I have a preview layer that is pulling from the camera and working as it should. I would like to be able to take a picture when I press a button. I have inited the AVCaptureStil
for swift version:
@IBAction func capture(sender: AnyObject) {
var videoConnection :AVCaptureConnection?
if let videoConnection = stillImageOutput.connectionWithMediaType(AVMediaTypeVideo){
stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: { (buffer:CMSampleBuffer!, error: NSError!) -> Void in
if let exifAttachments = CMGetAttachment(buffer, kCGImagePropertyExifDictionary, nil) {
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
self.previewImage.image = UIImage(data: imageData)
UIImageWriteToSavedPhotosAlbum(self.previewImage.image, nil, nil, nil)
}
})
}
}
-(void)captureImage:(NSString *)string successCallback:(void (^)(id))successCallback errorCallback:(void (^)(NSString *))errorCallback{
__block UIImage *image;
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in stillImageOutput.connections)
{
for (AVCaptureInputPort *port in [connection inputPorts])
{
if ([[port mediaType] isEqual:AVMediaTypeVideo] )
{
videoConnection = connection;
break;
}
}
if (videoConnection)
{
break;
}
}
//NSLog(@"about to request a capture from: %@", stillImageOutput);
[videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
{
CFDictionaryRef exifAttachments = CMGetAttachment( imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments)
{
// Do something with the attachments.
//NSLog(@"attachements: %@", exifAttachments);
} else {
//NSLog(@"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
image = [[UIImage alloc] initWithData:imageData];
successCallback(image);
//UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
}];
NSError *error;
if (error) {
errorCallback(@"error");
}else{
}
}
You need to be sure to define a AVCaptureVideoPreviewLayer & add it to a view layer :
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[self.view.layer addSublayer:captureVideoPreviewLayer];
This will be connected to your AVCaptureDeviceInput
Here's the full solution :
/////////////////////////////////////////////////
////
//// Utility to find front camera
////
/////////////////////////////////////////////////
-(AVCaptureDevice *) frontFacingCameraIfAvailable{
NSArray *videoDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
AVCaptureDevice *captureDevice = nil;
for (AVCaptureDevice *device in videoDevices){
if (device.position == AVCaptureDevicePositionFront){
captureDevice = device;
break;
}
}
// couldn't find one on the front, so just get the default video device.
if (!captureDevice){
captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
}
return captureDevice;
}
/////////////////////////////////////////////////
////
//// Setup Session, attach Video Preview Layer
//// and Capture Device, start running session
////
/////////////////////////////////////////////////
-(void) setupCaptureSession {
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetMedium;
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[self.view.layer addSublayer:captureVideoPreviewLayer];
NSError *error = nil;
AVCaptureDevice *device = [self frontFacingCameraIfAvailable];
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
// Handle the error appropriately.
NSLog(@"ERROR: trying to open camera: %@", error);
}
[session addInput:input];
self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:outputSettings];
[session addOutput:self.stillImageOutput];
[session startRunning];
}
/////////////////////////////////////////////////
////
//// Method to capture Still Image from
//// Video Preview Layer
////
/////////////////////////////////////////////////
-(void) captureNow {
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in self.stillImageOutput.connections) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) { break; }
}
NSLog(@"about to request a capture from: %@", self.stillImageOutput);
__weak typeof(self) weakSelf = self;
[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[weakSelf displayImage:image];
}];
}
Not sure why I didn't see this sooner:
iPhone SDK 4 AVFoundation - How to use captureStillImageAsynchronouslyFromConnection correctly?
Adams answer works fantastic!