How to save photos taken using AVFoundation to Photo Album?

Question

AVFoundation is just great for those who want to get hands dirty, but there still a lot of basic stuff not easy to figure like how to save the pictures taken from device to Photo Album

Any ideas?

Answer 1

Here is a step by step tutorial on how to capture an image using AVFoundation and save it to photo album.

Add a UIView object to the NIB (or as a subview), and create a @property in your controller:

@property(nonatomic, retain) IBOutlet UIView *vImagePreview;

Connect the UIView to the outlet above in IB, or assign it directly if you’re using code instead of a NIB.

Then edit your UIViewController, and give it the following viewDidAppear method:

-(void)viewDidAppear:(BOOL)animated
{
    AVCaptureSession *session = [[AVCaptureSession alloc] init];
    session.sessionPreset = AVCaptureSessionPresetMedium;

    CALayer *viewLayer = self.vImagePreview.layer;
    NSLog(@"viewLayer = %@", viewLayer);

    AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

    captureVideoPreviewLayer.frame = self.vImagePreview.bounds;
    [self.vImagePreview.layer addSublayer:captureVideoPreviewLayer];

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    NSError *error = nil;
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
    if (!input) {
        // Handle the error appropriately.
        NSLog(@"ERROR: trying to open camera: %@", error);
    }
    [session addInput:input];

    stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [stillImageOutput setOutputSettings:outputSettings];
    [session addOutput:stillImageOutput];

    [session startRunning];
}

Create a new @property to hold a reference to output object:

@property(nonatomic, retain) AVCaptureStillImageOutput *stillImageOutput;

Then make a UIImageView where we’ll display the captured photo. Add this to your NIB, or programmatically.

Hook it up to another @property, or assign it manually, e.g.;

@property(nonatomic, retain) IBOutlet UIImageView *vImage;

Finally, create a UIButton, so that you can take the photo.

Again, add it to your NIB (or programmatically to your screen), and hook it up to the following method:

-(IBAction)captureNow {
    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);
    [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];
        UIImage *image = [[UIImage alloc] initWithData:imageData];

        self.vImage.image = image;

        UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
     }];
}

You might have to import #import <ImageIO/CGImageProperties.h> also.

Source. Also check this.

Answer 2

According to your question, looks like you've already got the picture from the camera into NSData or UIImage. If so, you can add this picture to the album in differrent ways. AVFoundation itself doesn't have classes which are carrying the holding of the images. So, for example, you can use the ALAssetsLibrary framework to save image to the Photo Album. Or you can use just UIKit framework with it's UIImageWriteToSavedPhotosAlbum method. Both are good to use.

In case that you don't have still image captured yet, you can look at the captureStillImageAsynchronouslyFromConnection method of the AVFoundation framework. Anyway, here are the ideas. You can find examples in the Internet easily. Good luck :)