I want to get the volume of AKAmplitudeTracker but getting -inf what is wrong with me please help out.
AKAudioFile.cleanTempDirectory()
AKSettings.audioInputEnabled = true
AKSettings.bufferLength = .medium
AKSettings.defaultToSpeaker = true
AKSettings.playbackWhileMuted = true
AKSettings.enableRouteChangeHandling = true
AKSettings.enableCategoryChangeHandling = true
AKSettings.enableLogging = true
do {
try AKSettings.setSession(category: .playAndRecord, with: .allowBluetoothA2DP)
} catch {
print("error \(error.localizedDescription)")
}
microphone = AKMicrophone()!
tracker = AKAmplitudeTracker(microphone)
booster = AKBooster(tracker, gain: 0)
AudioKit.output = booster
try AudioKit.start()
=================
extension AKAmplitudeTracker {
var volume: Decibel {
return 20.0 * log10(amplitude)
}
}
=================
OutPut print(tracker. amplitude)
0.0
Had a quick look, seems that you followed the basic setup, you do seem to fail to trace the data generated in time correctly! Amplitude data is provided during the time period for the computation that is taken from the microphone, so to look at what it looks like in timeline you can use a timer, as such:
func reset() throws {
do {
self.timer.invalidate()
self.timer = nil
} catch {
throw error
}
}
func microphoneTracker() {
guard self.timer == nil else { return }
self.watcher()
let timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { _ in
log.info(self.akMicrophoneAmplitudeTracker.amplitude)
}
self.timer = timer
}
Change the withTimeInterval to how frequently you want to check the amplitude.
I think it's quite readable what I put there for you, but I'll break it down in a few words:
Keep a reference for the AKAmplitudeTracker in a property, here I've named it akMicrophoneAmplitudeTracker
Keep a reference for your timed event, that will check the amplitude value during a period
Compute the data in the closure body, the property holding value is .amplitude
The computation in the example is a logger that prints .amplitude
As required, use the .invalidate method to stop the timer
A few other things you may want to double-check on your code is to make sure that the tracker is part of the signal chain, as that's an AVAudioEngine engine requirement; I've also noticed in some other people's code a call for the method .start in the AKAmplitudeTracker, as follows:
akMicrophoneAmplitudeTracker.start()
To finish, have in mind that if you are testing it through Simulator, look at the microphone settings of your host-machine and expect amplitudes that might be different then the actual hardware.
I'm using AudioKit to run an AKSequencer() that plays both mp3 and wav files using AKMIDISampler(). Everything works great, except in cases when the app has entered background state for more than 30+ min, and then brought back up again for use. It seems to then lose all of it's audio connections and plays the "missing file" sinewave tone mentioned in other threads. The app can happily can enter background momentarily, user can quit, etc without the tone. It seems to only happen when left in background for long periods of time and then brought up again.
I've tried changing the order of AudioKit.start() and file loading, but nothing seems to completely eliminate the issue.
My current workaround is simply to prevent the user's display from timing out, however that does not address many use-cases of the issue occurring.
Is there a way to handle whatever error I'm setting up that creates this tone? Here is a representative example of what I'm doing with ~40 audio files.
//viewController
override func viewDidLoad() {
sequencer.setupSequencer()
}
class SamplerWav {
let audioWav = AKMIDISampler()
func loadWavFile() {
try? audioWav.loadWav("some_wav_audio_file")
}
class SamplerMp3 {
let audioMp3 = AKMIDISampler()
let audioMp3_akAudioFile = try! AKAudioFile(readFileName: "some_other_audio_file.mp3")
func loadMp3File() {
try? audioMp3.loadAudioFile(audioMp3_akAudioFile)
}
class Sequencer {
let mixer = AKMixer()
let subMix = AKMixer()
let samplerWav = SamplerWav()
let samplerMp3 = SamplerMp3()
var callbackTrack: AKMusicTrack!
let callbackInstr = AKMIDICallbackInstrument()
func setupSequencer{
AudioKit.output = mixer.mixer
try! AudioKit.start()
callbackTrack = sequencer.newTrack()
callbackTrack?.setMIDIOutput(callbackInstr.midiIn)
samplerWav.loadWavFile()
samplerMp3.loadMp3File()
samplerWav.audioWav >>> subMix
samplerMp3.audioMp3 >>> submix
submix >>> mixer
}
//Typically run from a callback track
func playbackSomeSound(){
try? samplerWav.audioWav.play(noteNumber: 60, velocity: 100, channel: 1)
}
}
Thanks! I'm a big fan of AudioKit.
