Thanks for your reply, bocanegra. Eventually, I found out Android allowed me to use a samplerate of 8000Hz and that was low enough to allow me to create a wideband spectrogram (125Hz per band). Thanks to everyone for your replies.

Apparently, it cannot be done, since you can neither force the sampling frequency to be low enough nor the blocksize to be high enough to get a narrow-band spectrogram.

Now it's working, I had forgotten to include bangs onResume and onPause.

In my code, you do have that time difference and and in fact it "sometimes" does read the array. That's the crazy part; sometimes it works and sometimes it gives me a steady (though other than 0) value instead.

I know this is old, but have you found a solution; because I'm having the same problem.

Sorry, yes, I'm using libpd. I'm trying to create a wide-band spectrogram app for Android.

Is it possible to send the values obtained from rfft to an app file? Sorry if it's a silly question, but I can't seem to find the answer anywhere.

I'm trying to create a wideband specrogram app for Android, but I don't seem to get the right set-up for the patch. Everything I get from the rfft object looks narrowband at first sight (seen in a PD canvas).
PS: I'm just a language teacher so I'm way beyond my dephth here, but I have managed to do it with javascript in the past.

Me again. After digging for a while in android forums, I still cannot get echo cancellation to work. I keep getting "Attempt to invoke virtual method 'int android.media.audiofx.AcousticEchoCanceler.setEnabled(boolean)' on a null object reference".

Thank you very much. The problem was (as you correctly guessed) the soundcard mic settings. Now I have to take the time to explore this in Android.

Thanks again.