title: Streaming audio between external bluetooth device and Android phone
body: <p>I'm considering building an Android app that allows for streaming audio via bluetooth to and from the Android phone. I've read similar questions on Stackoverflow before, and based on my understanding, A2DP cannot be used as Android can't become an A2DP sink.</p>
  
  <p>In theory, I believe that a profile such as HFP or HFP AG should allow for bidirectional audio streams. In the Android API, is there a way to force a bluetooth pairing to follow this profile, or does the OS decide which profile to use (such as forcing HFP only when there's a phone call going on)?</p>