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?
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.
Related
Thanks for AudioKit !
I have next question:
I'm trying to get ideal sync playing of AKSampleMetronome and one midi file wrapped in AKMIDISampler. Here is my code:
let metronome = AKSamplerMetronome()
let mixer = AKMixer()
let midiSampler = AKMIDISampler()
midiSampler.samplerUnit.loadSoundBankInstrument(....)
metronome >>> mixer
midiSampler >>> mixer
AudioKit.output = mixer
AudioKit.start()
let sequencer = AKAppleSequencer(filename: "midifilename")
sequencer.enableLooping()
sequencer.tracks[1].setMIDIOutput(midiSampler.midiIn)
//now play
sequencer.play()
metronome.beatTime = 0
metronome.play()
But when I'm changing tempo like this:
sequencer.setTempo(bpm)
let now = AVAudioTime(hostTime: mach_absolute_time())
metronome.setTempo(Double(bpm), at: now)
After a while the sound of metronome and midi sequencer diverges.
How can I achieve accurate solution for this ?
Lots of ways to do this but I would make one of the tracks in the sequencer a metronome track and send that midi signal to a midiSampler.
I'm implementing an app utilizing AudioKit that allows you to play a large number of audio files and switch between them at any time. Additionally we need one audio file to play on loop for ambient noise.
What is the correct way to dynamically change players in AudioKit's output? Or what's the proper way to implement this behavior?
AudioKit requires you set its output which can be an AKPlayer that plays one audio file or an AKMixer given an array of AKPlayers for example. You cannot change the output once AudioKit has been started as I saw previously. So currently my approach is to use AKMixer to play two AKPlayers - one for the current file and one for the ambient noise. When the user taps the 'Next' button I stop() AudioKit, recreate an AKMixer with a new player for the next song's audio file and the ambient noise player, assign that to output, start() AudioKit, and play both players. This results in undesirable behavior because playback of the ambient noise is stopped when switching songs resulting in a brief pause.
If this is the correct approach, how can we update the output without stopping AudioKit? I wondered if you can initialize the mixer with an array of players that's a strongly held property and simply add/remove players in the array. But that doesn't work - starting a new player throws an error player started when in a disconnected state because this node is not attached to the output.
I've created a sample project to demonstrate this behavior. When launched the app plays drums as ambient noise and waves for the current track. When you tap Next it'll switch to the next track (which in this demo code is just the same audio file) and you can hear the drums stop and then resume which is undesirable. I've included the project's code below:
final class Maestro: NSObject {
static let shared = Maestro()
private var audioPlayer: AKPlayer?
private var ambientPlayer: AKPlayer = {
let player = AKPlayer(url: Bundle.main.url(forResource: "drums", withExtension: "wav")!)!
player.isLooping = true
return player
}()
private var mixer: AKMixer?
private let audioFileURL = Bundle.main.url(forResource: "waves", withExtension: "mp3")!
func play() {
playNewPlayer(fileURL: audioFileURL)
}
func next() {
//In the real app we'd play the next audio file in the playlist but for the demo we'll just play the same file
playNewPlayer(fileURL: audioFileURL)
}
private func playNewPlayer(fileURL: URL) {
audioPlayer?.stop()
audioPlayer = nil
do {
try AudioKit.stop()
} catch {
print("Maestro AudioKit.stop error: \(error)")
}
audioPlayer = AKPlayer(url: fileURL)!
mixer = AKMixer([audioPlayer!, ambientPlayer])
AudioKit.output = mixer
do {
try AudioKit.start()
} catch {
print("Maestro AudioKit.start error: \(error)")
}
if ambientPlayer.isPlaying {
//need to resume playback from current position
let pos = ambientPlayer.currentTime
ambientPlayer.stop()
ambientPlayer.play(from: pos)
} else {
ambientPlayer.play()
}
audioPlayer?.play()
}
}
I’m having a problem using AKMIDISampler in my project when there’s an initialized AKMicrophone. Along with correctly playing the woodblock sample when “play” is called on the sampler, the first time “play” is called a constant sine wave starts playing - it never stops.
