[英]How can i return the values of a void function
I have a function that calculate the fft of the mic input. 我有一个计算麦克风输入fft的功能。 The target is to create a framework when i call the run function the i ged the float array with all bands.
目标是在我调用run函数时创建一个框架,我将浮点数组与所有band一起调用。
Now it work all fine, but i don't know how can i return the Array in the run function from the gotSomeAudio function. 现在它工作得很好,但我不知道如何从gotSomeAudio函数返回run函数中的Array。
Thank you very much for help 非常感谢你的帮助
@objc
public class FFT:NSObject{
var audioInput: TempiAudioInput!
@objc
public func run() -> Array<Float>{
let audioInputCallback: TempiAudioInputCallback = { (numberOfFrames, timeStamp, inout samples: [Float]) -> Void in
self.gotSomeAudio(numberOfFrames, timeStamp: timeStamp, samples: samples)
}
audioInput = TempiAudioInput(audioInputCallback: audioInputCallback, sampleRate: 44100, numberOfChannels: 1)
audioInput.startRecording()
// how can i return the Array from the gotSomeAudio function?
return xyz
}
@objc
public func gotSomeAudio(numberOfFrames: Int, timeStamp: Double, samples: [Float]) -> Array<Float> {
let fft = TempiFFT(withSize: numberOfFrames, sampleRate: 44100)
// Setting a window type reduces errors
fft.windowType = TempiFFTWindowType.hanning
// Perform the FFT
fft.fftForward(samples)
// Map FFT data to logical bands. This gives 4 bands per octave across 7 octaves = 28 bands.
//fft.calculateLogarithmicBands(minFrequency: 100, maxFrequency: 11025, bandsPerOctave: 4)
//fft.calculateLinearBands(minFrequency: 0, maxFrequency: fft.nyquistFrequency, numberOfBands: Int(screenWidth))
fft.calculateLogarithmicBands(minFrequency: 100, maxFrequency: 11025, bandsPerOctave: 4)
// Process some data
return fft.bandFrequencies
}
}
You can pass it to a callback function: 您可以将其传递给回调函数:
public func run(complete: Array<Float> -> Void) {
let audioInputCallback: TempiAudioInputCallback = { (numberOfFrames, timeStamp, inout samples: [Float]) -> Void in
complete(self.gotSomeAudio(numberOfFrames, timeStamp: timeStamp, samples: samples))
}
...
myInstance.run() { floatArray in
// Use floatArray here.
}
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