Intercepting Audio Streams & Creating Custom Audio Effects

[rbu...@mail.bradley.edu]

Hi all,

I'm fairly new to NDK, but from what I've seen it appears that NDK (and OpenSL ES) can be used to directly access audio samples and to create your own custom audio effects. What I'm curious about now is if you can intercept audio streams coming from other apps. For instance, I might want to apply my custom filter to what Spotify is currently streaming. Can this be accomplished in Android, or does the existing architecture prevent it? 

[Glenn Kasten]

Android does not currently support what you are requesting.

There is a limited ability to tap into the output mix for visualization,

but not to intercept and modify.

[Patrik Hadorn]

The 'tapping in' part is not supported. Creating custom effects on top of your own audio playback is definitely possible though. OpenSL ES already supports common effects, custom ones can be implemented by processing the audio signal.