There appears to be a few misconceptions about MacroVision?.
For a start there are a number of different levels of MacroVision, the standard, most common one, is the one that upsets the automatic recording level in VCR's. It doesn't alter the video signal itself, but it adds a varying height pulse at black level - EXACTLY where a VHS video measures the signal level to set it's gain (the back porch if I remember correctly?). So as the pulse slowly changes size, the VCR alters the gain to follow, giving the effect of the contrast on the recording changing.
As VCR's feed the signal through the gain circuit all the time, even E-to-E (feeding the signal through your VCR) produces this effect on your TV.
As a matter of interest, some Betamax VCR's measure the signal at a different point, and these were popular for copying MacroVision protected tapes years ago.
As for DVD's, it ISN'T inserted in the datastream, as there's no video signal it can't possibly be! - however, it does have a flag in the datastream - it's this flag that tells the DVD player to add MacroVision to the video output. So DVD players have a MacroVision encoder inside them, and the flag switches it on - some DVD players have the option to disable MacroVision, but it's not very many! - and it's hard to find how to do it!.
A also agree with most others, I don't see that your PS2 would add MacroVision to a game you're playing - there's no point?.