我正在开发一个应用程序，让用户可以通过应用程序录制和修改他们的声音并分享。基本上，我已经完成了很多工作，现在是向您求助的时候了。这是我的播放功能，在播放录制的音频文件时添加音效。
private func playAudio(pitch : Float, rate: Float, reverb: Float, echo: Float) {
// Initialize variables
audioEngine = AVAudioEngine()
audioPlayerNode = AVAudioPlayerNode()
audioEngine.attachNode(audioPlayerNode)
// Setting the pitch
let pitchEffect = AVAudioUnitTimePitch()
pitchEffect.pitch = pitch
audioEngine.attachNode(pitchEffect)
// Setting the platback-rate
let playbackRateEffect = AVAudioUnitVarispeed()
playbackRateEffect.rate = rate
audioEngine.attachNode(playbackRateEffect)
// Setting the reverb effect
let reverbEffect = AVAudioUnitReverb()
reverbEffect.loadFactoryPreset(AVAudioUnitReverbPreset.Cathedral)
reverbEffect.wetDryMix = reverb
audioEngine.attachNode(reverbEffect)
// Setting the echo effect on a specific interval
let echoEffect = AVAudioUnitDelay()
echoEffect.delayTime = NSTimeInterval(echo)
audioEngine.attachNode(echoEffect)
// Chain all these up, ending with the output
audioEngine.connect(audioPlayerNode, to: playbackRateEffect, format: nil)
audioEngine.connect(playbackRateEffect, to: pitchEffect, format: nil)
audioEngine.connect(pitchEffect, to: reverbEffect, format: nil)
audioEngine.connect(reverbEffect, to: echoEffect, format: nil)
audioEngine.connect(echoEffect, to: audioEngine.outputNode, format: nil)
audioPlayerNode.stop()
let length = 4000
let buffer = AVAudioPCMBuffer(PCMFormat: audioPlayerNode.outputFormatForBus(0),frameCapacity:AVAudioFrameCount(length))
buffer.frameLength = AVAudioFrameCount(length)
try! audioEngine.start()
let dirPaths: AnyObject = NSSearchPathForDirectoriesInDomains( NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)[0]
let tmpFileUrl: NSURL = NSURL.fileURLWithPath(dirPaths.stringByAppendingPathComponent("effectedSound.m4a"))
do{
print(dirPaths)
let settings = [AVFormatIDKey: NSNumber(unsignedInt: kAudioFormatMPEG4AAC), AVSampleRateKey: NSNumber(integer: 44100), AVNumberOfChannelsKey: NSNumber(integer: 2)]
self.newAudio = try AVAudioFile(forWriting: tmpFileUrl, settings: settings)
audioEngine.outputNode.installTapOnBus(0, bufferSize: (AVAudioFrameCount(self.player!.duration)), format: self.audioPlayerNode.outputFormatForBus(0)){
(buffer: AVAudioPCMBuffer!, time: AVAudioTime!) in
print(self.newAudio.length)
print("=====================")
print(self.audioFile.length)
print("**************************")
if (self.newAudio.length) < (self.audioFile.length){
do{
//print(buffer)
try self.newAudio.writeFromBuffer(buffer)
}catch _{
print("Problem Writing Buffer")
}
}else{
self.audioPlayerNode.removeTapOnBus(0)
}
}
}catch _{
print("Problem")
}
audioPlayerNode.play()
}
我猜问题出在我给audioPlayerNode安装了installTapOnBus，但是影响音频的是audioEngine.outputNode。然而，我尝试给audioEngine.outputNode安装installTapOnBus，但是出现了错误。我也尝试将效果连接到audioEngine.mixerNode，但这也不是一个解决方案。那么你有没有保存受影响的音频文件的经验？我该如何获取这个受影响的音频呢？
非常感谢您的帮助。