I’ve replicated the problem in the smallest amount of code below. Issue happens when the class is initialized then playTestSample() is called.
Note that if the AKMicrophone related code is all muted the AKMIDISampler plays fine and the sine wave that currently haunts my dreams doesn’t happen.
(I’ve tried switching to use the AKSampler() just to see if the problem would exist there but I haven’t been able to get any sound out of that).
Fyi: I have “App plays audio or streams audio/video using AirPlay” in the “Required background modes” in info.plist - which is know to fix another sine wave issue.
Thank you very much for any assistance.
Btw: AudioKit rocks and has been a massive help on this project! :^)
AK 4.5.4
Xcode 10.1
import Foundation
import AudioKit
class AudioKitTESTManager {
var mixer = AKMixer()
var sampler = AKMIDISampler()
var mic = AKMicrophone()
var micMixer = AKMixer()
var micBooster = AKBooster()
init() {
mixer = AKMixer(sampler, micBooster)
do {
let woodblock = try AKAudioFile(readFileName: RhythmGameConfig.woodblockSoundName)
try sampler.loadAudioFiles([woodblock])
} catch {
print("Error loading audio files into sampler")
}
micMixer = AKMixer(mic)
micBooster = AKBooster(micMixer)
micBooster.gain = 0.0
AudioKit.output = mixer
AKSettings.playbackWhileMuted = true
AKSettings.defaultToSpeaker = true
AKSettings.sampleRate = 44100
do {
print("Attempting to start AudioKit")
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
}
func playTestSample() {
// You hear the sample and a continuous sine wave starts playing through the samplerMixer
try? sampler.play(noteNumber: 60, velocity: 90, channel: 1)
}
}
Wheeew. I believe I've found a solution. Maybe it will help out someone else?
It seems that loading the files into the sampler AFTER AudioKit.start() fixes the Sine Wave of Terror!
//..
do {
print("Attempting to start AudioKit")
try AudioKit.start()
} catch {
AKLog("AudioKit did not start!")
}
do {
let woodblock = try AKAudioFile(readFileName: RhythmGameConfig.woodblockSoundName)
try sampler.loadAudioFiles([woodblock])
} catch {
print("Error loading audio files into sampler")
}
I'm having a problem with recording audio from the microphone of my test device to a .caf file in Swift, XCode 9.4.1 using the latest version of AudioKit. In a simple test whereby I send the audio straight from the microphone to the output via an AKBooster, it works just fine and I can hear the mic input coming out of the speakers. I'm more or less following this example, although again using a booster node instead of an oscillator.
The following is my code:
class MicrophoneHandler
{
var microphone : AKMicrophone!
var booster : AKBooster!
var mixer : AKMixer!
var recorder : AKNodeRecorder!
var file : AKAudioFile!
var player : AKAudioPlayer!
init()
{
setupMicrophone()
microphone = AKMicrophone()
booster = AKBooster(microphone) // Stereo amplifier for microphone
mixer = AKMixer(booster)
file = try! AKAudioFile() // File to store recorder output
player = try? AKAudioPlayer(file: file) // Player to play back recorded audio file
//player.looping = true
recorder = try? AKNodeRecorder(node: mixer, file: file)
try? recorder.record()
sleep(5)
let dur = String(format: "%0.3f seconds", recorder.recordedDuration)
print("Stopped. (\(dur) recorded)")
recorder.stop()
//file.exportAsynchronously(name: "Test", baseDir: .documents, exportFormat: .caf){ [weak self] _, _ in
//}
//player.play()
//AudioKit.output = player!
