I'm trying to implement barcode scanning in my iOS app, but for some reason I can't open the camera. I'm using Apple's AVFoundation framework for scanning.
This is my code for launching the camera and implement the scanner:
// Get the back-facing camera for capturing videos
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .back)
guard let captureDevice = deviceDiscoverySession.devices.first else {
print("Failed to get the camera device")
return
}
do {
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
let input = try AVCaptureDeviceInput(device: captureDevice)
// Set the input device on the capture session.
captureSession?.addInput(input)
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
// Set delegate and use the default dispatch queue to execute the call back
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
captureMetadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.qr]
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
// Start video capture.
captureSession?.startRunning()
// Initialize QR Code Frame to highlight the QR code
qrCodeFrameView = UIView()
if let qrCodeFrameView = qrCodeFrameView {
qrCodeFrameView.layer.borderColor = UIColor.green.cgColor
qrCodeFrameView.layer.borderWidth = 2
view.addSubview(qrCodeFrameView)
view.bringSubview(toFront: qrCodeFrameView)
}
} catch {
// If any error occurs, simply print it out and don't continue any more.
print(error)
return
}
Immediately as the screen loads, I get the following message printed to the console:
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[AVCaptureMetadataOutput setMetadataObjectTypes:] Unsupported type found - use -availableMetadataObjectTypes'
*** First throw call stack:
(0x1824d2d8c 0x18168c5ec 0x18803eb44 0x1013f035c 0x1013f12ec 0x18c23e64c 0x18c35f870 0x18c244700 0x18c37a1a8 0x18c2c19e0 0x18c2b6890 0x18c2b51d0 0x18ca96d1c 0x18ca992c8 0x18ca92368 0x18247b404 0x18247ac2c 0x18247879c 0x182398da8 0x18437d020 0x18c3b5758 0x1013da1d8 0x181e29fc0)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
I couldn't find any solution on Stack Overflow or on any other website.
Could you please help me fixing this?
So I had the same error and I solved it by making small changes. Hope this helps(if you haven't resolved it already!).
let input = try AVCaptureDeviceInput(device: captureDevice)
//Make sure you have initialized the captureSession object
captureSession = AVCaptureSession()
captureSession?.addInput(input)
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
// Main Change
captureMetadataOutput.metadataObjectTypes = captureMetadataOutput.availableMetadataObjectTypes
//[AVMetadataObject.ObjectType.qr]
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
captureSession?.startRunning()
Related
I'm developing a QR and Matrix Code reader app. I'm getting AVCaptureDeviceInput with AvCaptureDevice.DiscoverySession. My problem is that It is only available after iOS 10.0. How can I get it for fallback versions?
// Get the back-facing camera for capturing videos
if #available(iOS 10.0, *) {
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .back)
guard let captureDevice = deviceDiscoverySession.devices.first else {
print("Failed to get the camera device")
return
}
} else {
// Fallback on earlier versions
}
do {
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
let input = try AVCaptureDeviceInput(device: captureDevice)
// Set the input device on the capture session.
captureSession.addInput(input)
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession.addOutput(captureMetadataOutput)
// Set delegate and use the default dispatch queue to execute the call back
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
//TODO: Decide the data types!
captureMetadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.dataMatrix]
//captureMetadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.qr]
} catch {
// If any error occurs, simply print it out and don't continue any more.
print(error)
return
}
If you want to get list of AVCaptureDevice, you can use
let cameras = AVCaptureDevice.devices(for: AVMediaType.video)
in iOS 9
hello i had a working code with AVCaptureVideoPreviewLayer.. it's a part barcode reader:
let captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
do {
let input = try AVCaptureDeviceInput(device: captureDevice) as AVCaptureDeviceInput
session.addInput(input)
print("input done..")
} catch let error as NSError {
print(error)
}
let output = AVCaptureMetadataOutput()
output.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
session.addOutput(output)
output.metadataObjectTypes = output.availableMetadataObjectTypes
previewLayer = AVCaptureVideoPreviewLayer(session: session) as AVCaptureVideoPreviewLayer
previewLayer.frame = self.view.bounds
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
self.view.layer.addSublayer(previewLayer)
self.view.bringSubviewToFront(self.highlightView)
session.startRunning()
It was starting and running also, there wasn't any error messeage and i used on my old iPhone too and i could see the picture of the camera. But 2 days ago my iphone's been replaced, i didn't change anything in the code. Now the app starting but i can see only black screen.
