer circuit which I show as the LM1201 replacement (hope it works Bill :-)) and left his article in tact by only appending the rest of the macrovision circuit to his DC restorer. For those who plan to make one I must warn you that I take no responsibilty for anything (my disclaimer :-)). I can't speak for Bill but you can ask him yourself. I hope he doesn't mind me doing this!?!? Notes: This also eliminates time codes and close caption information. Sorry about the cryptic schematic but what can you do when all you have is ASCII to work with. If you don't see a + at an intersection it isn't connected. All voltages used on A1-A6 are supplied by the two voltage regulators shown at the bottom of this schematic. Just a note: The op amp used below must be a video op amp like the RCA CA3100. C | | VIDEO IN O------+------| |------+----------------+---------------+ | | | | | | | | |\ ___ | | | | \ / \ (DIODE) | +----/\/\/\-----+----|- \ | | R | >----+ | +----|+ / | | | / | | |/ | ___ | /// | | +------------------------------------------------------------+ Video | In >-----+ | | Video | | In >------------>Gnd | | | | | | | | ____________ | | | LM1881 | | | 8| |1 | | +12v>---|Vcc Csync|----------+ | | .1uf 2| |5 | | +-----------||------|In Burst|-- | | 680 6| |3 | | +--/\/\/-+--------|Rset Vsync|------+ | | | .1uf | 4| |7 | | | +---||---+ +---|Gnd Field|- | | | | | |____________| | | | | | A2 | | | | | 450 750 | | Gnd>--------+-------------+--/\/\/---+---/\/\/----+ | | | | | +-------------+ | | | | | +-----------------------------------------+ | | | | | | ____________ | | | | 74LS221 | | | | 1| (1/2) |16 | | +------|A1 Vcc|----<+5v | | 2| |13 | | +5v>---+---|B1 Q1|------+ | | | 3| | | | | +---|Rst1 | | | | .1uf 14| __|4 | | |Position+--||----|C1 Q1|- | | | 10k | 15| | | +5v>----------/\/\/--+--------|R/C1 | | | | | | |____________| | | | +----+ A3 | | | +--------------------------+ | | | | | | ____________ | | | | 74LS221 | | | | 9| (1/2) |8 | | +------|A2 Gnd|---<Gnd | | 10| |5 | | +5v>---+---|B2 Q2|------------+ | | | 11| | | | | +---|Rst2 | | | | .1uf 6| __|12 | | | Width +--||---|C2 Q2|- | | | 10k | 7| | | +5v>-----------/\/\/--+-------|R/C2 | | | | | | |____________| | | | +----+ A3 | | | 750 450 | | +--/\/\/-----+----/\/\/---<Gnd | | | | | +----------------------------------+ | | | | | | | ____________ | | | | | 74LS221 | | | | | 1| (1/2) |16 | | | +----|A1 Vcc|----<+5v | | | 2| |13 | +5v>-------+------------------|B1 Q1|- | | | | 3| | | | | +--------|Rst1 | | | | .01uf 14| __|4 | | |EQ.Start +--||----|C1 Q1|------+ | | | 20k | 15| | | | | +--/\/\/--+--------|R/C1 | | | | | | |____________| | | | +----+ A4 | | | +--------------------------+ | | | | | | ____________ | | | | 74LS221 | | | | 9| (1/2) |8 | | +------|A2 Gnd|---<Gnd | | 10| |5 | | +5v>---+---|B2 Q2|- | | | 11| | | | +---|Rst2 | | | 1000pf 6| __|12 | | EQ.Width +--||---|C2 Q2|------+ | | 20k | 7| | | | | +5v>--/\/\/--+-------|R/C2 | | | | | | |____________| | | | +----+ A4 | | | | | | +------------------------------------+ | | | | | +-------------------------+ | | | | | | ____________ | | | | 74LS00 | | | | 1| |14 | | +-----|In1 Vcc|-----<+5v | | 2| |3 | +----------|In2 Out1|------+ | 7| | | | Gnd>-------|Gnd | | | |____________| | | A5 | | +------------------------------+ | | ____________ | | | LF1333 | | | 4| |5 | Gnd>---------------|Gnd V-|-----<Gnd | | 16| |12 | +----------|In1 V+|-----<+12v | | 14| |15 10uf 75 | +---------------|S1 D1|-----+--||---/\/\/----->Video Out | | | 1| | | + | | +----------|In2 | | Gnd>--------->Video Out | | 3| |2 | +----------------------|S2 D2|-----+ | |____________| | A6 | +12v>----/\/\/--<Gnd 5k Blanking __________ | 7805 | | +12v | 16-35VDC>---------+------------|In Out|-----+-------+------>+12v | | | |+ | GND>----------------+-----|Gnd | === === | | |__________| |10uf |.01uf | | | | | +----------------------+-------+------>Gnd | | __________ |10uf |.01uf | | | 7805 | === === | | | +5v | |+ | +------------|In Out|-----+-------+------>+5v | | | +-----|Gnd | |__________| SOME NOTES: You can replace some of the pots with fixed resistors if you like. The OFFSET pot can be replaced with a 7.85k to +12v and a 1.43k resistor to ground. The POSITION pot can be replaced with a 6.25k resistor. The WIDTH pot can be replaced with a 6.81k resistor. The BLANKING pot can be replaced with a 4.18k resistor to +12v and a 592ohm resistor to ground. I do not recommend replacing any of the other pots with fixed values. If you do use fixed resistors please skip those steps in the adjustment procedure. TIMING DIAGRAM AND ADJUSTMENT PROCEDURE: Set up: Connect a scope up to the video input and trigger on vertical sync. The second channel will be used for looking at the device being adjusted. Pre-adjust all pots for center position. 1. Connect the 2nd channel on the scope up to A3-pin13. 2. Adjust POSITION so the falling edge of the signal is in the middle of the horiz. line just before the Macrovision pulses (see timing). 3. Connect the 2nd channel of the scope up to A3-pin5. 4. Adjust WIDTH so the falling edge of the signal is in the middle of the horiz. line just after the Macrovision pulses (see timing). Macrovision |<------------------->| ||||| ||||| ||||| ||||| _______ ____________|||||_|||||_|||||_|||||________ Video In | |_____|_____|_____| | ||||||||||||||||||||||||| | _______ ___________________________________________ Vsync (A2-pin3) |_________________| __________________________ Q1 (A3-pin13) ___| |__________________________________ ______________________________ Q2 (A3-pin5) ______________________________| |___ __ _________________________________________________________________ Q1 (A4-pin12) | | | | | ______________________________ ___ Out (A5-pin3) |__|_____|_____|_____|_____|___| ________ ___________________________________________ Video Out | |_____|_____|_____| | | | | | | | 5. Connect the 2nd channel of the scope up to A4-pin4. 6. Adjust EQ.START so the rising edge of the signal is just after the single Macrovision Burst (see timing) 7. Connect the 2nd channel of the scope up to A4-pin12. 8. Adjust EQ.WIDTH so the signal is low during the equalization pulses and goes high just after the color burst signal (see timing). 9. Connect the 2nd channel of the scope up to Video Out. 10. Adjust BLANKING level to match the rest of the videos blanking. 11. The video output should now look like Macrovision never existed. 12. Try it! A Single Macrovision Burst |<--------------------------------->| _ _ _ _ _ _ _ | | | | | | | | | | | | | | _________ _ | |_ | |_ | |_ | |_ | |_______ _ | |_ | |_ Video In |_| |_| |_| |_| |_| |_| |_| |_| |_| | _______________________________________________________________ Q2 (A3-pin5)___| __________ _ ___ ___ ___ ___ _________ _ ___ ___ Csync (A2-pin1) |_| |_| |_| |_| |_| |_| |_| |_| |_| | __ __________ ____ Q1 (A4-pin4) |__________________________________| |________________ __ __________ ___________________________________ ____________ Q2 (A4-pin12) |___| |___| If there is anything I forgot to mention or is unclear (I know, too late) send me mail and I'll try to clear it up. Mark Quattrocchi