How to save photos taken using AVFoundation to Photo Album?

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难免孤独
难免孤独 2020-12-23 11:02

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

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  •  梦毁少年i
    2020-12-23 11:34

    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 also.

    Source. Also check this.

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