Does anybody know what could cause this?
Thank you!
This is the code I used to test this out:
override func viewDidLoad() {
super.viewDidLoad()
var session = AVCaptureSession.new()
session.sessionPreset = AVCaptureSessionPresetMedium
let captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
let input = AVCaptureDeviceInput(device: captureDevice, error: nil) as AVCaptureDeviceInput
session.addInput(input)
print("input done..")
var previewLayer = AVCaptureVideoPreviewLayer(session: session) as AVCaptureVideoPreviewLayer
previewLayer.frame = self.view.bounds
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
self.view.layer.addSublayer(previewLayer)
session.startRunning()
}
I appears that the problem was that you did not pass in the NSError required by the AVCaptureDeviceInput. Xcode was not sure what the try statement was trying to do as well. I've simply passed in nil into the constructor for now, but you will want to make sure that you handle it. I also removed the part on setting up the output, as that was not relevant to my testing. Feel free to add that back in.
I tested this on my iPhone 4 running iOS 7.1 for reference.
From iOS 8 you need to ask for the permission, you can do something like this
if ([AVCaptureDevice respondsToSelector:#selector(requestAccessForMediaType: completionHandler:)]) {
[AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
if (granted) {
// Got the permission
} else {
// Permission has been denied.
}
}];
} else {
// below ios 6
}
you can execute permission method in swifth
if AVCaptureDevice.respondsToSelector(Selector("requestAccessForMediaType"))
{
AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { (grandted:Bool) -> Void in
//Check if granted and if its true do camera work else permission denied
})
}
else
{
// Below iOS 6
}
i'm updating my app to Swift 2 with Xcode 7. this is my code of a ViewController viewDidLoad.
override func viewDidLoad() {
super.viewDidLoad()
// Get an instance of the AVCaptureDevice class to initialize a device object and provide the video
// as the media type parameter.
let captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
var error:NSError?
let input: AnyObject! = AVCaptureDeviceInput.deviceInputWithDevice(captureDevice, error: &error)
if (error != nil) {
// If any error occurs, simply log the description of it and don't continue any more.
print("\(error?.localizedDescription)")
return
}
// Initialize the captureSession object.
captureSession = AVCaptureSession()
// Set the input device on the capture session.
captureSession?.addInput(input as! AVCaptureInput)
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
// Set delegate and use the default dispatch queue to execute the call back
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
captureMetadataOutput.metadataObjectTypes = supportedBarCodes
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
// Start video capture.
captureSession?.startRunning()
// Move the message label to the top view
view.bringSubviewToFront(messageLabel)
// Initialize QR Code Frame to highlight the QR code
qrCodeFrameView = UIView()
qrCodeFrameView?.layer.borderColor = UIColor.greenColor().CGColor
qrCodeFrameView?.layer.borderWidth = 2
view.addSubview(qrCodeFrameView!)
view.bringSubviewToFront(qrCodeFrameView!)
}
on line
let input: AnyObject! = AVCaptureDeviceInput.deviceInputWithDevice(captureDevice, error: &error)
i get the error Extra argument error in call. I already tried with the method do{} and catch{} but it didn't work, i always get that error.
How can i fix that? Thanks
Swift 2 introduced new error handling. To solve the problem you are having, you need to catch the error instead of passing an NSError object to the AVCaptureDevice method:
override func viewDidLoad() {
super.viewDidLoad()
do {
let captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
let input = try AVCaptureDeviceInput(device: captureDevice)
// Do the rest of your work...
} catch let error as NSError {
// Handle any errors
print(error)
}
}
For a more in-depth explanation have a look at this article:
Error Handling in Swift 2.0
it doesn't look like that type method exists anymore on AVCaptureDeviceInput, see -> https://developer.apple.com/library/prerelease/ios/documentation/AVFoundation/Reference/AVCaptureDeviceInput_Class/index.html#//apple_ref/swift/cl/c:objc(cs)AVCaptureDeviceInput
(it looks like you probably want to use init(device:))
...as a handy tip: anytime you're browsing the developer library via the web, if you're not sure if you're seeing the latest 'prerelease' version of the documentation check the URL -> add '/prerelease' between 'library' and '/ios' if necessary :)
I got a barcode reader that correctly initialize the first time the view is loaded. However when I go back to the view the video feed stops working.
