public static extern int FLAC__stream_decoder_init_file(IntPtr context, string filename, Decoder_WriteCallback write, Decoder_MetadataCallback metadata, Decoder_ErrorCallback error, IntPtr userData);
public static extern StreamDecoderInitStatus FLAC__stream_decoder_init_stream( IntPtr context, Decoder_StreamDecoderReadCallback readCallback, Decoder_StreamDecoderSeekCallback seekCallback, Decoder_StreamDecoderTellCallback tellCallback, Decoder_StreamDecoderLengthCallback lengthCallback, Decoder_StreamDecoderEofCallback eofCallback, Decoder_WriteCallback writeCallback, Decoder_MetadataCallback metadataCallback, Decoder_ErrorCallback errorCallback);