如何让 AKSequencer 切换音色？
How to make the AKSequencer switch soundfonts?
我正在使用 Audiokit API 创建一个函数，用户将音符按到屏幕上，然后根据他们选择的 SoundFont 发出声音。然后我让他们收集大量笔记，让他们按照他们选择的顺序播放。
问题是我正在使用 AKSequencer 来回放音符，而当 AKSequencer 回放音符时，它听起来不像 SoundFont。它发出哔声。
是否有代码可以让我更改 AKSequencer 发出的声音？
我正在使用音频套件来执行此操作。
示例是一个 NSObject，其中包含 midisampler、播放器等。这是代码
class Sampler1: NSObject {
var engine = AVAudioEngine()
var sampler: AVAudioUnitSampler!
var midisampler = AKMIDISampler()
var octave = 4
let midiChannel = 0
var midiVelocity = UInt8(127)
var audioGraph: AUGraph?
var musicPlayer: MusicPlayer?
var patch = UInt32(0)
var synthUnit: AudioUnit?
var synthNode = AUNode()
var outputNode = AUNode()
override init() {
super.init()
// engine = AVAudioEngine()
sampler = AVAudioUnitSampler()
engine.attach(sampler)
engine.connect(sampler, to: engine.mainMixerNode, format: nil)
loadSF2PresetIntoSampler(5)
/* sampler2 = AVAudioUnitSampler()
engine.attachNode(sampler2)
engine.connect(sampler2, to: engine.mainMixerNode, format: nil)
*/
addObservers()
startEngine()
setSessionPlayback()
/* CheckError(NewAUGraph(&audioGraph))
createOutputNode(audioGraph: audioGraph!, outputNode: &outputNode)
createSynthNode()
CheckError(AUGraphNodeInfo(audioGraph!, synthNode, nil, &synthUnit))
let synthOutputElement: AudioUnitElement = 0
let ioUnitInputElement: AudioUnitElement = 0
CheckError(AUGraphConnectNodeInput(audioGraph!, synthNode, synthOutputElement,
outputNode, ioUnitInputElement))
CheckError(AUGraphInitialize(audioGraph!))
CheckError(AUGraphStart(audioGraph!))
loadnewSoundFont()
loadPatch(patchNo: 0)*/
setUpSequencer()
}
func createOutputNode(audioGraph: AUGraph, outputNode: UnsafeMutablePointer<AUNode>) {
var cd = AudioComponentDescription(
componentType: OSType(kAudioUnitType_Output),
componentSubType: OSType(kAudioUnitSubType_RemoteIO),
componentManufacturer: OSType(kAudioUnitManufacturer_Apple),
componentFlags: 0,componentFlagsMask: 0)
CheckError(AUGraphAddNode(audioGraph, &cd, outputNode))
}
func loadSF2PresetIntoSampler(_ preset: UInt8) {
guard let bankURL = Bundle.main.url(forResource: "Arachno SoundFont - Version 1.0", withExtension: "sf2") else {
print("could not load sound font")
return
}
let folder = bankURL.path
do {
try self.sampler.loadSoundBankInstrument(at: bankURL,
program: preset,
bankMSB: UInt8(kAUSampler_DefaultMelodicBankMSB),
bankLSB: UInt8(kAUSampler_DefaultBankLSB))
try midisampler.loadSoundFont(folder, preset: 0, bank: kAUSampler_DefaultBankLSB)
// try midisampler.loadPath(bankURL.absoluteString)
} catch {
print("error loading sound bank instrument")
}
}
func createSynthNode() {
var cd = AudioComponentDescription(
componentType: OSType(kAudioUnitType_MusicDevice),
componentSubType: OSType(kAudioUnitSubType_MIDISynth),
componentManufacturer: OSType(kAudioUnitManufacturer_Apple),
componentFlags: 0,componentFlagsMask: 0)
CheckError(AUGraphAddNode(audioGraph!, &cd, &synthNode))
}
func setSessionPlayback() {
let audioSession = AVAudioSession.sharedInstance()
do {
try
audioSession.setCategory(AVAudioSession.Category.playback, options:
AVAudioSession.CategoryOptions.mixWithOthers)
} catch {
print("couldn't set category \(error)")
return
}
do {
try audioSession.setActive(true)
} catch {
print("couldn't set category active \(error)")
return
}
}
func startEngine() {
if engine.isRunning {
print("audio engine already started")
return
}
do {
try engine.start()
print("audio engine started")
} catch {
print("oops \(error)")
print("could not start audio engine")
}
}
func addObservers() {
NotificationCenter.default.addObserver(self,
selector:"engineConfigurationChange:",
