How to play MIDI with AudioKit's new AKSequencer

Question

I'm on AudioKit 4.9.1 and can't manage to play a MIDI file with the new AKSequencer (replacing AKAppleSequencer). No sound playing. Assume that MIDI file AND samples are loaded correctly since they previously worked with AKAppleSequencer. Background audio mode capability is also enabled.

Here's the relevant code: (I've also tried both AKSampler and AKAppleSampler but same result)

class MIDIPlayer {
    var sampler: AKSampler
    var legacySampler: AKAppleSampler
    var sequencer: AKSequencer

    init(withSfz sfz: String, orSf2 sf2: String, andMidiFile midiFile: String) {

        self.sampler = AKSampler()
        self.legacySampler = AKAppleSampler()
        try? legacySampler.loadSoundFont(sf2, preset: 0, bank: 0)
        sampler.loadSFZ(url: Bundle.main.url(forResource: sfz, withExtension: "sfz")!)

        AudioKit.output = sampler
        try? AudioKit.start()

        sequencer = AKSequencer(targetNode: sampler)
        // sequencer = AKSequencer(targetNode: legacySampler)

        let midi = AKMIDIFile(url: Bundle.main.url(forResource: midiFile, withExtension: "mid")!)
        sequencer.load(midiFile: midi)
    }

    func play() {
        sequencer.playFromStart()
    }

Is there some difference in how to set up the signal chain that I'm missing?

Aurelius Prochazka · Answer 1 · 2019-11-18T18:33:06.547

3

With the new sequencer, it has to be part of the signal chain. So, do something like

let mixer = AKMixer
sampler >>> mixer
for track in sequencer.tracks { track >>> mixer }
AudioKit.output = mixer

and it should work. Sorry for the delay in seeing this on Github issues.

edited Nov 18 '19 at 18:33

answered Nov 14 '19 at 18:18

Aurelius Prochazka

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I am getting a compilation error: `Cannot convert value of type 'AKSequencer' to expected argument type 'AKNode?'` – Frankie Simon Nov 18 '19 at 17:44
1

Sorry, I updated my code, it was just a pseudo code before, this should work better. – Aurelius Prochazka Nov 18 '19 at 18:33
Binary operator '>>>' cannot be applied to operands of type 'AKMusicTrack' and 'AKMixer?' – Bagusflyer Nov 29 '19 at 12:18
@Bagusflyer make sure you're using the latest AudioKit with the new AKSequencer, not the old one, which has been renamed AKAppleSequencer – Aurelius Prochazka Nov 30 '19 at 18:35
2

Any news? I'm facing something similar – NikLoy Apr 03 '20 at 21:55
@NikLoy have you found a solution? – punkbit May 05 '20 at 00:55

How to play MIDI with AudioKit's new AKSequencer

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