OSStatus error 1718449215

1718449215 is the decimal representation of the four character code for the kAudioFormatUnsupportedDataFormatError error.

In general you can use something like this to get more information from the errors you receive:

NSError *error = [NSError errorWithDomain:NSOSStatusErrorDomain
                          code:my_error_code
                          userInfo:nil];
NSLog(@"Error: %@", [error description]);