name:NSNotification.Name.AVAudioEngineConfigurationChange,
object:engine)
NotificationCenter.default.addObserver(self,
selector:"sessionInterrupted:",
name:AVAudioSession.interruptionNotification,
object:engine)
NotificationCenter.default.addObserver(self,
selector:"sessionRouteChange:",
name:AVAudioSession.routeChangeNotification,
object:engine)
}
func removeObservers() {
NotificationCenter.default.removeObserver(self,
name: NSNotification.Name.AVAudioEngineConfigurationChange,
object: nil)
NotificationCenter.default.removeObserver(self,
name: AVAudioSession.interruptionNotification,
object: nil)
NotificationCenter.default.removeObserver(self,
name: AVAudioSession.routeChangeNotification,
object: nil)
}
private func setUpSequencer() {
// set the sequencer voice to storedPatch so we can play along with it using patch
var status = NewMusicSequence(&musicSequence)
if status != noErr {
print("\(#line) bad status \(status) creating sequence")
}
status = MusicSequenceNewTrack(musicSequence!, &track)
if status != noErr {
print("error creating track \(status)")
}
// 0xB0 = bank select, first we do the most significant byte
var chanmess = MIDIChannelMessage(status: 0xB0 | sequencerMidiChannel, data1: 0, data2: 0, reserved: 0)
status = MusicTrackNewMIDIChannelEvent(track!, 0, &chanmess)
if status != noErr {
print("creating bank select event \(status)")
}
// then the least significant byte
chanmess = MIDIChannelMessage(status: 0xB0 | sequencerMidiChannel, data1: 32, data2: 0, reserved: 0)
status = MusicTrackNewMIDIChannelEvent(track!, 0, &chanmess)
if status != noErr {
print("creating bank select event \(status)")
}
// set the voice
chanmess = MIDIChannelMessage(status: 0xC0 | sequencerMidiChannel, data1: UInt8(0), data2: 0, reserved: 0)
status = MusicTrackNewMIDIChannelEvent(track!, 0, &chanmess)
if status != noErr {
print("creating program change event \(status)")
}
CheckError(MusicSequenceSetAUGraph(musicSequence!, audioGraph))
CheckError(NewMusicPlayer(&musicPlayer))
CheckError(MusicPlayerSetSequence(musicPlayer!, musicSequence))
CheckError(MusicPlayerPreroll(musicPlayer!))
}
func loadnewSoundFont() {
var bankURL = Bundle.main.url(forResource: "Arachno SoundFont - Version 1.0", withExtension: "sf2")
CheckError(AudioUnitSetProperty(synthUnit!, AudioUnitPropertyID(kMusicDeviceProperty_SoundBankURL), AudioUnitScope(kAudioUnitScope_Global), 0, &bankURL, UInt32(MemoryLayout<URL>.size)))
}
func loadPatch(patchNo: Int) {
let channel = UInt32(0)
var enabled = UInt32(1)
var disabled = UInt32(0)
patch = UInt32(patchNo)
CheckError(AudioUnitSetProperty(
synthUnit!,
AudioUnitPropertyID(kAUMIDISynthProperty_EnablePreload),
AudioUnitScope(kAudioUnitScope_Global),
0,
&enabled,
UInt32(MemoryLayout<UInt32>.size)))
let programChangeCommand = UInt32(0xC0 | channel)
CheckError(MusicDeviceMIDIEvent(self.synthUnit!, programChangeCommand, patch, 0, 0))
CheckError(AudioUnitSetProperty(
synthUnit!,
AudioUnitPropertyID(kAUMIDISynthProperty_EnablePreload),
AudioUnitScope(kAudioUnitScope_Global),
0,
&disabled,
UInt32(MemoryLayout<UInt32>.size)))
// the previous programChangeCommand just triggered a preload
// this one actually changes to the new voice
CheckError(MusicDeviceMIDIEvent(synthUnit!, programChangeCommand, patch, 0, 0))
}
func play(number: UInt8) {
sampler.startNote(number, withVelocity: 127, onChannel: 0)
}
func stop(number: UInt8) {
sampler.stopNote(number, onChannel: 0)
}
func musicPlayerPlay() {
var status = noErr
var playing:DarwinBoolean = false
CheckError(MusicPlayerIsPlaying(musicPlayer!, &playing))
if playing != false {
status = MusicPlayerStop(musicPlayer!)
