objective-c - 録音したピッチを変更しようとしていますが、readBytesResult でエラーが発生します

Question

http://devnulldb.blogspot.in/2012/07/how-to-set-up-openal-and-play-sound.htmlの例を参照しています

誰でも私を助けてくれませんか

UInt32 bytesRead = (UInt32)fileSizeInBytes;
void* audioData = malloc(bytesRead);



OSStatus readBytesResult = AudioFileReadBytes(afid, false, 0, &bytesRead, audioData);

// "here I'm getting the value of readBytesResult -39"

if (0 != readBytesResult) {
    NSLog(@"An error occurred when attempting to read data from audio file %@: %ld", _url, readBytesResult);
}