Detect DTMF Tones C#

Question

I have wav file in which using the naudio lib i have been able to get raw data out of the wav files.

Does any one know how to loop though the data in chuncks detecting DTMF tones?

Answer 1

I've gone with http://www.tapiex.com/ToneDecoder.Net.htm

Its cheeap and does a good job at detection. All the others i found dont seem to do the job or have no documentation

Answer 2

The NuGet package DtmfDetection.NAudio provides extension methods and wrappers to detect DTMF tones in live (captured) audio and pre-recorded audio files.

On the GitHub site of the project you can find a sample program.

Answer 3

Well, on the top of the google is this:

http://sourceforge.net/projects/dtmf-cs/

But, if you want to use heavy artillery, you can always FFT your samples and check what two freqs are seen the most.

BTW, do some searching before you post anything, and you'll come up with:

Detect a specific frequency/tone from raw wave-data

or even

Is it possible to detect DTMF tones using C#

Answer 4

DTMF stands for dual-tone multi frequence signaling. So you have to detect the two frequencies used to send a signal.

You have to transform your timebased audio material into the frequency domain typically by using a FFT algorithm.

Here i found a very old VB5 program with source online which does exactly what you want i think: http://www.qsl.net/kb5ryo/dtmf.htm

EDIT: Ok, maybe its better to take a look at the suggested C# lib.