Question about Watermarks

vbimport

#1

Okay, this whole addign watermarks to audio tracks is kinda confusing me…

Whats the point? Sure it might stop pre-release leaks… or at least encourage analogue dumps. But how will this stop people from ripping them once they are in stores? Not like you have to buy them online through them. There is no way to control or know who has what copy.

Besides the internet is based on the 1= infinite copies. Copy controlling a cd in every country but one does nothing. Its faster now to just DL tracks I want from mirc / kazaa whatever then waiting for a friend to bring it over.

I would rather order a cd with out copy control from Canada and wait a week then buy it with the hassle of having to rip it. I got ‘the music’ cd without knowing it was copy control(it had an ‘enchanced’ cd logo on it, but no CD logo):Z Ripped it and returned it. I have an MP3 player which has gov’t tax on it that goes to the industry, but i still can’t use it?

Parker…

ps. Whats with the PLAYER.exe on some of these files? Itll play them at 44k? Doesnt the indursty understand that if people could play it at 128K they would complian less.? and its still ‘copy control’


#2

Sorry about the rant… Im just confused on how this watermark or adding info into tracks will stop copying or ripping?

It sounds like to me another way to send virus around… hidden inside mp3s…

Parker


#3

The thing is not to block the copying , but to arrest the initiator of the one who put it on the internet in as the first.

The watermark will help to identify the original owner/reciever of the music.

Say for instance you are working at some radio station JWXL and you get lots of promotion cd’s from Sony.

They give you this nice cd and you decide that it’s cool to put it on Kazaa. So you convert it to mp3/ogg/wma/whatever and everyone starts leeching it.

Now if Sony finds out , they will try to extract the watermark from the file and identify it to you. So , to say in the least , you’re a suspect on distributing copyrighted material on the internet.

Perhaps you’re arrested , perhaps not , but in many cases your job might be in great jeopardy and your credibility towards Sony might have gone to zero. No more promotion materials for you.

Funny thing is , they say this watermark “survives” encoding , reencoding and rerecording , no matter if it’s audio or digital.

But the fun thing of mp3 for instance is that it usually removes all the sounds the human ear can’t hear anyway. So if this is to be a correctly working watermark , it must be somewhere inside the audio spectrum of the normal human ear to still be inside that mp3 file.

I dunno about the algorithms for .ogg and .wma , but i’m pretty sure they don’t differ that much from the Frauenhofer mp3 encoding techniques.

Perhaps it’s already doomed , because if they can embed a watermark in it then people can also come up with a bit-by-bit comparison to see where the watermark may be.

At first you can be cautious. Grab a promo cd and a normal cd and start comparing these two. They should be somewhat identical except the watermark and maybe some other bytes. Then get rid of those bytes and reencode the result.

Who knows ?


#4

There is one all too likely possibility.

A very low level of “noise” added to the music. The noise will be different for each individual CD.

While re-recording, re-encoding, compressing, ect may add far greater levels of noise, it will still be detectable.

You just:

A) Lock the recording to an original by matching the music waves. This avoids timing problems due to the copy being played back at a slightly different speed.

B) Subtract the music, as far as is possible.

C) take each sample of the recording (the digital 44,100 samples per second) and multiply it by the “noise” from the corresponding sample of the suspected original, and add all together.

If the noise is truly random, the result of the accumulated bits will average out at a low number. If it belongs to the suspected CD, the result will be strongly positive.

You do not have to check hundreds of thousands of possible noise signatures. You could add, say, any combination of 32 different noise signatures, and read them as a 32 bit binary number, giving about 4,000,000,000 possibilities.


#5

Example 1 : you buy a song from mp3.com, giving your name, address, cc number, etc.
Before you can download it, mp3.com watermarks the song with these informations.
Later, you share it on kazaa and some riaa guy get it from you, decodes the watermark,
and you get sued.

Example 2 : you rip a watermarked song from some audio cd and play with it in
Soundforge, add some funky beat, a few instruments or voices and try to sell it
as your own. Your fans check the watermark and immediately see that the song
is an illegaly modified copyrighted product.

Example 3 (in a near future) : you rip a watermarked song from a new audio cd
you bought and share it on kazaa. Someone gets it from you and tries to burn
it : unfortunately, his brand new drive recognizes the ‘don’t burn’ watermark
and simply refuses to burn this song.

Preventing illegal distribution, tampering, copying : 3 applications of watermarking.