Drums: How do I do it?

[Hoblit]

Necrothreading. You sick sick person.

I was never really all that worried about this but that's still some neat technology. I know that data has been watermarked for years but actual processing that can be taken from an analog source IS impressive. A lot of that type of technology is could be developed for all kinds of things. (My head IMMEDIATELY goes military on this one)

However, with any sort of decent audio watermarking it would be possible for, say, the RIAA to require companies selling DRM-free music to use pipe the file through a filter before it is downloaded. The downloaded song could then have an audio watermark that could be used to map it back to the service provider and internal account ID. This would mean it would be possible to go directly after the person that started sharing the music. If they're not doing this now, it is something you know they want to do.

Much easier would be to use differing watermarks for different presses of a particular CD. Even differing watermarks for differing regions of the same country are possible. It all depends on the level of paranoia, and I think the RIAA is willing to throw a lot of money at their paranoia...

Which is a shame because both of those methods are easy enough to thwart. They'd embed a code... hackers would develop a program to run all of your downloaded mp3s to either remove the code or change it. For every time they change it the hackers could offer a patch to the program. It'd be a lot of money down the tubes and only make the downloader' that much more angry at the system and that much more determined to keep their money out of it.

I don't know. I could be wrong. Maybe the RIAA could make it not 'worth the effort' but I somehow doubt it.

[jast]

I think the problem is that you'd have to know exactly what makes up the embedded code. If they've got a very fault-tolerant code, two differently watermarked files might look different in all places, and short of mangling you can't hope to ruin the code by accident.

[Rabid Garfunkel]

The part where this all seems to fall apart (for me) is the execution of the steganographic (thanks, Bill!) watermarks. I mean, sure, one could (conceivably) be dropping in all sorts of data into the non-audible (to human ear) frequency bands, say at the head and tail of the music file for uniformity's sake (like broadcast radio's promos over the tops & bottoms of new releases that they play), but what's the scheme for reading the data? Would it be every media playing device that's doing the "authorization" of the music (like, say, the PGP key system... media player has one part of the key, and the music file has the other, if they don't jive then it's the sounds of silence for you), or is this more an occasional "license & registration please/yes officer" encounter.

Either/neither/otherly way, it doesn't sound terribly cost effective *or* efficient. But that never stopped anyone before, heh (U.S.S.R. going tits up comes to mind here).

[Hoblit]

I think the problem is that you'd have to know exactly what makes up the embedded code. If they've got a very fault-tolerant code, two differently watermarked files might look different in all places, and short of mangling you can't hope to ruin the code by accident.

True, but that code would have to be matched by something else at some point or the file couldn't be played by ANYONE. They'll need customer's to be able to play the file. So it has to be identifiable in some way. I'm not arguing that it wouldn't be difficult.

EDIT:

The part where this all seems to fall apart (for me) is the execution of the steganographic (thanks, Bill!) watermarks. I mean, sure, one could (conceivably) be dropping in all sorts of data into the non-audible (to human ear) frequency bands, say at the head and tail of the music file for uniformity's sake (like broadcast radio's promos over the tops & bottoms of new releases that they play), but what's the scheme for reading the data? Would it be every media playing device that's doing the "authorization" of the music (...it doesn't sound terribly cost effective *or* efficient. But that never stopped anyone before, heh (U.S.S.R. going tits up comes to mind here).

EXACTLY.

[jast]

or is this more an occasional "license & registration please/yes officer" encounter.

That sort of stuff, yeah. If they discover a "pirated" version somewhere they can track it back to whoever illegally shared it.

Either/neither/otherly way, it doesn't sound terribly cost effective *or* efficient.

Once you've got a robust algorithm to do this stuff it's not that expensive, and robust algorithms are frequently developed for free by academics.

Here's a more or less concrete outline of how one might design such an algorithm. First, find a "subchannel" of the audio data that is inaudible, i.e. that you can hide a bitstream of information in. Don't tell anyone in precisely what part of the data you are hiding this bitstream (could be a specific frequency band or small alterations to every Nth sample or some freaky linear dependency stuff between the stereo channels... who knows).

Next, decide on a piece of information you want to embed into that bitstream. Use a lot less bits than are actually available. Optionally encrypt the information. Then, use an error correction code (e.g. Reed-Solomon, though there are much more effective choices like Turbo codes that I don't know much about). This gives you a random-looking bitstream of exactly the size that you can hide in the file. Now suppose you had k bits of information and encoded them into a bitstream of n bits. If an attacker of your algorithm manages to scramble less than (n-k)/2 bits of your bitstream, the watermark holds. For a practical example, suppose you encoded 24 bits of information into a bitstream of 1000. That means that the attacker would have to scramble at least 499 bits of your bitstream for the watermark to break. That's tough, especially if the bitstream is encoded into the file in different ways and you don't know all of them.

[Rabid Garfunkel]

Once you've got a robust algorithm to do this stuff it's not that expensive, and robust algorithms are frequently developed for free by academics.

Was referring more to the infrastructure required to police/enforce such a scheme/system than the actual nuts & bolts of the code, in re. "expensive". But yah, good points all.

[jast]

I think they're already doing way more expensive things that are way more pointless.

[mrbeany]

I certainly wasn't going in an "authorize to run" type of direction.

The other thing to remember is the metaphor they use. It is called a "watermark". It's deeply embedded in the product, and it has slightly fuzzy edges. How do you get rid of a watermark in, say, a $5 USD bill? I don't know how one would do it without severely damaging the bill.

