SwiftUI Capture

Taking a picture or recording a video has never been that easy.

SwiftUI makes UI development more efficient. Although PhotosPicker brings access to the Photo Library to SwiftUI, the framework was still lacking the tool to manipulate the camera. This package intends to make it easy to use AVCaptureSession from SwiftUI to take pictures or record videos (supporting custom audio/video settings).

Example

Taking a picture 📸

import Capture

struct ContentView: View {
    @State private var outputPhoto: UIImage?
    var body: some View {
        CameraView(outputImage: $outputPhoto) { authorizationStatus in
            if case .authorized = authorizationStatus { 
                TakePictureOverlay()
            }
        }
    }
}

struct TakePictureOverlay: View {
    @Environment(\.takePicture) var takePicture

    var body: some View {
        Button(action: { takePicture() }) {
            Text("Take a picture")
        }
    }
}

Recording a video 🎬

struct ContentView: View {
    @State private var outputFile: URL?
    var body: some View {
        CameraView(outputVideo: $outputFile) { authorizationStatus in
            if case .authorized = autorizationStatus {
                RecordVideoOverlay()
            }
        }
    }
}

struct RecordVideoOverlay: View {
    @Environment(\.recordVideo) private var recordVideo
    @State private var isRecording: Bool = false

    var body: some View {
        Button(action: { toggleRecording() }) {
            Image(systemName: isRecording ? "stop.circle" : "record.circle")
        }
    }
    
    func toggleRecording() {
        if isRecording {
            recordVideo.stopRecording()
        } else {
            recordVideo.startRecording()
        }
        isRecording.toggle()
    }
}

Interface

CameraView

CameraView takes the minimum number of parameters to provide the most :

• camera: an optional camera object, with a default value set to Camera.default. This parameter is only useful to bring control over the camera object outside the camera overlay.

• outputImage: an optional binding to an image if the camera view is used to take a picture

• outputVideo: an optional binding to a file URL if the camera view is used to record video

Both outputImage and outputVideo can be used together if the camera view needs to perform both actions. None can be used if only the camera preview is necessary.

• options: a few options that are described below.

• overlay: a View Builder closure to build a camera overlay that may vary according to the current camera authorization. CameraView will automatically request the camera authorization for video when appearing. This behavior can be modified by setting the option automaticallyRequestsAuthorization to false, if the camera authorization should be handled separately.

Environment Values

Provides two actions through environment values available to the Camera Overlay

• @Environment(.takePicture) will take a picture and output it to outputImage.

• @Environment(.recordVideo) exposes the two following methods: startRecording() and stopRecording(). When stopped, the recorded video will be saved and the temporary file URL output to outputVideo.

• @EnvironmentObject var camera: Camera is also available to access fine control over the preview stream (resume/pause the preview) or the camera devices.

Default behaviors

CameraView automatically starts or resumes the AVCaptureSession when the view appears, and automatically stops it when the view disappears. This behavior can be modified by setting the option automaticallyRequestsAuthorization to false.

When taking a picture, CameraView triggers a visual feedback, this behavior can be disabled by settings the option isTakePictureFeedbackEnabled to false.

Under the hood

AVCaptureVideoPreviewLayer is used for the video output

It seems that AVCaptureVideoPreviewLayer is still more efficient than passing Image(cvImageBuffer: CVImageBuffer) to SwiftUI from an AsyncStream, which you can see in use in this example from Apple.

Coming soon...

• Support for Flash, Torch, Focus & Exposure
• Support for custom photo settings