Audio File Stream Services

AudioFileStreamOpen

OSStatus  AudioFileStreamOpen (
   void                                  *inClientData,
   AudioFileStream_PropertyListenerProc  inPropertyListenerProc,
   AudioFileStream_PacketsProc           inPacketsProc,
   AudioFileTypeID                       inFileTypeHint,
   AudioFileStreamID                     *outAudioFileStream
);

回调函数inPropertyListenerProc，和inPacketsProc

inPropertyListenerProc用于监听property可获得，可以使用AudioFileStreamGetPropertyInfo and AudioFileStreamGetProperty得到相应的property的value。

inPacketsProc您的音频数据的回调。当解析器发现数据流中的音频数据包，它传递数据到您的音频数据的回调。
Audio File Stream Properties
Audio file stream properties contain information that you can use to help interpret the audio data in a stream.
enum {
   kAudioFileStreamProperty_ReadyToProducePackets    = 'redy',
   kAudioFileStreamProperty_FileFormat               = 'ffmt',
   kAudioFileStreamProperty_DataFormat               = 'dfmt',
   kAudioFileStreamProperty_FormatList               = 'flst',
   kAudioFileStreamProperty_MagicCookieData          = 'mgic',
   kAudioFileStreamProperty_AudioDataByteCount       = 'bcnt',
   kAudioFileStreamProperty_AudioDataPacketCount     = 'pcnt',
   kAudioFileStreamProperty_MaximumPacketSize        = 'psze',
   kAudioFileStreamProperty_DataOffset               = 'doff',
   kAudioFileStreamProperty_ChannelLayout            = 'cmap',
   kAudioFileStreamProperty_PacketToFrame            = 'pkfr',
   kAudioFileStreamProperty_FrameToPacket            = 'frpk',
   kAudioFileStreamProperty_PacketToByte             = 'pkby',
   kAudioFileStreamProperty_ByteToPacket             = 'bypk',
   kAudioFileStreamProperty_PacketTableInfo          = 'pnfo',
   kAudioFileStreamProperty_PacketSizeUpperBound     = 'pkub',
   kAudioFileStreamProperty_AverageBytesPerPacket    = 'abpp',
   kAudioFileStreamProperty_BitRate                  = 'brat'
};