if status != noErr {
print("Error stopping \(status)")
CheckError(status)
return
}
}
CheckError(MusicPlayerSetTime(musicPlayer!, 0))
CheckError(MusicPlayerStart(musicPlayer!))
}
var avsequencer: AVAudioSequencer!
var sequencerMode = 1
var sequenceStartTime: Date?
var noteOnTimes = [Date] (repeating: Date(), count:128)
var musicSequence: MusicSequence?
var midisequencer = AKSequencer()
// var musicPlayer: MusicPlayer?
let sequencerMidiChannel = UInt8(1)
var midisynthUnit: AudioUnit?
//track is the variable the notes are written on
var track: MusicTrack?
var newtrack: AKMusicTrack?
func setupSequencer(name: String) {
self.avsequencer = AVAudioSequencer(audioEngine: self.engine)
let options = AVMusicSequenceLoadOptions.smfChannelsToTracks
if let fileURL = Bundle.main.url(forResource: name, withExtension: "mid") {
do {
try avsequencer.load(from: fileURL, options: options)
print("loaded \(fileURL)")
} catch {
print("something screwed up \(error)")
return
}
}
avsequencer.prepareToPlay()
}
func playsequence() {
if avsequencer.isPlaying {
stopsequence()
}
avsequencer.currentPositionInBeats = TimeInterval(0)
do {
try avsequencer.start()
} catch {
print("cannot start \(error)")
}
}
func creatnewtrck(){
let sequencelegnth = AKDuration(beats: 8.0)
newtrack = midisequencer.newTrack()
}
func addnotestotrack(){
// AKMIDISampler
}
func stopsequence() {
avsequencer.stop()
}
func setSequencerMode(mode: Int) {
sequencerMode = mode
switch(sequencerMode) {
case SequencerMode.off.rawValue:
print(mode)
// CheckError(osstatus: MusicPlayerStop(musicPlayer!))
case SequencerMode.recording.rawValue:
print(mode)
case SequencerMode.playing.rawValue:
print(mode)
default:
break
}
}
/* func noteOn(note: UInt8) {
let noteCommand = UInt32(0x90 | midiChannel)
let base = note - 48
let octaveAdjust = (UInt8(octave) * 12) + base
let pitch = UInt32(octaveAdjust)
CheckError(MusicDeviceMIDIEvent(self.midisynthUnit!,
noteCommand, pitch, UInt32(self.midiVelocity), 0))
}
func noteOff(note: UInt8) {
let channel = UInt32(0)
let noteCommand = UInt32(0x80 | channel)
let base = note - 48
let octaveAdjust = (UInt8(octave) * 12) + base
let pitch = UInt32(octaveAdjust)
CheckError(MusicDeviceMIDIEvent(self.midisynthUnit!,
noteCommand, pitch, 0, 0))
}*/
func noteOn(note: UInt8) {
if sequencerMode == SequencerMode.recording.rawValue {
print("recording sequence note")
noteOnTimes[Int(note)] = Date()
} else {
print("no notes")
}
}
func noteOff(note: UInt8, timestamp: Float64, sequencetime: Date) {
if sequencerMode == SequencerMode.recording.rawValue {
let duration: Double = Date().timeIntervalSince(noteOnTimes[Int(note)])
let onset: Double = noteOnTimes[Int(note)].timeIntervalSince(sequencetime)
//the order of the notes in the array
var beat: MusicTimeStamp = 0
CheckError(MusicSequenceGetBeatsForSeconds(musicSequence!, onset, &beat))
var mess = MIDINoteMessage(channel: sequencerMidiChannel,
note: note,
velocity: midiVelocity,
releaseVelocity: 0,
duration: Float(duration) )
