我正在尝试构建一个可以从midi文件中渲染音符的序列器。
目前,我正在使用AudioKit进行音乐数据处理。想知道如何使用AudioKit从midi文件中获取音符数据/事件。
我已经尝试使用AKSequencer并输出到AKMIDINode来监听MIDI事件,但似乎无法从中获取任何内容。
class CustomMIDINode: AKMIDINode {
override init(node: AKPolyphonicNode) {
print("Node create") // OK
super.init(node: node)
}
func receivedMIDINoteOff(noteNumber: MIDINoteNumber, velocity: MIDIVelocity, channel: MIDIChannel) {
print("midi note off") // Not printed
}
func receivedMIDISetupChange() {
print("midi setup changed") // Not printed
}
override func receivedMIDINoteOn(_ noteNumber: MIDINoteNumber, velocity: MIDIVelocity, channel: MIDIChannel) {
print("receivedMIDINoteOn") // Not printed
}
}
func setupSynth() {
oscBank.attackDuration = 0.05
oscBank.decayDuration = 0.1
oscBank.sustainLevel = 0.1
oscBank.releaseDuration = 0.1
}
let seq = AKSequencer(filename: "music")
let oscBank = AKOscillatorBank()
var midi = AKMIDI()
let midiNode = CustomMIDINode(node: oscBank)
setupSynth()
midi.openInput()
midi.addListener(midiNode)
seq.tracks.forEach { (track) in
track.setMIDIOutput(midiNode.midiIn)
}
AudioKit.output = midiNode
AudioKit.start()
seq.play()