Disabling ATI Macrovision detection

"Macrovision" is a simple (but nevertheless patented) copy-prevention technique which is used on many commercial videotapes and pay-per-view TV channels. It works by manipulating the signal in a way which confuses most (though not all) VCRs, while displaying without problems on most (though not all) TVs. A typical symptom of trying to record a Macrovisioned signal on a consumer VCR is that the recording will get alternately brighter and darker, making it difficult to watch. You will also be bitten by Macrovision if you try to feed a video signal through a VCR on its way somewhere else (for example, if you want to connect your DVD player to your TV via your VCR).

Macrovision doesn't work at all on digital-video hardware like the ATI All-In-Wonder series. You'd think ATI would see this as a competitive advantage, but for some reason they wrote a Windows driver which specifically looks for the Macrovision signal and cripples video capture if it detects it. A typical symptom of trying to capture a Macrovisioned signal on an All-In-Wonder card is that the capture file will look fine for a while, and then suddenly the video will seem to "stick," with the last few frames repeating over and over.

The offending driver is called "atinmdxx.sys" on my machine. Properties|Version identifies it as "ATI Specialized MVD VBI Codec." VBI stands for Vertical Blanking Interval, where the primary Macrovision signal is found, and I suppose MVD stands for MacroVision Detection. Video capture won't work at all without this driver present, so you can't just delete it. But, as usual, it can be rendered harmless by changing a single conditional jump instruction to an unconditional jump. That's what the DisableATIMacrovisionDetection program does.

This program has many perfectly legal uses. Copyright law grants you broad freedom to make copies for personal use of a video that you have lawfully purchased. What is illegal under copyright law is distributing copies, not making copies. The corporations which use copy-prevention technologies don't care about your rights, and that's fine: they're not supposed to. Unfortunately, the democratic governments of the world, which are supposed to look out for your rights, have been negligent here: they haven't outlawed Macrovision or DVD encryption. Until that happens, you will have to make do with tools like this.

Usage

To use the patcher just run it. It will locate the appropriate driver automatically.

If that doesn't work you can try to locate the driver yourself. It should be called either "atinmdxx.sys" or "ativmdxx.sys". Once you've found it, drag it on top of the patching program's icon and it'll start up and patch it. (Be sure you're enabled "show hidden files" in Explorer, or you won't be able to see the driver file.)

You will probably have to reboot to activate the patched driver.

Caution

Unfortunately, the Macrovision detection driver loads at startup (at least in Windows 2000). If something goes awry, your system might no longer boot after running this program. In case you have problems, the patching program saves the original driver in a file with the ".ori" extension, in the same directory as the patched driver. You should be able to boot up in safe mode and replace the broken driver with the original one.

Compatibility

I have only tested this program with Windows 2000 and the All-In-Wonder 128 16MB.

This program definitely will not work under Windows 95, because the driver that I patch is not supported by Windows 95. I don't know if there's some other Macrovision detector on those platforms, but I used to capture with VirtualDub and the old VfW capture driver and I never had any problem with Macrovisioned tapes.

This program ought to work under Windows 98, ME, and Whistler, but I haven't tested it.

TV-Out

Along with checking its video input for Macrovision, the All-In-Wonder cards also apply Macrovision to the TV output (if it's enabled) when you play DVDs. This patch does not disable TV-Out Macrovision.

Legal

This program (source, executable and documentation) is in the public domain and comes with NO WARRANTY. Run it with the expectation that it'll crash your system; then you'll be pleasantly surprised when it doesn't.