After some trial and error, here's a workflow that seems to address the issue for my circumstance:
-create my callback track(s) -once- from viewDidLoad
-stop AudioKit, and call .detach() on all my AKMIDISampler tracks and any routing in willResignActive
-start AudioKit (again), and reload and reroute all of the audio files/tracks from didBecomeActive
I am trying to capture FFT data from a microphone. I've managed to get it to work before with a similar codebase but since macOS Mojave it's broken - the fft data constantly stays 0.
Relevant Code:
var fft: AKFFTTap?
var inputDevice: AKDevice? {
didSet {
inputNode = nil
updateAudioNode()
}
}
var inputNode: AKNode? {
didSet {
if fft != nil {
// According to AKFFTTap class reference, it will always be on tap 0
oldValue?.avAudioNode.removeTap(onBus: 0)
}
fft = inputNode.map { AKFFTTap($0) }
}
}
[...]
guard let device = inputDevice else {
inputNode = ViewController.shared.player.mixer
return
}
do {
try AudioKit.setInputDevice(device)
}
catch {
print("Error setting input device: \(error)")
return
}
let microphoneNode = AKMicrophone()
do {
try microphoneNode.setDevice(device)
}
catch {
print("Failed setting node input device: \(error)")
return
}
microphoneNode.start()
microphoneNode.volume = 3
print("Switched Node: \(microphoneNode), started: \(microphoneNode.isStarted)")
inputNode = microphoneNode
try! AudioKit.start()
All the code is called, no errors are output, but the fft simply stays blank. With some code reordering I get varying errors.
A full version of the class, for completeness, is here.
Finally, I also tried implementing one to one the examples from the playground. Since XCode playgrounds seem to crash with AudioKit, I tried it in my own codebase, but there's no difference there either. AKFrequencyTracker, for example, gets 0s for both amplitude and frequency.
I am not 100% positive of this, but I'd like you to try AudioKit v4.5.1 out. We definitely fixed a bug in AKMicrophone, and that could have downstream consequences. I'll withdraw this answer and keep looking if it is not fixed. Let me know.
I have a question how to correctly call CIDetector correctly I'm trying to run the face detection in real-time this works very well. However the memory consumption of the app increases linearly with time how you can see in the image below I'm thinking this is due to objects being created but they're not released can anyone advise how to do it correctly.
I have pinpointed the issue down to this function as every time it's invoked memory increases linearly when it terminated it quickly drops down to almost 80 MB instead of 11 GB rising also check for memory leaks however none were found.
My target development platform is Mac OS I'm trying to extractthe mouth position from the CA detector and then use it to compute a Delta in the mouse function for a Game.
I also Looked that this post however I have tried their approach but it did not work for me
CIDetector isn't releasing memory
fileprivate func faceDetection(){
// setting up dispatchQueue
dispatchQueue.async {
// checking if sample buffer is equal to nil if not assign its value to sample
if let sample = self.sampleBuffers {
// if allfeatures is not equal to nil. if yes assign allfeatures to features otherwise return
guard let features = self.allFeatures(sample: sample) else { return }
// loop to cycle through all features
for feature in features {
// checks if the feature is a CIFaceFeature if yes assign feature to face feature and go on.
if let faceFeature = feature as? CIFaceFeature {
if !self.hasEnded {
if self.calX.count > 30 {
self.sens.append((self.calX.max()! - self.calX.min()!))
self.sens.append((self.calY.max()! - self.calY.min()!))
print((self.calX.max()! - self.calX.min()!))
self.hasEnded = true
} else {
self.calX.append(faceFeature.mouthPosition.x)
self.calY.append(faceFeature.mouthPosition.y)
}
} else {
self.mouse(position: CGPoint(x: (faceFeature.mouthPosition.x - 300 ) * 2, y: (faceFeature.mouthPosition.y + 20 ) * 2), faceFeature: faceFeature)
}
}
}
}
if !self.faceTrackingEnds {
self.faceDetection()
}
}
}
This problem was caused by repeatedly calling the function without waiting for its completion the fix was implementing a dispatch group and then calling the function on its completion
like this Now the CIdetector runs comfortably at 200 MB memory
fileprivate func faceDetection(){
let group = DispatchGroup()
group.enter()
// setting up dispatchQueue
dispatchQueue.async {
// checking if sample buffer is equal to nil if not assign its value to sample
if let sample = self.sampleBuffers {
// if allfeatures is not equal to nil. if yes assign allfeatures to features otherwise return
guard let features = self.allFeatures(sample: sample) else { return }
// loop to cycle through all features
for feature in features {
// checks if the feature is a CIFaceFeature if yes assign feature to face feature and go on.
if let faceFeature = feature as? CIFaceFeature {
self.mouse(position: faceFeature.mouthPosition, faceFeature: faceFeature)
}
}
}
group.leave()
}
group.notify(queue: .main) {
if !self.faceTrackingEnds {
self.faceDetection()
}
}
}
How do I keep my application running in the background?
