file-transfer-over-soundcard

about transfering data between computers using a jury rigged soundcard modem.

Note that these programs are mainly educational, and if you want to do this in a critical situation, you'll at the very least want to add Hamming-code or some other error correction scheme.

The source code consists of a multitude of programs.

• playback and record plays and record a data stream using OSS. If you don't have OSS support, ALSA can emulate it with the 'aoss' wrapper.
• generate turns a binary file into raw wave data.
• generate_psk does the same, except encoding it with phase shift keying.
• analyze turns a recording into data again
• analyze_psk does it for PSK-encoded data.

from  https://github.com/vlofgren/file-transfer-over-soundcard