Capture still image from AVCaptureSession in Swift

问题

I have an AVCaptureSession that displays live video in a UIView, and I want to save a frame of the video stream as a UIImage. I've been dissecting the code I keep seeing around the internet, but I'm having trouble with the first line:

if let stillOutput = self.stillImageOutput {
    // Establish an AVCaptureConnection and capture a still image from it.
}

This gives me the error 'Camera' does not have a member named 'stillImageOutput'. The code depends on being able to get the video connection from the output.

I can post the full code block if that'd be helpful. Thanks!

回答1:

Once you have stillImageOutput you can use following methods to capture image

 stillImageOutput.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG]
    if captureSession.canAddOutput(stillImageOutput) {
        captureSession.addOutput(stillImageOutput)
    }

    // I had to add timer otherwise quality was messed up in iPad
    var timer = NSTimer.scheduledTimerWithTimeInterval(0.4, target: self, selector: Selector("getImage"), userInfo: nil, repeats: false)

Than my function to get image

func getImage() {

    if let videoConnection = stillImageOutput.connectionWithMediaType(AVMediaTypeVideo) {
        stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection) {
            (imageDataSampleBuffer, error) -> Void in
            let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)

//          Use your image or store to Album

//          UIImageWriteToSavedPhotosAlbum(UIImage(data: imageData), nil, nil, nil)
            self.stopSession()

        }
    }

}

And to stop session and remove preview layer

func stopSession(){


    self.captureSession.stopRunning()
    self.previewLayer?.removeFromSuperlayer()

}

来源：https://stackoverflow.com/questions/26529787/capture-still-image-from-avcapturesession-in-swift

标签

ios

swift

avcapturesession