Here's the scoop. I need to decode a wav file that I have. Let me tell you all that I know about it and see if anyone can lead me in the right direction.

The wav file contains (i believe) 100 bits of data that is transmitted over and over roughly 40 times a second. These values I am pretty sure of but the numbers are not definate. So these 100 data bits are encoded on this data stream somehow, that I don't know of.

I need a way to decode this wav file and extract these 100 channels so to speak. When I discover the method, I should be able to play the wav through my decoder and watch each channel 1-100 go high / low respectively ~ 40/sec.

I can see by looking at the wav file there is a start bit, so i think.. But what Im asking mainly is can anyone who's familiar look at this file and tell what method was used to encode.

Any help greatly appreciated!

http://www.dsfrobots.com/temp/filewav.zip

 

Ok so I'm pretty sure this is a Manchester encoded wav form. Can anyone at least verify this by looking at the wav form I included above? ANyone know of any good manchester decoder software I can run it through to see if I get any results.

 

As far as I'm aware a WAV file is pretty well a plain audio file, with some header information - if you google you should be able to find all the information about it.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

When I play the .wav file on my computer, I just get the sound. You need to convert the sound to an oscilloscope display and post that.

__________________
see my website: www.geocities.com/russlk

 

Im sorry!! I had assumed everyone could open it in an oscil. view themselves... here ya go...

 

It looks like a repeating pattern, not any kind of coding.

__________________
see my website: www.geocities.com/russlk

 

Well i know for a fact there is hidden in there 100 bits 40 times a second.. Just hoping someone could lead me in the right direction for extraction

 

Assuming it is a digital data sequence?, then you need to know how it's coded - it's no good just guessing (unless you have a LOT of time to spare).

However, for a start it's useless as an audio file - presumably it's from a modem?, so you need to convert it to ones and zeros to have somewhere to begin.

But you've never even mentioned what it is?, which will probably make a BIG difference!.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

It looks somthing like FM modulation to me

__________________
Il give you shocking experience.

 

Well that was the point to see if someone can guide me in the decryption. And what is it,, ITS a SECRET haha it is a streaming data that runs an animatronic robot.

I've counted 71 peaks between the common start bit which means to me that I must have lied about there being 100 bits here... Unless I've missed some logic in my head, to run 100 bits of data here I'd need 100 or more peaks wouldnt I?

So,, this is fun!

 

Why is it a WAV file?.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

because its played on 1 track while audio is played on the other track to sync movements to the sound.

 

OK, so at that point it's an audio track, you first need to convert it to a digital data signal - presumably it uses some kind of modem internally? (or at least the 'dom' part!). A simple modem method uses one tone for ONE and a second for ZERO, and you can demodulate it with a simple tone decoder PLL (like an NE567).

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

It does appear that there are two frequencies but sometimes the high frequency is only one cycle. I don't think a PLL will respond to that, but perhaps the one cycle in an anomaly and the system is not supposed to respond to that anyway.

__________________
see my website: www.geocities.com/russlk

 

Anyone familiar with CMI? I think it sorta resembles this type of coding... Either way, I have strong belief that the six short burst together have something to do with the start bit... then the short burst in between are indicating the 1's being sent. Sorta like CMI or Manchester.