The RIAA already spends massive amounts of money going after people who illegally share music. This sort of thing would make such attacks much more effective as you could go after a specific person and you could get a better idea of just how much money they owe you. It doesn't stop people from sharing the music, it just makes it more profitable (for the RIAA) when they catch someone, it also becomes much, much easier to catch people.

Basically, jast covered most of the other comments I would make, and thanks Bill for remembering that the other thing was called steganography.

Watermarking is similar to steganography, but different. It can be easy to destroy the message embedded with steganography. It is supposed to simply hide a message and accidental destruction of the message by a third-party is totally acceptable for most use-cases. The messages can even be fairly long. Watermarking, on the other hand, can only be used with much shorter payloads (think something like a serial number), and is specifically designed to be robust and hard to remove.

The watermarking basically acts like a signature allowing you to say definitively to a court, "I made this." Steganography, on the other hand, would allow you to plan for the destruction of a small government using USENET. (Like Tom Cruise's character in Mission:Impossible hiding a message in a longer USENET posting.)

[roymond]

Necrothreading. You sick sick person.

I was never really all that worried about this but that's still some neat technology. I know that data has been watermarked for years but actual processing that can be taken from an analog source IS impressive. A lot of that type of technology is could be developed for all kinds of things. (My head IMMEDIATELY goes military on this one)

However, with any sort of decent audio watermarking it would be possible for, say, the RIAA to require companies selling DRM-free music to use pipe the file through a filter before it is downloaded. The downloaded song could then have an audio watermark that could be used to map it back to the service provider and internal account ID. This would mean it would be possible to go directly after the person that started sharing the music. If they're not doing this now, it is something you know they want to do.

Much easier would be to use differing watermarks for different presses of a particular CD. Even differing watermarks for differing regions of the same country are possible. It all depends on the level of paranoia, and I think the RIAA is willing to throw a lot of money at their paranoia...

This is used today to track performances over many channel types (cable, satellite, broadcast, radio, internet streaming, etc.) They also know that 5 seconds of a 40 second source were used, etc. Royalties are paid, invoices sent (since they can prove commercials were aired when they were supposed to) and compliance is monitored.

Wasn't this thread about drums somehow?

[jb]

Now that you mention it, Roy:

Everybody get your random comments in now, 'cause I'm going to clear out all the off-topic stuff. Remember, this is the Help and How-To forum. Off-topic posts will be deleted at unpredictable times.

JB

[Me$$iah]

I dont like fish

[Hoblit]

I dont like fish

That's nothing compared to car parts.

[mrbeany]

I dont like fish

That's nothing compared to car parts.

Are you saying you don't like car parts?

Or that fish are not like car parts?

Or you've tried to put fish parts in your car and had a bad turn of luck?

[Caravan Ray]

I dont like fish

That's the problem with you lefty, liberal types. You are all icthy-haters.

"I know the human being and fish can coexist peacefully." — George W Bush, Saginaw, Mich., Sept. 29, 2000

[Hoblit]

I dont like fish

That's nothing compared to car parts.

Are you saying you don't like car parts?

Or that fish are not like car parts?

Or you've tried to put fish parts in your car and had a bad turn of luck?

No no no, nothing weird like that. I have an aquarium of used car parts sitting at the bottom of the tank. I hate them because they just lay there and do nothing.

[JonPorobil]

They'll help convert fossil fuels into kinetic energy if placed properly in a motor vehicle, but not if they stay in the bottom of your fish tank.

[Hoblit]

They'll help convert fossil fuels into kinetic energy if placed properly in a motor vehicle, but not if they stay in the bottom of your fish tank.

Its not a fish tank if there are no fish in it.

[mrbeany]

They'll help convert fossil fuels into kinetic energy if placed properly in a motor vehicle, but not if they stay in the bottom of your fish tank.

Its not a fish tank if there are no fish in it.

Technically an empty aquarium is filled with gases, making it a gas tank. Right?

So do you have a gas tank filled with car parts?

[Hoblit]

They'll help convert fossil fuels into kinetic energy if placed properly in a motor vehicle, but not if they stay in the bottom of your fish tank.

Its not a fish tank if there are no fish in it.

Technically an empty aquarium is filled with gases, making it a gas tank. Right?

So do you have a gas tank filled with car parts?

WHOAH ...slow down tiger, I never said there wasn't any water in it! Only that there were no fish. "Fish Tank" are your words.

[JonPorobil]

Nah, "fish tank" were my words. I happily withdraw them.

[Me$$iah]

That's the problem with you lefty, liberal types. You are all icthy-haters.

All Icthy-haters??really... see its always the same. You see conspiracies everywhere. All icthy-haters indeed.

hehe


Tho on a more serious note, I actually thought that you might agree with me on this. But then again. Its an environmental thing,and I'm sure you and your earth-hating types wont get it.

Its not just fish but whales too. Help save the world, kill all the damn fishes.
The sea levels are apparently gonna rise, so lets use science to defeat nature.
Archimedes anyone..... take out all the fish and whales, and the sea levels will go back down again. Surely this makes sense.


Oh yeh and it tastes bad, all fishy and yuk..

[Caravan Ray]

Its not just fish but whales too. Help save the world, kill all the damn fishes.
The sea levels are apparently gonna rise, so lets use science to defeat nature.
Archimedes anyone..... take out all the fish and whales, and the sea levels will go back down again. Surely this makes sense.

Yes, it makes perfect sense mechanically.

But I am just curious where are you going to put them all when you take them out?