Lighthouse case of (forgotten) prior art.
AudioTransmit – Transmitting data between computers using audio
11–20 of 32 posts
Re: AudioTransmit – Transmitting data between computers using audio
#12Are there any audio data transmission protocols that use the full spectrum of sound a microphone and speaker can typically produce instead of just those frequencies that work on a POTS line?
Re: AudioTransmit – Transmitting data between computers using audio
#13Fun project, but if you google a bit, you'll find a lot of these. Even on HN, ie. https://news.ycombinator.com/item?id=17333257
Re: AudioTransmit – Transmitting data between computers using audio
#14This will alternate between two different tones, one representing 0 and another representing one, each bit lasting 50 ms, giving a bitrate of 20 bits/s. This is obviously rather slow, so more a fun weekend experiment than a practical tool. There is a really deep rabbit hole when it comes to doing this more efficiently, getting into signal processing, modulation, encoding, error correction and more. And of cause, thin…
yes it's a rabbit hole, I know it well! When PC became fast enough to be used as DSP engines with the soundcard I spent years playing with the creation of "digital modes" as HAM radio hobbyist.
Re: AudioTransmit – Transmitting data between computers using audio
#15Wheel successfully reinvented :)
Nothing stopping you setting up a whole AX.25 network between multiple machines using Dire Wolf [1] and the built-in AX.25 [2] (a derivation of X.25) support still in the Linux kernel. You get a proper network interface that shows up alongside eth0. Nice short instructions at [3]. Just don't hook it up to radios unless you're appropriately licensed. Speakers and mics only.
[1] https://github.com/wb2osz/direwolf
Re: AudioTransmit – Transmitting data between computers using audio
#16Cool idea. I could imagine a version of this being used by whistleblower to get data out of a company. Maybe a web version and they could capture the data with a voice recording app.
Re: AudioTransmit – Transmitting data between computers using audio
#17There are some projects which try to make the audio sound pleasant, like birdsong or water. And there are fountain codes which continually stream data and you can start picking up the transmission at any point and as long as you get enough of it you can recreate the message. And of course compared to wifi you don't need to 'join' a network or broadcast anything to listen.
I'm imagining something like this at a train station or airport, continually broadcasting schedule and delay information which you could pick up with an app and a microphone and no internet access. Like a drinking fountain for information something you go to, or maybe pervasive background noise.
Re: AudioTransmit – Transmitting data between computers using audio
#18IIRC, some viruses use inaudible frequencies to transfer data when data transport over a a classical network is unavailable.
Re: AudioTransmit – Transmitting data between computers using audio
#19... I mean, this is very cool and definitely good work, but I'm pretty sure I remember transmitting data via audio quite a lot back in the day, and it sounded like BEEEEEEEEPBOOPCRRRSSSHHHWRRRRTTSSSFFFTHHHHH. (Ironically, I often then used the audio-to-data connection to download audio that had also been converted to data. I think I still have those old MP3s of Orbital's set at Glastonbury 1995 somewhere.) :-D
https://www.youtube.com/watch?v=gsNaR6FRuO0
Comedic animated version: https://www.youtube.com/watch?v=dTos3CsvnLQ
Re: AudioTransmit – Transmitting data between computers using audio
#20But does it sound like a duck choking on a kazoo? (old acoustic modem joke sorry)