05-10-2014 11:05 AM
I want to analyse audio in real time with FFT (Fast Fourier Transformation) to get the frequency of the audio input of the device. I was searching for a way to retrieve the raw audio stream or something like that but the only classes I found was the AudioManager. I guess I have to use low level C functions for this instead of the higher level manager because that class can only save the audio to a file. I want to analyse the sound in real time instead of recording, analysing it and then showing the results.
Thanks in advance!
05-10-2014 11:33 AM
05-12-2014 01:54 AM
Thanks for the link. I will probably use a 3rd party library for the FFT.
Any ideas on how to analyse the sound? I mean, should I capture a lot of short sound samples from the microphone and analyse those with FFT or is it possible to analyse it in real time? I want to retrieve the frequency of the input signal.
05-12-2014 08:55 AM
05-15-2014 06:35 AM
This may be perhaps be of some interest in this context:
When I was looking at attaching accessories to BlackBerry 10 devices I took a look at using the Audio Jack as a transport medium. It implements a simple audio FSK ( Frequency Shift Keying ) scheme to allow encoding of character data. The part that's probably common with your requirements is how I manipulated blocks of audio PCM samples.
Anyway, the code is here:
And there is even a video of it working here courtesy of my collegue @mdwrim
In practical terms the real challenge using the audio port in a breadboard scenario was noise.
Anyway, it was a fun project and demonstrated a number of patterns in manipulating audio.