regarding watermarking:
although nothing is done with the projected movie,i was reading somewhere that where the cinema screen is,either one or more 'bright infra-red' lights is shone into all of the audience areas which interferes with the camcorder (all the camcorder can 'see' is this bright light shining into it.the human eye cant see this infra-red shining light,but the camcorder is sensitive to it).
it was summat like that anyway.
This does sound like a way to stop camming, maybe it's being done.
But watermarking is somewhat different and a lot meaner than that. There have been so many speculations around about what watermarking actually is...
1. Audio: for those of you who don't know what a DCT (Discrete Cosine Tramsform - a fourier related transform) is: imagine a continuous, clean 440Hz (a) sine wave, something that could come out of an ideal, perfect wooden flute.
The DCT will transform this signal from its time domain to its frequency domain. That does sound a little like science fiction talk about "scotty, invert the deflector's phase and reroute energy through the Heisenberg compensators", but it's pretty simple: the result is a long series of zeros and a single peak value at - well? - 440Hz, right.
And you can imagine, how you can compress the hell out of this single information.
Now you know, why this type of transform is so commonly used in compression scemes like MP3 and MPEG (ok, it gets a little more complicated with "real music and speech").
Because there is always a backward transform that will restore my 440Hz sine wave from the information "440Hz and nothing else", it runs both ways.
Now about watermarking: if you're clever enough, you can modify the information in the frequency domain in a way that it will show a certain pattern that can be detected later on - while it will still go unnoticed when listening to the sound.
In case of the sine wave above it will probably not be possible, but this really is not the typical soundtrack of a movie, right?
If the pattern is complex enough, it will be very improbable that it will "accidentally" show up in non-watermarked material, especially not over a longer period of time (like a whole second).
One thing to note: "inaudible" in this context is usually being taken too literally. A very basic requirement is, that the watermark must be at least near the audible range, because that's what our speaker systems are made to reproduce. Otherwise the watermark would be simple to cut off too.
It will usually even be right in the middle of our audible frequency range. So you really can hear it, you just can't notice it (or at least hardly can).
2. Video: not much to say here. You can treat a black and white image as a two-dimensional signal and pass it through a 2D variant of the DCT. The same applies here, just that your watermarking pattern can be 2-dimensional - even sort of a "picture" in the frequency domain (which will transform into some slight noise in the visible time domain).
The "cure" to both watermarking schemes would be simple: wipe out the sound and the video and the watermark is gone. But so is the movie.
So, what you have to do is cut out the watermark with a scalpel, resulting in as little damage in audio/video as possible. This requires either knowledge of the pattern or the knowledge of it's position in the stream or ideally both.
So, whoever feels up to the task - whenever they start coming up with watermarking and you're first to send us working code, that kills the watermark with little "collateral damage", there's probably a nice pay check waiting
Hey, maybe even I'm lucky and it's me. Then I'll get the paycheck.... that I'd get anyway, .... well, .... that's life....
I would be mad if I bought AnyDVD-HD and could not decrypt newer discs with these new security measures but I could understand. Slysoft has not won the battle yet with AACS.
Is this about winning a battle? We're aiming to supply a tool that will ideally always allow you to do with your bought content whatever you like.
And as long as it is not pumping it up to torrents, we even feel good about it.
But I have no illusion, that we're ever going to "win the battle" in a sense that AACS will draw back and quietly say "we retire, thanks for the fun". They want the money badly.