The code below shows how is initialized in the viewDidLoad method. Any suggestion on how to modify it so I can call part of it when the viewWillAppear (again)?
Code:
override func viewDidLoad() {
super.viewDidLoad()
// Get an instance of the AVCaptureDevice class to initialize a device object and provide the video
// as the media type parameter.
let captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
var error:NSError?
let input: AnyObject! = AVCaptureDeviceInput.deviceInputWithDevice(captureDevice, error: &error)
if (error != nil) {
// If any error occurs, simply log the description of it and don't continue any more.
println("\(error?.localizedDescription)")
return
}
// Initialize the captureSession object.
captureSession = AVCaptureSession()
// Set the input device on the capture session.
captureSession?.addInput(input as AVCaptureInput)
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
// Set delegate and use the default dispatch queue to execute the call back
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
captureMetadataOutput.metadataObjectTypes = supportedBarCodes
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
//videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
var tmpbounds=view.layer.bounds;
videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill;
videoPreviewLayer?.bounds = tmpbounds
videoPreviewLayer?.position = CGPointMake(CGRectGetMidX(tmpbounds), CGRectGetMidY(tmpbounds))
// videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspect
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer)
// Start video capture.
captureSession?.startRunning()
// Move the message label to the top view
view.bringSubviewToFront(messageLabel)
// Initialize QR Code Frame to highlight the QR code
qrCodeFrameView = UIView()
qrCodeFrameView?.layer.borderColor = UIColor.greenColor().CGColor
qrCodeFrameView?.layer.borderWidth = 2
view.addSubview(qrCodeFrameView!)
view.bringSubviewToFront(qrCodeFrameView!)
}
try to execute on viewDidAppear
captureSession?.startRunning()
on viewWillDissapear
captureSession?.stopRunning()
Also register for notification AVCaptureSessionRuntimeErrorNotification and log all errors. I think it will help you to understand what going wrong.
You are setting up the captureSession and the videoPreviewLayer in viewDidLoad. That is only run when the ViewController is created. You need to move some code to viewDidAppear, which will run each time this view appears. Most simply, move all the code from this line:
captureSession = AVCaptureSession()
onwards into viewDidAppear.
I am trying to develop an augmented reality app using swift and scenekit on ios. Is there a way to draw the video captured by the device camera as a background of the scene?
This worked for me,
I used AVFoundation to capture the video input of the device camera:
let captureSession = AVCaptureSession()
let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
if let videoDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo) {
var err: NSError? = nil
if let videoIn : AVCaptureDeviceInput = AVCaptureDeviceInput.deviceInputWithDevice(videoDevice, error: &err) as? AVCaptureDeviceInput {
if(err == nil){
if (captureSession.canAddInput(videoIn as AVCaptureInput)){
captureSession.addInput(videoIn as AVCaptureDeviceInput)
}
else {
println("Failed to add video input.")
}
}
else {
println("Failed to create video input.")
}
}
else {
println("Failed to create video capture device.")
}
}
captureSession.startRunning()
At this point, based on Apple's documentation of the background property of SCNScene, I expected to add the instance of AVCaptureVideoPreviewLayer to an SCNScene's background.contents, with something like:
previewLayer.frame = sceneView.bounds
sceneView.scene.background.contents = previewLayer
This changed the background color of my scene from default white to black, but offered no video input. This may be an iOS bug?.
So Plan B. Instead, I added the 'AVCaptureVideoPreviewLayer' as a sublayer of a UIView's layer:
previewLayer.frame = self.view.bounds
self.view.layer.addSublayer(previewLayer)
I then set an SCNView as a subview of that same UIView, setting the SCNView's background color to clear:
let sceneView = SCNView()
sceneView.frame = self.view.bounds
sceneView.backgroundColor = UIColor.clearColor()
self.view.addSubview(sceneView)
The device camera's video is now visible as the background of the scene.
I've created a small demo.
As of iOS 11, you can now use an AVCaptureDevice as a material on an object or the scene's background (see "Using Animated Content" here)
Example:
let captureDevice = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back)!
scnScene.background.contents = captureDevice
Yes, you can use a AVCaptureVideoPreviewLayer as the contents of a material property (just make sure that you give the layer a bounds).
The scene view has a material property for the background that you can assign the video preview to (assign the layer to the background's contents).
var background: SCNMaterialProperty! { get }