title: how to determine which codecs a bluetooth device supports over A2DP
body: <p>I have a bluetooth device (headphones) that supports playing audio over A2DP.
  I've been pairing them with both an iPhone and an Android, and I get only extremely poor audio quality with both sources.</p>
  
  <p>My suspicion is that the device only supports the SBC codec, but not Mp3. Or if it does MP3, only an abysmally low bitrate.
  The manufacturer only states A2DP is supported, but not which codecs.</p>
  
  <p>How can I determine which codecs are supported? Is there a kind of protocol sniffer I could use on my phone or my computer and interrogate the device to get a definitive answer on what it supports?</p>