I've made an app in Android Studio which is essentially a parametric EQ with some additional features. The app takes signal from the microphone source (whether the built-in mic or external mic). The signal is then passed through biquad filters and out to the speakers/earphones. I used LibPb to handle the signal processing.
Now, I want all the audio that would be coming out the speakers to be routed through the app. In other words, any music playing or calls, I want the audio to also be passed through the filters in my app.
I have tried to find articles/resources on this topic but haven't found much. I'm guessing that it can be done via Audio Focus or Media Router or something along those lines, but I cant figure it out!!
Firstly, is this possible?
Secondly, any code or hints as to how to go about it?
Any help is much appreciated!!