AVAudioPlayer returns error "pty?"

AVAudioPlayer seems not to handle some audio files that can be handled开发者_JAVA技巧 if using AudioStreamer (https://github.com/mattgallagher/AudioStreamer) even when played as a local file.

My questions:

1) What type of audio files generate the error code "pty?". NOTE: Audio file plays fine in QuickTime Player.

2) The following code generates the same error using this audio file:

UInt32 size;
OSStatus err = AudioFileGetPropertyInfo([self audioFileID], kAudioFilePropertyChannelLayout, &size, NULL);

But using the stream api on the same audio file this will work (ok different properties are fetched but then the question is why can't channel layout be asked?):

err = AudioFileStreamGetPropertyInfo(inAudioFileStream, kAudioFileStreamProperty_FormatList, &formatListSize, &outWriteable);

I know that if you stream audio you need to use the stream api because only a part of the file is available at the time. But when the complete file is in the filesystem the file audio api should be possible to use (?)

3) Is it recommended to use stream api even if the file is local? Good ideas how to implement it are welcome.

What puzzles me is why AudioFile* api fails were AudioFileStream* works.