captureStillImageAsynchronously Issue - ios

Question

I'm currently having an issue with AVCaptureStillImageOutput where when I try to take a picture the image is currently nil. My current attempts at bug fixing have found that captureStillImageAsynchronously method isn't being called at all and I haven't been able to test whether the sample buffer is nil or not. I'm using this method to feed the camera image into another method that combines the camera image and another image into a single image. The thread fails during that last method. When I try to examine the image from the capture method it is unavailable. What do I need to do to get the camera capture working?
public func capturePhotoOutput()->UIImage
{
var image:UIImage = UIImage()
if let videoConnection = stillImageOutput!.connection(withMediaType: AVMediaTypeVideo)
{
print("Video Connection established ---------------------")
stillImageOutput?.captureStillImageAsynchronously(from: videoConnection, completionHandler: {(sampleBuffer, error) in
if (sampleBuffer != nil)
{
print("Sample Buffer not nil ---------------------")
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer)
let dataProvider = CGDataProvider(data: imageData! as CFData)
let cgImageRef = CGImage(jpegDataProviderSource: dataProvider!, decode: nil, shouldInterpolate: true, intent: .defaultIntent)
let camImage = UIImage(cgImage: cgImageRef!, scale: CGFloat(1.0), orientation: UIImageOrientation.right)
image = camImage
}
else
{
print("nil sample buffer ---------------------")
}
})
}
if (stillImageOutput?.isCapturingStillImage)!
{
print("image capture in progress ---------------------")
}
else
{
print("capture not in progress -------------------")
}
return image
}
EDIT: Added below method where the camera image is being used.
func takePicture()-> UIImage
{
/*
videoComponent!.getVideoController().capturePhotoOutput
{ (image) in
//Your code
guard let topImage = image else
{
print("No image")
return
}
}
*/
let topImage = videoComponent!.getVideoController().capturePhotoOutput() //overlay + Camera
let bottomImage = captureTextView() //text
let size = CGSize(width:(topImage.size.width),height:(topImage.size.height)+(bottomImage.size.height))
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
topImage.draw(in: CGRect(x:0, y:0, width:size.width, height: (topImage.size.height)))
bottomImage.draw(in: CGRect(x:(size.width-bottomImage.size.width)/2, y:(topImage.size.height), width: bottomImage.size.width, height: (bottomImage.size.height)))
let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}

Answer 1

If you use async method the function will return a wrong value, because the async call is still in progress. You can use a completion block, like that:
public func capturePhotoOutput(completion: (UIImage?) -> ())
{
if let videoConnection = stillImageOutput!.connection(withMediaType: AVMediaTypeVideo)
{
print("Video Connection established ---------------------")
stillImageOutput?.captureStillImageAsynchronously(from: videoConnection, completionHandler: {(sampleBuffer, error) in
if (sampleBuffer != nil)
{
print("Sample Buffer not nil ---------------------")
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer)
let dataProvider = CGDataProvider(data: imageData! as CFData)
let cgImageRef = CGImage(jpegDataProviderSource: dataProvider!, decode: nil, shouldInterpolate: true, intent: .defaultIntent)
let camImage = UIImage(cgImage: cgImageRef!, scale: CGFloat(1.0), orientation: UIImageOrientation.right)
completion(camImage)
}
else
{
completion(nil)
}
})
}
else
{
completion(nil)
}
}
How to use it:
capturePhotoOutput
{ (image) in
guard let topImage = image else{
print("No image")
return
}
//Your code
}
Edit:
func takePicture()
{
videoComponent!.getVideoController().capturePhotoOutput
{ (image) in
guard let topImage = image else
{
print("No image")
return
}
let bottomImage = self.captureTextView() //text
let size = CGSize(width:(topImage.size.width),height:(topImage.size.height)+(bottomImage.size.height))
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
topImage.draw(in: CGRect(x:0, y:0, width:size.width, height: (topImage.size.height)))
bottomImage.draw(in: CGRect(x:(size.width-bottomImage.size.width)/2, y:(topImage.size.height), width: bottomImage.size.width, height: (bottomImage.size.height)))
let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
self.setPicture(image: newImage)
}
}
func setPicture(image:UIImage)
{
//Your code after takePicture
}