ios - AVAudioSession中断和路由变化

Question

我正在开发一款包含在后台运行的音频多轨播放器的游戏。在处理暂停所有轨道然后在按下暂停按钮时恢复时，我发现没有太大的困难:

class AudioMultiTrack {

var tracks     : [AudioTrack]
var mixer      : AVAudioMixerNode
var pauseTime  : AVAudioTime?

var engine     = AVAudioEngine()
var volumes    = [Float]()

init(audioTracks: [AudioTrack]){
    tracks = audioTracks
    mixer = engine.mainMixerNode
}

func initialize() {
    for track in tracks {
        track.setUpTrack()
        engine.attach(track.audioPlayer)
        engine.connect(track.audioPlayer, to: mixer, format: track.format)
        track.scheduleFile()
    }

    do {
        try engine.start()
    } catch {
        fatalError("error starting engine")
    }
}

func play() {
    for track in tracks {
        track.audioPlayer.play(at: startTime())
    }
}

func pause() {
    pauseTime = tracks[0].audioPlayer.lastRenderTime

    for track in tracks {
        track.audioPlayer.pause()
    }

}

func unPause() {

    for track in tracks {
        track.scheduleFile()
        track.audioPlayer.play(at: pauseTime)
    }
}

func stop() {
    pauseTime = tracks[0].audioPlayer.lastRenderTime
    engine.stop()

    for track in tracks {
        engine.detach(track.audioPlayer)
    }

    engine.reset()
}

func startTime() ->AVAudioTime {
    let sampleRate = tracks[0].format.sampleRate
    let sampleTime = AVAudioFramePosition(sampleRate)

    return AVAudioTime(sampleTime: sampleTime, atRate: sampleRate)
}

在 GameViewController 中按下暂停键时:

func pausePressed() {
   audio.pause()
}

func continuePressed() {
   audio.unPause()
}

但是，当以这种方式处理中断或路线变更时:

    func handleInterruption(notification: NSNotification) {
    guard let info = notification.userInfo else { return }

    switch info[AVAudioSessionInterruptionTypeKey] as! Int {
    case 0:
        audio.unPause()
    case 1:
        audio.pause()
    default:
        break;
    }
}

程序崩溃，我收到:

*** 由于未捕获的异常“com.apple.coreaudio.avfaudio”而终止应用程序，原因:“所需条件为假:_engine->IsRunning()”

所以看起来音频引擎正在停止，我不想重新初始化音频播放器，原因有很多，包括设置时间和游戏的连续性...

我对问题的评估是否正确？如果是这样，我怎样才能让音频引擎在中断或路由更改时保持运行？

Answer 1

我认为这是不可能的，因为你为每个声音创建了一个音频播放器，它需要准备、设置硬件等。当声音完成后，该设置将被删除并需要重新完成。 IE。保持音频引擎“运行”可能是不可能的。