swift - Mac - Swift 3 - 排队音频文件和播放

Question

我想用 swift 3 编写一个应用程序，以便在从一个文件传递到另一个文件时播放排队的音频文件时没有任何间隙、裂缝或噪音。

我的第一次尝试是使用 AvAudioPlayer 和 AvAudioDelegate ( AVAudioPlayer using array to queue audio files - Swift )，但我不知道如何预加载下一首歌曲以避免间隙。即使我知道该怎么做，我也不确定这是实现我目标的最佳方式。 AVQueuePlayer似乎是这份工作的更好候选人，它是为此目的而制作的，但我找不到任何例子来帮助我。也许这只是预加载或缓冲的问题？我有点迷失在这片充满可能性的海洋中。

欢迎任何建议。

Answer 1

它远非完美，特别是如果您想执行两次或更多次(“文件存在”错误)，但它可以作为基础。

它所做的是获取两个文件(我的是 ap. 4 秒的 aif 样本)，将它们编码在一个文件中并播放生成的文件。如果您有数百个，无论是否随机组装，都会非常有趣。

mergeAudioFiles 函数的所有功劳归于@Peyman 和@Pigeon_39。 Concatenate two audio files in Swift and play them

swift 3

import Cocoa
import AVFoundation

var action = AVAudioPlayer()
let path = Bundle.main.path(forResource: "audiofile1.aif", ofType:nil)!
let url = URL(fileURLWithPath: path)
let path2 = Bundle.main.path(forResource: "audiofile2.aif", ofType:nil)!
let url2 = URL(fileURLWithPath: path2)
let array1 = NSMutableArray(array: [url, url2])


class ViewController: NSViewController, AVAudioPlayerDelegate
{

    @IBOutlet weak var LanceStop: NSButton!

    override func viewDidLoad()
    {
        super.viewDidLoad()
    }
    override var representedObject: Any?
    {
        didSet
        {
        // Update the view, if already loaded.
        }
    }

    @IBAction func Lancer(_ sender: NSButton)
    {
      mergeAudioFiles(audioFileUrls: array1)
        let url3 = NSURL(string: "/Users/ADDUSERNAMEHERE/Documents/FinalAudio.m4a")

        do
        {
            action = try AVAudioPlayer(contentsOf: url3 as! URL)
            action.delegate = self
            action.numberOfLoops = 0
            action.prepareToPlay()
            action.volume = 1
            action.play()
        }
        catch{print("error")}

    }


    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool)
    {
        if flag == true
        {

        }
    }

    var mergeAudioURL = NSURL()

    func mergeAudioFiles(audioFileUrls: NSArray) {
        //audioFileUrls.adding(url)
        //audioFileUrls.adding(url2)
        let composition = AVMutableComposition()

        for i in 0 ..< audioFileUrls.count {

            let compositionAudioTrack :AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())

            let asset = AVURLAsset(url: (audioFileUrls[i] as! NSURL) as URL)

            let track = asset.tracks(withMediaType: AVMediaTypeAudio)[0]

            let timeRange = CMTimeRange(start: CMTimeMake(0, 600), duration: track.timeRange.duration)

            try! compositionAudioTrack.insertTimeRange(timeRange, of: track, at: composition.duration)
        }

        let documentDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first! as NSURL
        self.mergeAudioURL = documentDirectoryURL.appendingPathComponent("FinalAudio.m4a")! as URL as NSURL

        let assetExport = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetAppleM4A)
        assetExport?.outputFileType = AVFileTypeAppleM4A
        assetExport?.outputURL = mergeAudioURL as URL
        assetExport?.exportAsynchronously(completionHandler:
            {
                switch assetExport!.status
                {
                case AVAssetExportSessionStatus.failed:
                    print("failed \(assetExport?.error)")
                case AVAssetExportSessionStatus.cancelled:
                    print("cancelled \(assetExport?.error)")
                case AVAssetExportSessionStatus.unknown:
                    print("unknown\(assetExport?.error)")
                case AVAssetExportSessionStatus.waiting:
                    print("waiting\(assetExport?.error)")
                case AVAssetExportSessionStatus.exporting:
                    print("exporting\(assetExport?.error)")
                default:
                    print("Audio Concatenation Complete")
                }
        })
    }
}