AudioKit-使用定序器在特定位置播放声音文件

Question

enum Sequence: Int {
    case snareDrum
}
var snareDrum = AKSynthSnare()
var sequencer = AKSequencer()
var pumper: AKCompressor?
var mixer = AKMixer()

public init() {
    snareDrum >>> mixer
    pumper = AKCompressor(mixer)

    AudioKit.output = pumper
    AudioKit.start()
}

func setupTracks() {
    _ = sequencer.newTrack()
    sequencer.tracks[Sequence.snareDrum.rawValue].setMIDIOutput(snareDrum.midiIn)
    generateMessageSequence()

    sequencer.enableLooping()
    sequencer.setTempo(2000)
    sequencer.play()
}    

for i in message {
  counter+=0.15
  if (i=="1") {
   // play high sound at specific position 
  }
  else {
   // play low sound at specific position
  } 
}

(o)在特定位置播放低音：

 sequencer.tracks[Sequence.snareDrum.rawValue].add(noteNumber: 20,
                                                   velocity: 10,
                                                   position: AKDuration(beats: counter),
                                                   duration: AKDuration(beats: 1))

我的问题是：如何能够使用(Position:AKDuration（Beats：counter））//上面的代码而不是使用默认的工具（如本例中的AKSynthSnare()）在特定位置播放本地声音文件？

Answer 1

您可以创建两个曲目，每个曲目使用AKMIDispampler。一个播放“低”样本，另一个播放“高”样本。把高音分配给高音轨，低音分配给低音轨。

let sequencer = AKSequencer()
let lowTrack = sequencer.newTrack()
let lowSampler = AKMIDISampler()
try! lowSampler.loadWav("myLowSoundFile")
lowTrack?.setMIDIOutput(lowSampler.midiIn)

let highTrack = sequencer.newTrack()
let highSampler = AKMIDISampler()
try! highSampler.loadWav("myHighSoundFile")
highTrack?.setMIDIOutput(highSampler.midiIn)

sequencer.setLength(AKDuration(beats: 4.0))
sequencer.enableLooping()

然后将高、低音分配给每首曲目

let message = "1100011010"
let dur = 4.0 / Double(message.count)
var position: Double = 0
for i in message {
  position += dur

  if (i == "1") {
   highTrack?.add(noteNumber: 60, velocity: 100, position: AKDuration(beats: position), duration: AKDuration(beats: dur * (2/3)))
  } else {
   lowTrack?.add(noteNumber: 60, velocity: 100, position: AKDuration(beats: position), duration: AKDuration(beats: dur * (2/34)))
  } 
}

（我还没有运行代码，但类似这样的东西应该可以工作）