//try? AudioKit.start()
}
func setupMicrophone()
{
// Function to initialise microphone settings
// Adapted from AudioKit example code found here:
// https://audiokit.io/examples/MicrophoneAnalysis
AKSettings.bufferLength = .medium
AKSettings.ioBufferDuration = 0.002 // TODO experiment with this to control latency
do
{
try AKSettings.setSession(category: .playAndRecord, with: .allowBluetoothA2DP) // Set session type & allow streaming to Bluetooth devices
} catch
{
AKLog("Could not set session category.")
}
AKSettings.defaultToSpeaker = true // Output to speaker when audio input is enabled
}
}
I have commented out the export code as the problem doesn't appear to be here. The console displays the following:
AKMicrophone.swift:init():45:Mixer inputs 8
AKAudioPlayer.swift:updatePCMBuffer():533:AKAudioPlayer Warning: "BF848EC0-94F8-4E39-A211-784B001CED72.caf" is an empty file
2018-11-16 17:49:16.936169+0000 VoxBox[2258:6984570] Audio files cannot be non-interleaved. Ignoring setting AVLinearPCMIsNonInterleaved YES.
AKNodeRecorder.swift:record():104:AKNodeRecorder: recording
Stopped. (0.000 seconds recorded)
As you can see, the recorder appears not to be recording to file for some reason. To my mind, my code should
Initialise the microphone (including settings)
Route the microphone input through a booster followed by a mixer (mixing with an FX bank will happen later)
Create an empty .caf audio file to be written to
Set up a player to play this file when the time comes
Set up a recorder to record the output of the mixer node to the audio file
Record 5 seconds of microphone input to the audio file
Yet for some reason nothing is being recorded. Clearly I am missing something or have misunderstood how the AKNodeRecorder works in this regard. I have read as many StackOverflow questions on similar topics as I can, had a dig through the AudioKit documentation and read a couple of examples from the AudioKit site, but nothing seems to address my particular problem.
Any help would be much appreciated.
I have an AKSequencer which has an AKMusicTrack inside of it with the output of an AKMIDISampler. I also load the AKMIDISampler with a soundfont file.
The problem that I'm facing with AudioKit's renderToFile is that when it does create the file the sound is empty/silent, or it will play a single note which will be at the very beginning of the file, as well as only playing the single note a strange sound is played for the entirety of the length.
Here's the code for the initialisation
let midiSampler = AKMIDISampler()
let sequencer = AKSequencer()
let midi = AKMIDI()
do {
try midiSampler.loadSoundFont("soundFontFile", preset: 0, bank: 0)
} catch {
AKLog("Error - Couldn't load Sample!!!")
}
AudioKit.output = midiSampler
do {
try AudioKit.start()
} catch {
AKLog("AudioKit didn't begin")
}
let drumTrack = sequencer.newTrack("Drum Track")
midi.openInput()
midiSampler.enableMIDI(midi.client, name: "MIDI Sampler MIDI In")
drumTrack.setMIDIOutput(midiSampler.midiIn)
sequencer.setLength(AKDuration(beats: 8))
sequencer.setTempo(136)
sequencer.setRate(40)
midi = AudioKit.midi
Here is how I attempt to renderToFile:
let path = "recordedMIDIAudio.caf"
let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent(path)
let format = AVAudioFormat(commonFormat: .pcmFormatFloat64, sampleRate: 44100, channels: 1, interleaved: true)!
do {
let audioFile = try AKAudioFile(forWriting: url, settings: format.settings, commonFormat: format.commonFormat, interleaved: format.isInterleaved)
try AudioKit.renderToFile(audioFile, duration: 3.55, prerender: {
self.sequencer.play()
})
} catch {
AKLog("Error when converting")
}
I've done quite a lot of research on this particular issue but I've had no luck. Any help or pointers will be greatly appreciated, thanks in advance!
Unfortunately its a well known but probably not well enough documented fact that offline rendering does not work with MIDI based signal generation. The time clock that the midi system uses is not sped up with the speed of sample generation that happens when rendering to a file.