Would I have to jailbreak my iPhone to do this? I just need this app to check something from the internet every set interval and notify when needed, for my own use.
Yes, no need to jailbreak. Check out the "Implementing long-running background tasks" section of this doc from Apple.
From Apple's doc:
Declaring Your App’s Supported Background Tasks
Support for some types of background execution must be declared in advance by the app that uses them. An app declares support for a service using its Info.plist file. Add the UIBackgroundModes key to your Info.plist file and set its value to an array containing one or more of the following strings: (see Apple's doc from link mentioned above.)
I guess this is what you required
When an iOS application goes to the background, are lengthy tasks paused?
iOS Application Background Downloading
This might help you ...
Enjoy Coding :)
Use local notifications to do that. But this will not check every time. You will have to set a time where you will check your specific event, you may shorten this by decreasing your time slot. Read more about local notification to know how to achieve this at:
http://developer.apple.com/library/mac/#documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Introduction/Introduction.html
I found a way, to keep app running in background by playing silence
Make sure, that you selected audio playback in background modes
Also, don't use this method for long time, since it consumes CPU resources and battery juice, but I think it's a suitable way to keep app alive for a few minutes.
Just create an instance of SilencePlayer, call play() and then stop(), when you done
import CoreAudio
public class SilencePlayer {
private var audioQueue: AudioQueueRef? = nil
public private(set) var isStarted = false
public func play() {
if isStarted { return }
print("Playing silence")
let avs = AVAudioSession.sharedInstance()
try! avs.setCategory(AVAudioSessionCategoryPlayback, with: .mixWithOthers)
try! avs.setActive(true)
isStarted = true
var streamFormat = AudioStreamBasicDescription(
mSampleRate: 16000,
mFormatID: kAudioFormatLinearPCM,
mFormatFlags: kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked,
mBytesPerPacket: 2,
mFramesPerPacket: 1,
mBytesPerFrame: 2,
mChannelsPerFrame: 1,
mBitsPerChannel: 16,
mReserved: 0
)
let status = AudioQueueNewOutput(
&streamFormat,
SilenceQueueOutputCallback,
nil, nil, nil, 0,
&audioQueue
)
print("OSStatus for silence \(status)")
var buffers = Array<AudioQueueBufferRef?>.init(repeating: nil, count: 3)
for i in 0..<3 {
buffers[i]?.pointee.mAudioDataByteSize = 320
AudioQueueAllocateBuffer(audioQueue!, 320, &(buffers[i]))
SilenceQueueOutputCallback(nil, audioQueue!, buffers[i]!)
}
let startStatus = AudioQueueStart(audioQueue!, nil)
print("Start status for silence \(startStatus)")
}
public func stop() {
guard isStarted else { return }
print("Called stop silence")
if let aq = audioQueue {
AudioQueueStop(aq, true)
audioQueue = nil
}
try! AVAudioSession.sharedInstance().setActive(false)
isStarted = false
}
}
fileprivate func SilenceQueueOutputCallback(_ userData: UnsafeMutableRawPointer?, _ audioQueueRef: AudioQueueRef, _ bufferRef: AudioQueueBufferRef) -> Void {
let pointer = bufferRef.pointee.mAudioData
let length = bufferRef.pointee.mAudioDataByteSize
memset(pointer, 0, Int(length))
if AudioQueueEnqueueBuffer(audioQueueRef, bufferRef, 0, nil) != 0 {
AudioQueueFreeBuffer(audioQueueRef, bufferRef)
}
}
Tested on iOS 10 and Swift 4
I know this is not the answer to your question, but I think it is a solution.
This assumes that your trying to check something or get data from the internet on a regular basis?
Create a service that checks the internet every set interval for whatever it is you want to know, and create a push notification to alert you of it, if the server is down, or whatever it is your trying to monitor has changed state. Just an idea.
Yes you can do something like this. For that you need to set entry in info.plist to tell os that my app will run in background. I have done this while I wanted to pass user's location after particular time stamp to server. For that I have set "Required background modes" set to "App registers for location updates".
You can write a handler of type UIBackgroundTaskIdentifier.
You can already do this in the applicationDidEnterBackground Method