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Hidden-Feature DVD Players Again
FModnar writes: "As described in this review on DVDfile.com, another DVD player has been found that exhibits the same menus as the Apex DVD player did a few months ago. Some of the 'hidden' features include the ability to turn off region coding and Macrovision." Sounds like this is a higher-quality player, too. Since both of the Apexes I bought failed within weeks and had to be returned, I certainly hope so. If enough players are region friendly, "chipping" may never catch on much in America.
I understand the excitement about getting rid of the region coding on the DVD system. But I wouldn't get too enthused about getting rid of Macrovision; you can do that yourself with a soldering iron and about $20 in Radio Shack parts. And no, I don't have a schematic to share, but if you're interested, I'll tell you how it works.
Unlike most of the discussions here which revolve around digital systems and digital technology, Macrovision is analog.
VCRs, just like cassette decks, have to have a recording level set, so that the tape is neither under-recorded or oversaturated. The appropriate recording level varies by scene and by source; all video signals should in theory have a specific level, but in practice, they don't. Therefore, there must be some compensating mechanism.
VHS VCRs (but not Beta, 3/4" or other professional formats) set their recording level using the black level in the "vertical interval", which is the black bar that you see when your vertical hold control is set wrong. There are scan lines there, and they contain a sub-black pulse that is sent to the vertical oscillator in the TV set to reset it to the top of the frame. But, a lot of the vertical interval is just video black, and is there because early TV sets needed a couple of lines to recover from the vertical reset.
As TV sets became more advanced and the need arose to hide more stuff into a TV picture, the vertical blanking interval has been used for lots of extra things: most notably, closed captioning, pay TV decoder controls, and setting record levels on home VCRs.
Try rolling your picture sometime and see if you can get it to stay on the vertical interval. You'll see a couple of bars flashing around for closed-captioning, and a couple of other bars flashing around that would provide digital signals to turn on and off older addressable analog pay-TV decoders (if your cable company uses them). (Usually, this stuff is in lines 19 and 21, odd fields only, but this depends on the cable company.)
VHS VCRs use black lines to set the record level. I can't remember the line numbers specifically, but it's line numbers in the teens.
If you want to prevent a VHS VCR from recording properly, therefore, all you need to do is screw with the blackness that should be present. If you replace it with white bars and stripes, the VCR will set its recording level low, and the rest of the frame of video will appear dark when you play it back. If you flash it on and off, the VCR will compensate during recording and flash the image bright (normal) and dim. Macrovision also screws with the recorded color indirectly; because the chrominance information's record level is generally set by the amplitude of the colorburst pulse at the start of each scan line, it will appear that the colors get to be too intense (saturated) for the given brightness (luminance) of the picture.
Okay, that's how it works. And, only VHS VCRs are vulnerable (and older/cheaper TV sets that don't properly deal with having crap in the vertical interval). So, how do we kill it?
Simple. What you need to do is detect the Horizontal and Vertical sync pulses, and make sure they always get through to the TV set. That's easy, they're the only things that should be between 0 and 0.3V (out of 1 volt of video). So, selectively filter out anything above 0.3V.
Set up a PLL or something to watch for the 60Hz pulse in that sync stream you've just found. A good chip to do this is the National Semiconductors LM1881 Sync Separator chip. Pin 3 will give you an output that you can use to reset a counter. Throw together a counter circuit using TTL or CMOS logic that will count 23 horizontal sync pulses (pin 1) after the vertical pulse from Pin 3. Once the counter has counted that many lines, you need to make it pass the video. You've now made a 23-line-long vertical pulse - your TV might or might not cope with it, your VHS VCR definately won't (but it won't hurt anything).
Now, all you need to do is, in the time that the counter is counting those 23 lines after reset, you hold the video output to your VCR to 0.3V. Congratulations, you've just scrubbed Macrovision from your video.
I figure about four commonly-available chips and a small power supply. I tried it myself a few years ago using just the LM1881, a counter, and about 6 transistors. I built my Macrovision scrubber not to make VHS copies of movies, but because I collect 1950s and 1960s TV sets, and many of them don't play well with Macrovision, and I still want to be able to watch rented movies on them.
Another trick that works sometimes is to just run the video into the video in jacks on a Beta VCR, and run the recovered video out. Most VCRs, while they're just idling, rebuild the sync pulses and intervals (this is why a lot of older VCRs don't pass closed captioning info to your TV). Since Beta VCRs set their recording level a different way, they're immune to Macrovision.
Fire and Meat. Yummy.
One thing I've not seen addressed in the whole copyright debate - what rights does a DVD owner have when the copyright on a DVD they own expires?
For example, 50 years or so from now when The Matrix enters the public domain, will Macrovision magically turn itself off? Will the DVD decss itself? Will it magically become region free?
If you take the long view, there is a real legitimate reason for technology (and hidden menus) that get around technological copy protection.
chris
This page on DVD Reviewer has a list of DVD players, and how to multi-region hack them! :-)
In theory, it's actually in a manufacturers interests to make a DVD player crackable. Think about it. If the coders "accidently" leave in a hidden menu that can be used to crack the player and make it region free, then someone in the company "leaks" how to do it, people take notice.
:)
As a good example, i bought my Samsung player on the very basis that it was easy to crack so i could play the Region 1 DVD's in Region 2. Another good example is several well known UK supermarkets were selling players that could be easliy cracked, and told the buyers how do it. The players flew off of the shelves.
The easier it is to crack the player, the more people will want one.
Syllable : It's an Operating System
Flaming Weasels
Yeah. You read that right. Flaming weasels. Now, you might just dismiss this as some sort of delusion, but I ask you, have you ever been attacked by flaming weasels? If you have, you realize this is no joke. There is no hiding from flaming weasels. No escaping. Once the weasels have been sent, there is no turning back, and you may as well just disclose your proprietary closed-source sock drawer, because the weasels must be appeassed.
And here we are talking about new players which are going to break down in a couple months, but tell me, does that make the threat of weasels any less real? And who do you think the armies of flaming weasels are going to be sent to first, Joe Compliant who buys his standards-compliant dvd player, shops at wal-mart and votes democratic? Of course not, he's part of the Master Plan(tm). The weasels are going to be sent to "take care" of the deviants, the people who watch foreign films, the people who disable life saving features in their dvd player, the people who want to remake the world in their own way, not the time-warner-dvdcca-ms-mcdisney way. And the weasels will continue to attack until you or I or SOMEONE does something about it.
There is one hope. There is one possible salvation, one glimmer of light in the dark night of the weasel, though not too dark, as that they're on fire, and fire does make a little bit of light yanno. The weasels aren't exactly subtle. You're going to know they're coming, which in a way, is much worse. We only have one chance to defeat this scourge and take back the rights that we have so willingly sacrificed.
It is time for RoboMow(tm)
Bad things often happen to good people,
It is up to them to see that they remain good.
Within a few years it will probably be hard to find any players that only support a single region code.
I've seen some posts here saying that 'The DMCA said so, and you have to live by that.'
Yes. If you're an American. This is not just an American forum though. There are actually countries where region locking is considered anti-competitive and hence illegal. Look at New Zealand. It's only because the American public willing surrender their rights little by little, that you're prepared to live with this.
In other places, there is nothing remarkable about this player. In South Africa, most shops will show you the region beating features before you take the player out the door. I had three different sales people explain the region-defeating features of three different players, in one afternoon.
/* Wayne Pascoe