How to perform a method in a continuous method from a delegate every few seconds?-CodePudding

I want to perform something using the AVCaptureVideoDataOutputSampleBufferDelegate protocol. But since it captures every frame at (I think) 30 frames per second, it performs the method 30 times in 1 second and I don't want that. What I want to do is only to perform the method for let's say every 1 second at a time. So far my code looks like this:

func captureOutput(_ output: AVCaptureOutput,
                   didOutput sampleBuffer: CMSampleBuffer,
                   from connection: AVCaptureConnection) {
    // ... perform something
    // ... wait for a second
    // ... perform it again
    // ... wait for another second
    // ... and so on
}

How can I manage to do this?

CodePudding user response：

You can use Timer for that.

Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { timer in
    let randomNumber = Int.random(in: 1...20)
    print("Number: \(randomNumber)")

    if randomNumber == 10 {
        timer.invalidate()
    }
}

CodePudding user response：

You can add a counter and only perform your code every n steps, like eg when you want to perform your code every 30 times the function is called:

var counter: Int = 0

...

func captureOutput(_ output: AVCaptureOutput,
                   didOutput sampleBuffer: CMSampleBuffer,
                   from connection: AVCaptureConnection) {
    if counter0 == 0 {
        // perform your code
    }
    counter  = 1
}