KVR Audio

KingTuck · Post by **KingTuck** » Sun May 03, 2015 1:28 am

Alright. Many people might know that Tone2 embed an audio watermark into the phase of the output audio signal that contains some sort of license identification info for their products.

Many have talked about this and talked about why they don't care, many have talked about this and talked about why they do care. That's not what this thread is for.

I'm just wondering if anyone with some knowledge knows how feasible the retaining of this information is? Can information embedded into the phase of the audio signal live through rounds of external filter and EQ work? Am I mistaken in thinking that filters and EQ's change/disrupt the original phase of the signal in some way? Wouldn't running the output through pretty well any thick effect (heavy reverb or chorus perhaps) disrupt this info?

I'm really really really not going for any sort of flame thread here. I'm only wondering about the technical part of this. I'm interested in how this works. Whether or not it's a pipe dream, or truly a feasible method of monitoring license usage.

Please, no talk of whether you are, or are not, okay with audio watermarking! Let's keep this technical!

Aleatoriac · Post by **Aleatoriac** » Sun May 03, 2015 2:15 am

I don't understand how it could be worth the effort. But I'm no technician.

This is why I've never released any products, though I may get over my fear of loss of revenue from piracy and do it anyway.

I would think using a simple high pass filter (not linear phase) would mess anything like that up.

KingTuck · Post by **KingTuck** » Sun May 03, 2015 2:22 am

I feel too that it ought to be near impossible to retain any sort of audio watermark that doesn't find itself in the audible domain.

I would love to hear someone who would know what's-what on this topic chime in.

murnau · Post by **murnau** » Sun May 03, 2015 2:25 am

If you turn the phase it's retrography?

mehum · Post by **mehum** » Sun May 03, 2015 7:17 am

A Google search at least lets you read a few abstracts but they seem generally aimed toward water marking finished works. Without reading the full papers it's hard to discern what kind of manipulation does our does not destroy the water mark.

I don't think a water mark would be possible to get back from a moderately modified signal also masked by other sound sources.

Technologically very interesting, I doubt the developers will give out any information on the actual implementation so it's all speculation of course...

Judging from the abstracts and general psychoacoustic knowledge phase modulation done right should at least be inaudible even though it's theoretically in the audible domain.

Ben H · Post by **Ben H** » Sun May 03, 2015 7:26 am

Couldn't you and another friend just render the same MIDI file in the same DAW with the same settings and compare the two ?

Theoretically then your files should not match, because of different watermarks in each.
Realistically, I think I know what the results will be.

KingTuck · Post by **KingTuck** » Sun May 03, 2015 7:39 am

mehum wrote: I don't think a water mark would be possible to get back from a moderately modified signal also masked by other sound sources.

Seems this way to me too. That's why the idea of it potentially being feasible is so interesting. It's one of the topics that companies who implement it are tight lipped on, and those who don't are tight lipped also (perhaps to avoid confronting a competitors decisions in a public context? IDK).

murnau · Post by **murnau** » Sun May 03, 2015 7:53 am

This can't work anyway technically but let's assume it would and you collaborate with somebody over the net (What happen often nowdays). The other have a few stems which you then use (Oh no! They watermarked for this example but you dont know it, how you could? And the guy you worked with is located in Manila his name is Micky L. thats all you know).

You finish your track and who they could sue now? They can't prove you act illegally just because they found their watermark in your production. So let this where it belongs to.

PS. Of course it don't work anway, i'm just thinking about the impossibilty to sue the right person.

mehum · Post by **mehum** » Sun May 03, 2015 8:29 am

Ben H wrote:Couldn't you and another friend just render the same MIDI file in the same DAW with the same settings and compare the two ?

Theoretically then your files should not match, because of different watermarks in each.
Realistically, I think I know what the results will be.

Yeah, anything hidden in pain sight (...) like this would be theoretically reverse-engineerable.
It's hard to say if the differences would be discernable from the noise floor unless you know exactly what to look for...

Ben H · Post by **Ben H** » Sun May 03, 2015 8:40 am

EDIT: I'm not talking about audible differences.

You could easily checksum it or phase cancel it. That would give you a pretty clear indication of any small differences (if any at all).

mehum · Post by **mehum** » Sun May 03, 2015 9:34 am

Ben H wrote:EDIT: I'm not talking about audible differences.

You could easily checksum it or phase cancel it. That would give you a pretty clear indication of any small differences (if any at all).

I realized that, neither was I

Thing is, there's probably going to be some noise, quantization in the DAW or non-linearities in the oscillator algorithms, that would mask the phase modulation water mark. Unless you know the algorithm used it's probably close to impossible to know what's noise and what is water mark...

I don't actually think you'd need to have a friend to try it out either. Two instances will probably not insert the mark in exact timing. Even if it did, just make two different projects or bounce twice.

Ben H · Post by **Ben H** » Sun May 03, 2015 9:42 am

mehum wrote:I don't actually think you'd need to have a friend to try it out either. Two instances will probably not insert the mark in exact timing. Even if it did, just make two different projects or bounce twice.

That's a valid point.

UltraJv · Post by **UltraJv** » Sun May 03, 2015 9:44 am

Its quite possible that its smoke and mirrors. Tone2 might want you to think theres a watermark, there may not be.

KingTuck · Post by **KingTuck** » Sun May 03, 2015 6:39 pm

I doubt it's smoke and mirrors. If they were trying to scare people they could easily make up some gargon about it. Instead it's just mentioned in passing in the license info.

murnau · Post by **murnau** » Sun May 03, 2015 6:49 pm

KingTuck wrote:I doubt it's smoke and mirrors. If they were trying to scare people they could easily make up some gargon about it. Instead it's just mentioned in passing in the license info.

But thats it: They don't make a big thing out of it because it's utter nonsense. Do you read the answers here btw? What make you think this gonna work? Soundsample developers use watermark to identify when someone share the whole library. Once used in a track the watermark is useless and they can't follow back which lib was used.

Question about audio phase