CheckError(MusicTrackNewMIDINoteEvent(track!, timestamp, &mess))
}
}
}
The code that plays the collection of notes
_ = sample.midisequencer.newTrack()
let sequencelegnth = AKDuration(beats: 8.0)
sample.midisequencer.setLength(sequencelegnth)
sample.sequenceStartTime = format.date(from: format.string(from: NSDate() as Date))
sample.midisequencer.setTempo(160.0)
sample.midisequencer.enableLooping()
sample.midisequencer.play()
这是更改音色的代码
func loadSF2PresetIntoSampler(_ preset: UInt8) {
guard let bankURL = Bundle.main.url(forResource: "Arachno SoundFont - Version 1.0", withExtension: "sf2") else {
print("could not load sound font")
return
}
let folder = bankURL.path
do {
try self.sampler.loadSoundBankInstrument(at: bankURL,
program: preset,
bankMSB: UInt8(kAUSampler_DefaultMelodicBankMSB),
bankLSB: UInt8(kAUSampler_DefaultBankLSB))
try midisampler.loadSoundFont(folder, preset: 0, bank: kAUSampler_DefaultBankLSB)
// try midisampler.loadPath(bankURL.absoluteString)
} catch {
print("error loading sound bank instrument")
}
}
midisampler 是一个 AKMidisampler。
至少，您需要将 AKSequencer 连接到某种输出以使其发出声音。对于旧版本（现在称为 AKAppleSequencer），如果您没有明确设置输出，您将听到默认的（哔哔声）采样器。
例如，在 AKAppleSequencer（在 AudioKit 4.8 中，或 AKSequencer 早期版本）
let track = seq.newTrack()
track!.setMIDIOutput(sampler.midiIn)
上新AKSequencer
let track = seq.newTrack() // for the new AKSequencer, in AudioKit 4.8
track!.setTarget(node: sampler)
此外，请确保您已在项目的功能中启用音频背景模式，因为缺少此步骤，这也会为您提供默认采样器。
你已经包含了大量的代码（我没有试图吸收这里发生的所有事情）但是事实上你正在使用 MusicSequence 和 [=12 的实例=]（我怀疑是旧版本，现在称为 AKAppleSequencer，它只是 MusicSequence 的包装）是一个危险信号。
我正在使用 Audiokit API 创建一个函数，用户将音符按到屏幕上，然后根据他们选择的 SoundFont 发出声音。然后我让他们收集大量笔记，让他们按照他们选择的顺序播放。
问题是我正在使用 AKSequencer 来回放音符，而当 AKSequencer 回放音符时，它听起来不像 SoundFont。它发出哔声。
是否有代码可以让我更改 AKSequencer 发出的声音？
我正在使用音频套件来执行此操作。
示例是一个 NSObject，其中包含 midisampler、播放器等。这是代码
class Sampler1: NSObject {
var engine = AVAudioEngine()
var sampler: AVAudioUnitSampler!
var midisampler = AKMIDISampler()
var octave = 4
let midiChannel = 0
var midiVelocity = UInt8(127)
var audioGraph: AUGraph?
var musicPlayer: MusicPlayer?
var patch = UInt32(0)
var synthUnit: AudioUnit?
var synthNode = AUNode()
var outputNode = AUNode()
override init() {
super.init()
// engine = AVAudioEngine()
sampler = AVAudioUnitSampler()
engine.attach(sampler)
engine.connect(sampler, to: engine.mainMixerNode, format: nil)
loadSF2PresetIntoSampler(5)
/* sampler2 = AVAudioUnitSampler()
engine.attachNode(sampler2)
engine.connect(sampler2, to: engine.mainMixerNode, format: nil)
*/
addObservers()
startEngine()
setSessionPlayback()
/* CheckError(NewAUGraph(&audioGraph))
createOutputNode(audioGraph: audioGraph!, outputNode: &outputNode)
createSynthNode()
CheckError(AUGraphNodeInfo(audioGraph!, synthNode, nil, &synthUnit))
let synthOutputElement: AudioUnitElement = 0
let ioUnitInputElement: AudioUnitElement = 0
CheckError(AUGraphConnectNodeInput(audioGraph!, synthNode, synthOutputElement,
outputNode, ioUnitInputElement))
CheckError(AUGraphInitialize(audioGraph!))
