如何使用音频套件保存音频文件?

Question

我有音频文件。我对它做了一些影响

let pitchshifter = AKPitchShifter(self.audioPlayer)
pitchshifter.shift = 10
AudioKit.output = pitchshifter

如果我在应用程序中播放它，它可以工作，但我想将其另存为新文件，以便以后将其用作 avasset。如何实施？

我尝试使用AKNodeRecorder，但这会产生空音轨：

let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("recorded")
let format = AVAudioFormat(commonFormat: .pcmFormatFloat64, sampleRate: 44100, channels: 2, interleaved: false)!
let tape = try! AKAudioFile(forWriting: url, settings: format.settings)
let mixer = AKMixer(self.audioPlayer!, pitchshifter)
AudioKit.output = mixer
self.recorder = try! AKNodeRecorder(node: mixer, file: tape)
try? AudioKit.start()
self.audioPlayer?.play()
self.audioPlayer?.completionHandler = {
self.recorder?.stop()
self.selectedAudioURL = tape.url
}

我也尝试了渲染到文件方法 - 它也不起作用，我得到了这个错误

let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("recorded.m4a")
let format = AVAudioFormat(commonFormat: .pcmFormatFloat64, sampleRate: 44100, channels: 2, interleaved: false)!
let tape = try! AKAudioFile(forWriting: url, settings: format.settings)
try! AudioKit.renderToFile(tape, seconds: Double(CMTimeGetSeconds(self.selectedAudioAsset!.duration)))

这就是我将初始文件添加到 AudioKit 的方式：

let audioFile = try AKAudioFile(forReading: audioURL, commonFormat: .pcmFormatFloat32, interleaved: true)
let player = AKPlayer(audioFile: audioFile)
self.audioFile = audioFile
self.audioPlayer = player
player.startTime = self.startTime
AKSettings.defaultToSpeaker = true

提前感谢您的回答！

Answer 1

根据我的发现，你必须使用预渲染器来"播放"你想要记录的内容：

try AudioKit.renderToFile(outputFileForWriting, duration: sequencerTotalSeconds, prerender: {
self.sequencer.play()
})

但是，对我来说..渲染出单个音轨序列会产生正弦音。:-/

希望这有帮助！