Transferring Data Through Audio

[amrcidiot]

I don't know if any of you guys have seen this, but some guy figured out a way to transfer data using audio (almost like a morse code sort of deal).

Link is here:
Awesome Geek Blog: File transfer over sound card

It's pretty amazing to imagine the increase of piracy if this would become a popular method of transmitting data. However, I don't know how slow/fast it sends files.

 

[Chathurga]

It's pretty amazing to imagine the increase of piracy if this would become a popular method of transmitting data.

How could this possibly lead to an increase in piracy.

 

[Crank]

How could this possibly lead to an increase in piracy.

Yeah, it is beyond me. But anyway, this is nothing new - I remember reading about some guy dumping the firmware of one of the first iPods with this kind of trick.

 

[Moose]

Yeah, but this won't become a popular method of transferring data, so I don't see it becoming a popular form of piracy.

 

[Chathurga]

Yeah, but this won't become a popular method of transferring data, so I don't see it becoming a popular form of piracy.

It already was a popular form of transferring data: modems.

 

[MenaceInc]

I don't know if any of you guys have seen this, but some guy figured out a way to transfer data using audio (almost like a morse code sort of deal).

Link is here:
Awesome Geek Blog: File transfer over sound card

It's pretty amazing to imagine the increase of piracy if this would become a popular method of transmitting data. However, I don't know how slow/fast it sends files.

Sample rate (-r) increases the processing time, but it also allows faster transfers. There are a few fixed possible sample rates, 8000 always works, others that are supported by most soundcards are 11025,16000,22050,24000,32000,44100 and 48000

I'm guessing that with a sample rate of 48Khz and with quickly skimming over the code that the maximum transfer rate is roughly about 35KB/s... :\

 

[Moose]

It already was a popular form of transferring data: modems.

Modems used sound cards to transfer data? I never knew that.

 

[Chathurga]

Well they used sound:
[yt]X9dpXHnJXaE[/yt]

 

[amrcidiot]

How could this possibly lead to an increase in piracy.

I don't know, I was thinking of an audio file being embedded on a website and then transmitting data to the computer that plays it. It would be less noticeable than seeing someone just download a file.
Honestly, I don't really know what I was thinking.
But yeah, the transfer rate isn't fast enough to really do anything on that matter.
Either way though, it's cool to see something like that.

 

[LocutusEstBorg]

Modems used sound cards to transfer data? I never knew that.

Ahh the Winmodem scam. Most hardware modems handled the phone line directly. I.e. They demuxed and extracted the data from the line and sent the data to the computer. When the computer transmitted data, the data was received by the modem and the modem modulated it into the phone line.

The Winmodems on the other hand were nothing but an ordinary sound card which had a telephone jack instead of a 3.5mm stereo jack. The Winmodem literally passed through the incoming sound signal on the phone line to the computer. The Winmodem drivers on the computer would then analyze the audio in realtime and extract the data. Similarily to transmit, the drivers generate the base fax tone frequency and modulate it with the desired data and it would simply playback the audio into the phone line. This hogged the CPU like crazy.

Actually you don't need a modem at all. You can literally connect two computers using the Line In/Out of their soundcards with a 3.5mm stereo cable and transfer data by modulating data into a carrier sound wave and playing it with a media player. Record the output on the other computer and demodulate the data from the carrier wave.

There was actually a company that commercialized this around a decade ago. They sold a phone line to 3.5mm adapter and provided virtual modem drivers that could literally connect to a dialup internet from your sound card.

The Winmodem scam almost repeated itself with DSL. Cheapskate companies tried to con the public with those USB ADSL modems which were nothing but high frequency input sound cards. All the sound analysis and demodulation was done by the drivers.