CheckError(AUGraphStart(audioGraph!))
loadnewSoundFont()
loadPatch(patchNo: 0)*/
setUpSequencer()
}
func createOutputNode(audioGraph: AUGraph, outputNode: UnsafeMutablePointer<AUNode>) {
var cd = AudioComponentDescription(
componentType: OSType(kAudioUnitType_Output),
componentSubType: OSType(kAudioUnitSubType_RemoteIO),
componentManufacturer: OSType(kAudioUnitManufacturer_Apple),
componentFlags: 0,componentFlagsMask: 0)
CheckError(AUGraphAddNode(audioGraph, &cd, outputNode))
}
func loadSF2PresetIntoSampler(_ preset: UInt8) {
guard let bankURL = Bundle.main.url(forResource: "Arachno SoundFont - Version 1.0", withExtension: "sf2") else {
print("could not load sound font")
return
}
let folder = bankURL.path
do {
try self.sampler.loadSoundBankInstrument(at: bankURL,
program: preset,
bankMSB: UInt8(kAUSampler_DefaultMelodicBankMSB),
bankLSB: UInt8(kAUSampler_DefaultBankLSB))
try midisampler.loadSoundFont(folder, preset: 0, bank: kAUSampler_DefaultBankLSB)
// try midisampler.loadPath(bankURL.absoluteString)
} catch {
print("error loading sound bank instrument")
}
}
func createSynthNode() {
var cd = AudioComponentDescription(
componentType: OSType(kAudioUnitType_MusicDevice),
componentSubType: OSType(kAudioUnitSubType_MIDISynth),
componentManufacturer: OSType(kAudioUnitManufacturer_Apple),
componentFlags: 0,componentFlagsMask: 0)
CheckError(AUGraphAddNode(audioGraph!, &cd, &synthNode))
}
func setSessionPlayback() {
let audioSession = AVAudioSession.sharedInstance()
do {
try
audioSession.setCategory(AVAudioSession.Category.playback, options:
AVAudioSession.CategoryOptions.mixWithOthers)
} catch {
print("couldn't set category \(error)")
return
}
do {
try audioSession.setActive(true)
} catch {
print("couldn't set category active \(error)")
return
}
}
func startEngine() {
if engine.isRunning {
print("audio engine already started")
return
}
do {
try engine.start()
print("audio engine started")
} catch {
print("oops \(error)")
print("could not start audio engine")
}
}
func addObservers() {
NotificationCenter.default.addObserver(self,
selector:"engineConfigurationChange:",
name:NSNotification.Name.AVAudioEngineConfigurationChange,
object:engine)
NotificationCenter.default.addObserver(self,
selector:"sessionInterrupted:",
name:AVAudioSession.interruptionNotification,
object:engine)
NotificationCenter.default.addObserver(self,
selector:"sessionRouteChange:",
name:AVAudioSession.routeChangeNotification,
object:engine)
}
func removeObservers() {
NotificationCenter.default.removeObserver(self,
name: NSNotification.Name.AVAudioEngineConfigurationChange,
object: nil)
NotificationCenter.default.removeObserver(self,
name: AVAudioSession.interruptionNotification,
object: nil)
NotificationCenter.default.removeObserver(self,
name: AVAudioSession.routeChangeNotification,
object: nil)
}
private func setUpSequencer() {
// set the sequencer voice to storedPatch so we can play along with it using patch
var status = NewMusicSequence(&musicSequence)
if status != noErr {
print("\(#line) bad status \(status) creating sequence")
}
status = MusicSequenceNewTrack(musicSequence!, &track)
if status != noErr {
print("error creating track \(status)")
}
// 0xB0 = bank select, first we do the most significant byte
var chanmess = MIDIChannelMessage(status: 0xB0 | sequencerMidiChannel, data1: 0, data2: 0, reserved: 0)
status = MusicTrackNewMIDIChannelEvent(track!, 0, &chanmess)
if status != noErr {
print("creating bank select event \(status)")
}
// then the least significant byte
chanmess = MIDIChannelMessage(status: 0xB0 | sequencerMidiChannel, data1: 32, data2: 0, reserved: 0)
status = MusicTrackNewMIDIChannelEvent(track!, 0, &chanmess)
if status != noErr {
print("creating bank select event \(status)")
}
// set the voice
chanmess = MIDIChannelMessage(status: 0xC0 | sequencerMidiChannel, data1: UInt8(0), data2: 0, reserved: 0)
status = MusicTrackNewMIDIChannelEvent(track!, 0, &chanmess)
if status != noErr {
print("creating program change event \(status)")
}
CheckError(MusicSequenceSetAUGraph(musicSequence!, audioGraph))
CheckError(NewMusicPlayer(&musicPlayer))
CheckError(MusicPlayerSetSequence(musicPlayer!, musicSequence))
CheckError(MusicPlayerPreroll(musicPlayer!))
