在 Swift 中连接两个音频文件并播放它们 [英] Concatenate two audio files in Swift and play them

问题描述

我尝试快速连接 .wav 音频文件.

I try to concatenate .wav audio files in swift.

这是我的代码:

func merge(audio1: NSURL, audio2:  NSURL) {


    var error:NSError?

    var ok1 = false
    var ok2 = false


    var documentsDirectory:String = paths[0] as! String

    //Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack.
    var composition = AVMutableComposition()
    var compositionAudioTrack1:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
    var compositionAudioTrack2:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())

    //create new file to receive data
    var documentDirectoryURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first! as! NSURL
    var fileDestinationUrl = documentDirectoryURL.URLByAppendingPathComponent("resultmerge.wav")
    println(fileDestinationUrl)


    var url1 = audio1
    var url2 = audio2


    var avAsset1 = AVURLAsset(URL: url1, options: nil)
    var avAsset2 = AVURLAsset(URL: url2, options: nil)

    var tracks1 =  avAsset1.tracksWithMediaType(AVMediaTypeAudio)
    var tracks2 =  avAsset2.tracksWithMediaType(AVMediaTypeAudio)

    var assetTrack1:AVAssetTrack = tracks1[0] as! AVAssetTrack
    var assetTrack2:AVAssetTrack = tracks2[0] as! AVAssetTrack


    var duration1: CMTime = assetTrack1.timeRange.duration
    var duration2: CMTime = assetTrack2.timeRange.duration

    var timeRange1 = CMTimeRangeMake(kCMTimeZero, duration1)
    var timeRange2 = CMTimeRangeMake(duration1, duration2)


    ok1 = compositionAudioTrack1.insertTimeRange(timeRange1, ofTrack: assetTrack1, atTime: kCMTimeZero, error: nil)
    if ok1 {

        ok2 = compositionAudioTrack2.insertTimeRange(timeRange2, ofTrack: assetTrack2, atTime: duration1, error: nil)

        if ok2 {
            println("success")
        }
    }

    //AVAssetExportPresetPassthrough => concatenation
    var assetExport = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetPassthrough)
    assetExport.outputFileType = AVFileTypeWAVE
    assetExport.outputURL = fileDestinationUrl
    assetExport.exportAsynchronouslyWithCompletionHandler({
        switch assetExport.status{
        case  AVAssetExportSessionStatus.Failed:
            println("failed (assetExport.error)")
        case AVAssetExportSessionStatus.Cancelled:
            println("cancelled (assetExport.error)")
        default:
            println("complete")
            var audioPlayer = AVAudioPlayer()
            audioPlayer = AVAudioPlayer(contentsOfURL: fileDestinationUrl, error: nil)
            audioPlayer.prepareToPlay()
            audioPlayer.play()
        }

    })

}

并在终端中出现此错误(在 iPhone 上运行):

And get this error in the terminal (running on a iPhone) :

file:///var/mobile/Containers/Data/Application/3F49D360-B363-4600-B3BB-EE0810501910/Documents/resultmerge.wav

成功

failed Error Domain=AVFoundationErrorDomain Code=-11838 "Opération interrompue" UserInfo=0x174269ac0 {NSLocalizedDescription=Opération interrompue, NSLocalizedFailureReason=L'opération n'est pas Prize en charge pour ce contenu.}

但我不知道为什么会出现此错误.如果您能给我任何帮助，我将不胜感激:)

But I don't know why I'm getting this error. I would greatly appreciate any help you can give me :)

推荐答案

我通过更改两件事让您的代码正常工作:

I got your code working by changing two things:

• 预设名称:从AVAssetExportPresetPassthrough到AVAssetExportPresetAppleM4A

输出文件类型:从AVFileTypeWAVE到AVFileTypeAppleM4A

像这样修改你的 assetExport 声明:

Modify your assetExport declaration like this:

var assetExport = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetAppleM4A)
assetExport.outputFileType = AVFileTypeAppleM4A

然后它将正确合并文件.

then it will properly merge the files.

看起来 AVAssetExportSession 只导出 M4A 格式而忽略其他预设.可能有一种方法可以让它导出其他格式(通过子类化它?)，尽管我还没有探索这种可能性.

It looks like AVAssetExportSession only exports M4A format and ignores other presets. There may be a way to make it export other formats (by subclassing it?), though I haven't explored this possibility yet.

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