joegratz.net

SunnComm, the CD copy protection snake-oil vendors of “shift-key” fame, bought another vendor of CD protection snake oil, DarkNoise Technologies. DarkNoise claims to have developed a technology for audio CDs analogous to Macrovision for video signals, making the content unlistenable when copied via analog means.

What they claim isn’t entirely nonsensical. They say they have two methods of fouling up analog recordings of protected content. First, they include what they call “packets” — short bursts of audio intended to fool automatic gain control circuitry. That’s how Macrovision works. But you can’t see Macrovision pulses because they occur between frames in the video program, in what’s called the Vertical Blanking Interval. There is no such space in audio signals; any abrupt changes in level that would screw up AGC circuits would be audible (and really, really annoying).

Second, they include harmonics that create beats when recorded by analog means, but that they claim cancel each other out when a person is just listening. It might be possible to create a signal that would get fouled up by the filtering inherent in analog-to-digital audio conversion by placing harmonics right at the edge of the frequency range — for CDs, that would require loud harmonics at exactly 22.05KHz, which they’re hoping would turn into loud harmonics at 11.025KHz through imperfections in the filter. That might work. Maybe. On cheap analog-to-digital converter chips. But you’d be able to hear it on good equipment, and with good ears, even in the original. And I can’t think of any way you could foul up the analog-to-digital conversion that wouldn’t stand a good chance of also fouling up the digital-to-analog conversion. There might be some way to make it cancel out in the speaker, but not reliably; even if they could, you could just re-record with a microphone, which they claim you can’t do.

Regardless, a number of the claims they make are clearly false. For instance:

• On page 5 of the white paper, they claim that the technology will foul up conversions from CDs straight to WAV files. This cannot be so. A ripped WAV file is a perfect, bit-for-bit copy of the PCM audio data on the CD. If the CD plays perfectly, so will the WAVs; the exact same bits are hitting the sound card in each case.
• Also on page 5, they claim that the technology will foul up conversions from CDs to MP3s. On this page, they claim that “The embedded Q-Spoiler frequencies are placed according to The Psychoacoustic Model, i.e. beyond the audible response of the human ear.” MP3 compression works by removing all audio data not audible to the human ear, according to the same psychoacoustic model. Anything you can’t hear will get taken out; that’s how MP3 achieves such high compression ratios. MP3 encoding is likely to take out anything you can’t hear, which includes the copy protection frequencies. More importantly, the same page says that protected content can be distributed on MiniDisc. MiniDiscs use lossy ATRAC compression, which works in substantially the same way as MP3. There’s no way they managed to foul up MP3 encoding without fouling up ATRAC encoding.
• Even if this did work, it would reduce the audio quality significantly, by introducing unpleasant harmonics that cannot be counted upon to cancel each other out reliably.
• Let’s say you had the technology that DarkNoise claims they have. Let’s say it worked. You want to publicize your technology, so that people will buy it. Do you: (a) post a web page with a bunch of colorful graphs pretty clearly drawn in Adobe Illustrator and post a white paper with no real technical detail, or do you (b) maybe include a few audio samples, so people can hear your technology at work? This is an incredibly easy thing to demonstrate, if it works; you could even post before-and-after WAV files. And even if you needed to stick to your (dubious) story that WAV file encoding fouls up protected audio, you could at least include a sample of the fouled up audio to prove your point. But there’s nothing.

I think they’re bluffing. Whatever SunnComm paid, it was probably too much. (Of course, we’ll never know what SunnComm paid, since SunnComm is trading on the Pink Sheets and has elected not to report financial data to the SEC or its shareholders. Not a great sign.)