}
func loadnewSoundFont() {
var bankURL = Bundle.main.url(forResource: "Arachno SoundFont - Version 1.0", withExtension: "sf2")
CheckError(AudioUnitSetProperty(synthUnit!, AudioUnitPropertyID(kMusicDeviceProperty_SoundBankURL), AudioUnitScope(kAudioUnitScope_Global), 0, &bankURL, UInt32(MemoryLayout<URL>.size)))
}
func loadPatch(patchNo: Int) {
let channel = UInt32(0)
var enabled = UInt32(1)
var disabled = UInt32(0)
patch = UInt32(patchNo)
CheckError(AudioUnitSetProperty(
synthUnit!,
AudioUnitPropertyID(kAUMIDISynthProperty_EnablePreload),
AudioUnitScope(kAudioUnitScope_Global),
0,
&enabled,
UInt32(MemoryLayout<UInt32>.size)))
let programChangeCommand = UInt32(0xC0 | channel)
CheckError(MusicDeviceMIDIEvent(self.synthUnit!, programChangeCommand, patch, 0, 0))
CheckError(AudioUnitSetProperty(
synthUnit!,
AudioUnitPropertyID(kAUMIDISynthProperty_EnablePreload),
AudioUnitScope(kAudioUnitScope_Global),
0,
&disabled,
UInt32(MemoryLayout<UInt32>.size)))
// the previous programChangeCommand just triggered a preload
// this one actually changes to the new voice
CheckError(MusicDeviceMIDIEvent(synthUnit!, programChangeCommand, patch, 0, 0))
}
func play(number: UInt8) {
sampler.startNote(number, withVelocity: 127, onChannel: 0)
}
func stop(number: UInt8) {
sampler.stopNote(number, onChannel: 0)
}
func musicPlayerPlay() {
var status = noErr
var playing:DarwinBoolean = false
CheckError(MusicPlayerIsPlaying(musicPlayer!, &playing))
if playing != false {
status = MusicPlayerStop(musicPlayer!)
if status != noErr {
print("Error stopping \(status)")
CheckError(status)
return
}
}
CheckError(MusicPlayerSetTime(musicPlayer!, 0))
CheckError(MusicPlayerStart(musicPlayer!))
}
var avsequencer: AVAudioSequencer!
var sequencerMode = 1
var sequenceStartTime: Date?
var noteOnTimes = [Date] (repeating: Date(), count:128)
var musicSequence: MusicSequence?
var midisequencer = AKSequencer()
// var musicPlayer: MusicPlayer?
let sequencerMidiChannel = UInt8(1)
var midisynthUnit: AudioUnit?
//track is the variable the notes are written on
var track: MusicTrack?
var newtrack: AKMusicTrack?
func setupSequencer(name: String) {
self.avsequencer = AVAudioSequencer(audioEngine: self.engine)
let options = AVMusicSequenceLoadOptions.smfChannelsToTracks
if let fileURL = Bundle.main.url(forResource: name, withExtension: "mid") {
do {
try avsequencer.load(from: fileURL, options: options)
print("loaded \(fileURL)")
} catch {
print("something screwed up \(error)")
return
}
}
avsequencer.prepareToPlay()
}
func playsequence() {
if avsequencer.isPlaying {
stopsequence()
}
avsequencer.currentPositionInBeats = TimeInterval(0)
do {
try avsequencer.start()
} catch {
print("cannot start \(error)")
}
}
func creatnewtrck(){
let sequencelegnth = AKDuration(beats: 8.0)
newtrack = midisequencer.newTrack()
}
func addnotestotrack(){
// AKMIDISampler
}
func stopsequence() {
avsequencer.stop()
}
func setSequencerMode(mode: Int) {
sequencerMode = mode
switch(sequencerMode) {
case SequencerMode.off.rawValue:
print(mode)
// CheckError(osstatus: MusicPlayerStop(musicPlayer!))
