我正在使用基于此的代码在Swift 中将mp3转换为m4a。
当我生成PCM文件时,它可以工作。当我将导出格式更改为m4a时,它将生成一个文件,但无法播放。为什么会腐败?
这是到目前为止的代码:
import AVFoundation
import UIKit
class ViewController: UIViewController {
    var rwAudioSerializationQueue:dispatch_queue_t!
    var asset:AVAsset!
    var assetReader:AVAssetReader!
    var assetReaderAudioOutput:AVAssetReaderTrackOutput!
    var assetWriter:AVAssetWriter!
    var assetWriterAudioInput:AVAssetWriterInput!
    var outputURL:NSURL!
    override func viewDidLoad() {
        super.viewDidLoad()
        let rwAudioSerializationQueueDescription = String(self) + " rw audio serialization queue"
        // Create the serialization queue to use for reading and writing the audio data.
        self.rwAudioSerializationQueue = dispatch_queue_create(rwAudioSerializationQueueDescription, nil)
        let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
        let documentsPath = paths[0]
        print(NSBundle.mainBundle().pathForResource("input", ofType: "mp3"))
        self.asset = …