Double camera output in iOS - iphone

Question

I want to make twin screen using built-in camera on iOS
I tried following code, but it shows just one view.
It's a natural result, I know.
Here's the code what I used..
- (void)prepareCameraView:(UIView *)window
{
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetMedium;
CALayer *viewLayer = window.layer;
NSLog(#"viewLayer = %#", viewLayer);
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc]
initWithSession:session];
captureVideoPreviewLayer.frame = window.bounds;
[window.layer addSublayer:captureVideoPreviewLayer];
AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
if (!input)
{
NSLog(#"ERROR : trying to open camera : %#", error);
}
[session addInput:input];
[session startRunning];
}
How can I get double screen on iOS?

Answer 1

// Use this code
AVCaptureSession *session = [AVCaptureSession new];
AVCaptureDevice *inputDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error;
AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:inputDevice error:&error];
if ( [session canAddInput:deviceInput])
{
[session addInput:deviceInput];
}
AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[previewLayer setFrame:CGRectMake(0.0, 0.0, self.view.bounds.size.width, self.view.bounds.size.height)];
NSUInteger replicatorInstances = 2;
CGFloat replicatorViewHeight = (self.view.bounds.size.height - 64)/replicatorInstances;
CAReplicatorLayer *replicatorLayer = [CAReplicatorLayer layer];
replicatorLayer.frame = CGRectMake(0, 0.0, self.view.bounds.size.width, replicatorViewHeight);
replicatorLayer.instanceCount = replicatorInstances;
replicatorLayer.instanceTransform = CATransform3DMakeTranslation(0.0, replicatorViewHeight, 0.0);
[replicatorLayer addSublayer:previewLayer];
[self.view.layer addSublayer:replicatorLayer];
[session startRunning];

Answer 2

Try this:
- (void)prepareCameraView:(UIView *)window
{
NSArray *captureDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
{
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetMedium;
CALayer *viewLayer = window.layer;
NSLog(#"viewLayer = %#", viewLayer);
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = CGRectMake(0.0f, 0.0f, window.bounds.size.width/2.0f, window.bounds.size.height);
[window.layer addSublayer:captureVideoPreviewLayer];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:[captureDevices objectAtIndex:0] error:&error];
if (!input)
{
NSLog(#"ERROR : trying to open camera : %#", error);
}
[session addInput:input];
[session startRunning];
}
{
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetMedium;
CALayer *viewLayer = window.layer;
NSLog(#"viewLayer = %#", viewLayer);
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = CGRectMake(window.bounds.size.width/2.0f, 0.0f, window.bounds.size.width/2.0f, window.bounds.size.height);
[window.layer addSublayer:captureVideoPreviewLayer];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:[captureDevices objectAtIndex:1] error:&error];
if (!input)
{
NSLog(#"ERROR : trying to open camera : %#", error);
}
[session addInput:input];
[session startRunning];
}
}
Note that it makes absolutely no checks that there are actually 2 cameras and it splits it vertically so this is probably best viewed in landscape. You'll want to add some checks into that code and work out exactly how you want to lay out the layers of each camera before using it.