case SequencerMode.recording.rawValue:
print(mode)
case SequencerMode.playing.rawValue:
print(mode)
default:
break
}
}
/* func noteOn(note: UInt8) {
let noteCommand = UInt32(0x90 | midiChannel)
let base = note - 48
let octaveAdjust = (UInt8(octave) * 12) + base
let pitch = UInt32(octaveAdjust)
CheckError(MusicDeviceMIDIEvent(self.midisynthUnit!,
noteCommand, pitch, UInt32(self.midiVelocity), 0))
}
func noteOff(note: UInt8) {
let channel = UInt32(0)
let noteCommand = UInt32(0x80 | channel)
let base = note - 48
let octaveAdjust = (UInt8(octave) * 12) + base
let pitch = UInt32(octaveAdjust)
CheckError(MusicDeviceMIDIEvent(self.midisynthUnit!,
noteCommand, pitch, 0, 0))
}*/
func noteOn(note: UInt8) {
if sequencerMode == SequencerMode.recording.rawValue {
print("recording sequence note")
noteOnTimes[Int(note)] = Date()
} else {
print("no notes")
}
}
func noteOff(note: UInt8, timestamp: Float64, sequencetime: Date) {
if sequencerMode == SequencerMode.recording.rawValue {
let duration: Double = Date().timeIntervalSince(noteOnTimes[Int(note)])
let onset: Double = noteOnTimes[Int(note)].timeIntervalSince(sequencetime)
//the order of the notes in the array
var beat: MusicTimeStamp = 0
CheckError(MusicSequenceGetBeatsForSeconds(musicSequence!, onset, &beat))
var mess = MIDINoteMessage(channel: sequencerMidiChannel,
note: note,
velocity: midiVelocity,
releaseVelocity: 0,
duration: Float(duration) )
CheckError(MusicTrackNewMIDINoteEvent(track!, timestamp, &mess))
}
}
}
The code that plays the collection of notes
_ = sample.midisequencer.newTrack()
let sequencelegnth = AKDuration(beats: 8.0)
sample.midisequencer.setLength(sequencelegnth)
sample.sequenceStartTime = format.date(from: format.string(from: NSDate() as Date))
sample.midisequencer.setTempo(160.0)
sample.midisequencer.enableLooping()
sample.midisequencer.play()
这是更改音色的代码
func loadSF2PresetIntoSampler(_ preset: UInt8) {
guard let bankURL = Bundle.main.url(forResource: "Arachno SoundFont - Version 1.0", withExtension: "sf2") else {
print("could not load sound font")
return
}
let folder = bankURL.path
do {
try self.sampler.loadSoundBankInstrument(at: bankURL,
program: preset,
bankMSB: UInt8(kAUSampler_DefaultMelodicBankMSB),
bankLSB: UInt8(kAUSampler_DefaultBankLSB))
try midisampler.loadSoundFont(folder, preset: 0, bank: kAUSampler_DefaultBankLSB)
// try midisampler.loadPath(bankURL.absoluteString)
} catch {
print("error loading sound bank instrument")
}
}
midisampler 是一个 AKMidisampler。
至少，您需要将 AKSequencer 连接到某种输出以使其发出声音。对于旧版本（现在称为 AKAppleSequencer），如果您没有明确设置输出，您将听到默认的（哔哔声）采样器。
例如，在 AKAppleSequencer（在 AudioKit 4.8 中，或 AKSequencer 早期版本）
let track = seq.newTrack()
track!.setMIDIOutput(sampler.midiIn)
上新AKSequencer
let track = seq.newTrack() // for the new AKSequencer, in AudioKit 4.8
track!.setTarget(node: sampler)
此外，请确保您已在项目的功能中启用音频背景模式，因为缺少此步骤，这也会为您提供默认采样器。
你已经包含了大量的代码（我没有试图吸收这里发生的所有事情）但是事实上你正在使用 MusicSequence 和 [=12 的实例=]（我怀疑是旧版本，现在称为 AKAppleSequencer，它只是 MusicSequence 的包装）是一个危险信号。