Can AudioKey Survive Dragon's Fiendish Review Process?
I decided to put AudioKey through a kind of "torture test". I used a music file I was very familiar with, since I performed on it, recorded it, and mixed it myself, and which is a particularly good test file because it has a number of silences in it.
First, I took the original stereo WAV file, encoded a message in it, and decoded it. No problem there. Then I edited the WAV file in Sound Forge XP, adding a few seconds of silence to the beginning, chopping some time off the end, and changing the overall volume of the song. The message still decoded fine.
Now I decided to get serious. First I tried compressing it to RealAudio. AudioKey was able to extract the message in a single operation...still no challenge. Aha, said I...everybody's always complaining about MP3 being the preferred format of music pirates, and everyone knows it's a "lossy" compression scheme.
So, using a couple of audio tools I happened to have laying around on the disk, I first converted the file to 128 Kbps MP3 (which took it from a 15.75 MB file to just 1.5 MB) and then back to WAV format.
AudioKey still read the message.
Impressive, as Darth Vader would say. But I wasn't finished. Now I took that same WAV -> MP3 -> WAV file and burned it to a CD, then extracted the file from the CD. Big deal, you say...putting it on a CD is the same as storing it on a hard disk. Except that I extracted it as audio! I played the CD in a CD player program, and recorded the audio through analog connections, converting it to WAV via the sound card. If you're keeping score, that's digital to analog to digital.
And AudioKey still read the message.
Even all this might not be that amazing except for one thing. I couldn't hear a single artifact, glitch, or anything that could be attributed to AudioKey's embedded message...and believe me, I listened!
But Wait, There's More!
There seemed to be one catch, though. When I did a digital extraction of the track from CD, I found a serious Rice Krispie problem (snaps, crackles, and pops). I scratched my head for quite a while over this one, then recorded the original track (without the embedded message) to CD and extracted it, and it had the same problem! Luckily, I was able to track this down to the digital extraction program that came with my CD-R drive, because another program (CDex, which is not only wonderful, but free) worked fine (I say luckily because it could have been the CD burning program that caused the pops!). So AudioKey had nothing to do with the noise.
But I wasn't quite finished. No, if this review was going to deserve the name "torture test", AudioKey was really going to have to sweat for it.
This time I took the track that I had brought in via analog and converted it to Microsoft's Windows Media 4.0 format, which Cognicity has no support for whatever, since the format is so new. I used the 64 Kbps setting, which definitely changes the sound (no easy CD transparency for this test!). Since there are no programs yet which convert Windows Media to WAV, I simply re-recorded it via the sound card, converting from digital to analog to digital again.
And AudioKey still read the message.
It sweated this time, taking about 5 minutes to sync up, and a few of the first characters it read were a bit off. But there was enough clear text left in a 1½ minute song to put the evildoers behind bars, or whatever.
I performed all the above using AudioKey's "robust" mode, but to cover all the bases, I also did most of the tests over (including going from WAV to MP3 and back, and doing the analog import) using the "standard" mode in Layer 1, which is the only mode supported in the "Lite" version. Still worked fine.
Conclusions and Kudos
At this point, I'm convinced that AudioKey could probably read the embedded data if I sent it between two paper cups with a piece of string between them. I'm not impressed easily (and that goes double for hearing noise, or not, in my own music!), but this was a heck of a demonstration, and it wasn't just at a trade show, this was in my own studio with my own equipment.
The interface is a bit funky, but it makes up for that by being written in Java and therefore portable. Cognicity has come up with a product that does everything it should, and it's priced where you don't have to be CDnow to afford it. If you're thinking of releasing any music tracks onto the Web, AudioKey (or AudioKey Lite) is the way you can protect, mark, and track them.
If you've read this far, you deserve to at least have the chance of hearing the song...if you're a parent, you'll definitely get a kick out of it! Click here for RealAudio, or here for the Windows Media version (you'll need the new Microsoft Media Player beta).
Yes, that's me on guitar, bass, and MIDI drums, my wife Susan on vocals (the real one is in the right channel, all the others are synthesized), and my son Steven doing everything else. Originally recorded on a TASCAM 424, mixed to HiFi VHS, digitized in Sound Forge XP, and converted to streaming format using Sonic Foundry's Streaming Anywhere. And yes, there's a message encoded in it...what's the matter, can't hear it? :-)
(If you want to hear some encoded classical music in a real live WAV file, click here)