Objective C - Recording Audio Stream - objective-c

Question

I'm looking for a solution to record an audio stream to a file. I can get audio to play but I'm struggling to figure out how to record/save to file what is playing.
A nudge in the right direction would be greatly appreciated.
Player code thus far:
#interface ViewControllerPlayer ()
#end
#implementation ViewControllerPlayer
#synthesize receivedStreamReferenceNumber;
- (void)convertData:(NSData *) data {
NSString *urlString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSURL *url = [[NSURL alloc] initWithString:urlString];
[self loadPlayer:url];
}
- (void) loadPlayer:(NSURL *) url {
audioPlayer = [AVPlayer playerWithURL:url];
[audioPlayer play];
}
- (void) start {
NSLog(#"%#", receivedStreamReferenceNumber);
NSString *urlHalf = #"http://getstreamurl.php?KeyRef=";
NSMutableString *mutableUrlString = [NSMutableString stringWithFormat:#"%#%#", urlHalf, receivedStreamReferenceNumber];
NSURL *url = [NSURL URLWithString: mutableUrlString];
NSData *data = [NSData dataWithContentsOfURL:url];
[self convertData:data];
}
- (void)viewDidLoad {
[super viewDidLoad];
[self start];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
EDIT:
I've incorporated the following code... but i'm struggling to tie it all together. The following should create a file that the recorded stream audio is saved to. I suppose i've got to tell the AVRecorder to listen to the AVPlayer some how? Again -- help will be greatly appreciated:
- (void)viewDidLoad
{
[super viewDidLoad];
[stopButton setEnabled:YES];
[playButton setEnabled:YES];
// Set the audio file
NSArray *pathComponents = [NSArray arrayWithObjects:
[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject],
#"xxx.mp3",
nil];
NSURL *outputFileURL = [NSURL fileURLWithPathComponents:pathComponents];
// Setup audio session
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
NSMutableDictionary *recordSetting = [[NSMutableDictionary alloc] init];
[recordSetting setValue:[NSNumber numberWithInt:kAudioFormatMPEG4AAC] forKey:AVFormatIDKey];
[recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];
[recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];
recorder = [[AVAudioRecorder alloc] initWithURL:outputFileURL settings:recordSetting error:nil];
recorder.delegate = self;
recorder.meteringEnabled = YES;
[recorder prepareToRecord];
}