ios - 音频播放有问题

Question

项目架构布局:

录制音频 -> 修剪音频 -> 播放修剪后的音频 -> 上传到服务器。

我在播放因 AVAssetExportSession 修剪而创建的音频文件时遇到问题。我怀疑修剪文件的完整性，我已将其上传到服务器并在那里播放正常，但 iOS 拒绝播放。我用修剪文件的 URL 初始化 AVAudioPlayer，然后 play() 没有任何反应，甚至没有抛出错误。

请看下面的代码，是什么导致了这个问题？

  static func outputFileURL() -> URL {

    let outputFileURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.path.appending("/audioRecord-trimmed.m4a")
    return URL(fileURLWithPath: outputFileURL)

  }


@IBAction func trimRecording(_ sender: RoundCornerButton) {

    //Delete existing recording
    deleteEditedRecording()

    //Check duration
    let duration = CMTimeGetSeconds(recordingToTrim.duration)

    if (duration < 5.0) {

      let alertController = UIAlertController(title: "Warning", message: "Sound is too short", preferredStyle: UIAlertControllerStyle.alert)

      let action = UIAlertAction(title: "OK", style: UIAlertActionStyle.cancel, handler: nil)

      alertController.addAction(action)

      self.present(alertController, animated: true, completion: nil)

      return

    } else {

      let exporter = AVAssetExportSession(asset: recordingToTrim, presetName: AVAssetExportPresetAppleM4A)

      exporter?.outputFileType = AVFileTypeAppleM4A

      exporter?.outputURL = EditorVC.outputFileURL()

      exporter?.timeRange = durationToTrim!

      exporter?.exportAsynchronously(completionHandler: {

        if exporter?.status == .completed {

          let alertController = UIAlertController(title: "Success", message: nil, preferredStyle: UIAlertControllerStyle.alert)

          let action = UIAlertAction(title: "OK", style: UIAlertActionStyle.cancel, handler: nil)

          alertController.addAction(action)

          self.present(alertController, animated: true, completion: nil)

        } else {

          let alertController = UIAlertController(title: "Error", message: exporter?.error?.localizedDescription, preferredStyle: UIAlertControllerStyle.alert)

          let action = UIAlertAction(title: "OK", style: UIAlertActionStyle.cancel, handler: nil)

          alertController.addAction(action)

          self.present(alertController, animated: true, completion: nil)

          print(exporter?.error?.localizedDescription)

          print("Export failed")

          return
        }

      })
    }

  }

@IBAction func playTrimmedAudio(_ sender: RoundCornerButton) {

    print("\nPlay tap\n")

    let player = try! AVAudioPlayer(contentsOf: EditorVC.outputFileURL())
    player.play()
 }

Answer 1

像这样全局声明音频播放器:

var player:AVAudioPlayer!

在你的 playTrimmedAudio 函数中添加这两行代码

player = try! AVAudioPlayer(contentsOf: EditorVC.outputFileURL())
player.play()