File safety

[geekdh]

I see a significant number of files posted as subliminals (even if they are labeled as MP3) without any script, and often with minimal descriptions. Based on the title and what description there is, I might be interested in at least exploring what they do.

But it seems to me that without a way to look at the content embedded in the file, I would really be opening myself to the possibility of bad actors sneaking nefarious content into file without my knowledge.

Is there anyway to extract the underlying content from a subliminal file?

[EMG]

That would depend on how it was made, any process can be undone if you know how it was done in the first place. Some subliminals are merely VERY quiet versions of the original so you can just up the volume. Others are done with special tools and you'd have to understand what they did to undo the process.

[geekdh]

EMG,
I think I’ve seen you make a statement at some time in the past that, if you download files from WMM and use them in modified, they will be safe. My mind is just wondering what steps you take to make sure that’s true if you don’t know what is in the content.

Have you ever considered a policy requiring script files if the content is not readily intelligible?

[Fizbin]

I can't vouch for all of the subliminal files here, but most of the files by Trainer, who owns the Dreamgirls site that regularly advertises here, do pretty much what they say on the tin.

His files, and many others, use an encoding technique called single-sideband modulation (yeah, just like an old CB radio) to shift the audio into the near-ultrasonic range. (There's an old analog patent for the process, but it expired years ago...)

This block of Nyquist code can be used in audacity to shift the file back into the regular audio range:

Code: Select all

(setq carrier 14500)
(lowpass8 (mult 2 s (hzosc carrier)) 8000)


You may need to play with the carrier frequency (17500 is also a common number)

They are also recorded at a very low volume, so you might need to amplify it back in order to hear the results.