Question

i am new to AVFoundation and i am trying to implement a video camera with AVFoundation here is my basic setup. Basically, when you click a button it will call the showCamera method. In here i create the session and then add an audio input and video input then add the video output.

Where in here do i add the AVCaptureConnection and how do i do it? Is there some tutorial that shows how to use the connections? Any help is appreciated.

- (IBAction) showCamera
{
//Add the camview to the current view ontop of controller
[[[[[UIApplication sharedApplication] delegate] self] window] addSubview:camView];

session = [[AVCaptureSession alloc] init];

//Set preset on session to make recording scale high
if ([session canSetSessionPreset:AVCaptureSessionPresetHigh]) {
    session.sessionPreset = AVCaptureSessionPresetHigh;
}

// Add inputs and outputs.
NSArray *devices = [AVCaptureDevice devices];

//Print out all devices on phone
for (AVCaptureDevice *device in devices) 
{

    if ([device hasMediaType:AVMediaTypeVideo]) 
    {

        if ([device position] == AVCaptureDevicePositionBack) 
        {

            //Add Rear Video input to session
            [self addRearCameraInputToSession:session withDevice:device];

        }


    } 
    else if ([device hasMediaType:AVMediaTypeAudio]) 
    {

        //Add Microphone input to session
        [self addMicrophoneInputToSession:session withDevice:device];
    }
    else
    {
        //Show error that your camera does not have a phone
    }
}



//Add movie output
[self addMovieOutputToSession:session];

//Construct preview layer
[self constructPreviewLayerWithSession:session onView:camView];

}

Answer 1

You don’t add AVCaptureConnections manually. When you have both an input and an output added to the AVCaptureSession object, the connections are automatically created for you. Quoth the documentation:

When an input or an output is added to a session, the session greedily forms connections between all the compatible capture inputs’ ports and capture outputs.

Unless you need to disable one of the automatically-created connections, or change the videoMirrored or videoOrientation properties, you shouldn’t have to worry about them at all.