The Dual-tone multi-frequency signaling Android decoder.
The aplication recognise tones it steps:
- capture sound from the microfone,
- transforme it using Fast Fourier Transform (thanks to http://introcs.cs.princeton.edu/java/97data/FFT.java.html),
- do additional clean-up to reduce noices,
- find picks on the frequency spectrum,
- put the reconised number into the text field.
TProject source http://code.google.com/p/dtmf-decoder.
Code license: GNU Lesser GPL.
It was created for Android 2.2.3 (Froyo) Imported into android studio and tested successfully on android 6.
The project is no longer maintained.