title: iOS Audio Streaming only works for **SOME** bluetooth devices?
body: <p>I am working on iOS app which will be compatible with iOS 6/7 and stream audio .mp3 files from a website.</p>
  
  <p>I have <em>already</em> gotten this to work using the following code:</p>
  
  <pre><code>-(NSString*)documentsFolder
  {
      NSString* dataPath =  [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
      if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
          [[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:NULL];
      return dataPath;
  }
  
  -(NSString*)createURLFile:(NSString*)songURL
  {
     NSString* M3U_FILE = @"song.m3u";
     NSString* path = [NSString stringWithFormat:@"%@",[[self documentsFolder] stringByAppendingPathComponent:M3U_FILE]];
      if([[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil])
      {
        NSFileHandle* outFile = [NSFileHandle fileHandleForWritingAtPath:path];
          if(outFile != nil)
        {
           NSData* buffer = [songURL dataUsingEncoding:NSUTF8StringEncoding];
           [outFile writeData:buffer];
           return path;
        }
     }
      return nil;
  }
  
  
  - (void)createStreamer
  {
      // Remove any previous references.
      [[NSNotificationCenter defaultCenter] removeObserver:self];
      // Create a new player.
      NSString* fileURL = [self createURLFile:self.aSong.songpath];
      self.songPlayer = [[AVPlayer alloc]initWithURL:[NSURL fileURLWithPath:fileURL]];
      NSAssert(self.songPlayer != nil, @"NIL AVPlayer Created!!!");
      // Observer for when the song ends...
      [[NSNotificationCenter defaultCenter] addObserver:self
                                               selector:@selector(playerItemDidReachEnd:)
                                                   name:AVPlayerItemDidPlayToEndTimeNotification
                                                 object:[self.songPlayer currentItem]];
      [[UIApplication sharedApplication] setIdleTimerDisabled: YES];
  }
  </code></pre>
  
  <p>I store the url for the .mp3 file in a local .m3u file and use that to load up the AVPlayer.  In earlier versions of iOS, I was told that the AVPlayer would load the song first and then play it, not stream it immediately.  While this does not appear to be true in iOS 6/7 (the song starts streaming almost immediately), the .m3u file was being created in case there were any problems created by <em>not</em> having it done this way.</p>
  
  <p>With this, a loop is monitoring the status of the AVPlayer and after a few seconds, the audio starts to play out the phone without a problem.  </p>
  
  <p>For testing purposes, I set up an MPVolumeView on the page which plays songs:</p>
  
  <pre><code>MPVolumeView *volumeView = [[[MPVolumeView alloc] initWithFrame:CGRectMake(0, 0, 310, 20)] autorelease];
  volumeView.center = CGPointMake(160,62);
  [volumeView sizeToFit];
  [self.view addSubview:volumeView];
  </code></pre>
  
  <p>The reason for this is that the volume slider will also show an indicator if the bluetooth is connected as an audio output source and allow me to change the audio route between the phone and the bluetooth device.  So far, so good.</p>
  
  <p><em><strong>I connected my phone to my Jawbox Jambone via bluetooth, start the AVPlayer on a song, and the song comes out of the Jawbox as expected.  The volume control has the small "rectangle with arrow" indicating that I can switch the audio output and indeed, while the song is playing, I can switch between the phone and the Jawbox.</em></strong>  Happiness.</p>
  
  <p>The problem occurs when I try to connect it to a car.  I have two experiences with this:</p>
  
  <ol>
  <li>The car is already paired with the phone for making/receiving calls.  The phone even indicates it is paired when I get into the car.  But when I use the same code to play the same audio files, they only come out of the phone.  The volume slider does not show the "bluetooth route" indicator at all (like it does not recognize the car as a audio output route).</li>
  <li>In another car, the audio was streaming from another app (some radio streaming app).  The other app was stopped and this one started.  The audio started playing for the same song tested above, but stopped after a second or two.  Again, there was no indicator on the volume slider that the bluetooth was connected at this point.</li>
  </ol>
  
  <p>Can somebody explain to me why the audio could stream fine out to one bluetooth device but not to another?</p>
  
  <p>Have I missed something (an entitlement?) in the profile for my app that will allow it to stream audio via bluetooth to a car?</p>