iOS demo app.

examples/ios_demo_apps/ExecuTorchDemo/ExecuTorchDemo/Sources/App/App.swift

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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import SwiftUI
+
+@main
+struct App: SwiftUI.App {
+  var body: some Scene {
+    WindowGroup {
+      ContentView()
+    }
+  }
+}

examples/ios_demo_apps/ExecuTorchDemo/ExecuTorchDemo/Sources/App/CameraController.swift

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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import AVFoundation
+import SwiftUI
+
+enum CameraControllerError: Error {
+  case authorization(String)
+  case capture(String)
+  case setup(String)
+}
+
+class CameraController: NSObject, ObservableObject, AVCapturePhotoCaptureDelegate {
+  let captureSession = AVCaptureSession()
+  private var photoOutput = AVCapturePhotoOutput()
+  private var timer: Timer?
+  private var callback: ((Result<UIImage, Error>) -> Void)?
+
+  func startCapturing(withTimeInterval interval: TimeInterval,
+                      callback: @escaping (Result<UIImage, Error>) -> Void) {
+    authorize { error in
+      if let error {
+        DispatchQueue.main.async {
+          callback(.failure(error))
+        }
+        return
+      }
+      self.setup { error in
+        if let error {
+          DispatchQueue.main.async {
+            callback(.failure(error))
+          }
+          return
+        }
+        self.captureSession.startRunning()
+        DispatchQueue.main.async {
+          self.callback = callback
+          self.timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) { _ in
+            self.photoOutput.capturePhoto(with: AVCapturePhotoSettings(), delegate: self)
+          }
+        }
+      }
+    }
+  }
+
+  private func authorize(_ completion: @escaping (Error?) -> Void) {
+    switch AVCaptureDevice.authorizationStatus(for: .video) {
+    case .authorized:
+      DispatchQueue.global(qos: .userInitiated).async {
+        completion(nil)
+      }
+    case .notDetermined:
+      AVCaptureDevice.requestAccess(for: .video) { granted in
+        DispatchQueue.global(qos: .userInitiated).async {
+          if granted {
+            completion(nil)
+          } else {
+            completion(CameraControllerError.authorization("Camera access denied"))
+          }
+        }
+      }
+    default:
+      DispatchQueue.global(qos: .userInitiated).async {
+        completion(CameraControllerError.authorization("Camera access denied"))
+      }
+    }
+  }
+
+  private func setup(_ callback: (Error?) -> Void) {
+    guard let videoCaptureDevice = AVCaptureDevice.default(for: .video)
+    else {
+      callback(CameraControllerError.setup("Cannot get video capture device"))
+      return
+    }
+    let videoInput: AVCaptureDeviceInput
+    do {
+      videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
+    } catch {
+      callback(CameraControllerError.setup("Cannot set up video input: \(error)"))
+      return
+    }
+    if captureSession.canAddInput(videoInput) {
+      captureSession.addInput(videoInput)
+    } else {
+      callback(CameraControllerError.setup("Cannot add video input"))
+      return
+    }
+    if captureSession.canAddOutput(photoOutput) {
+      captureSession.addOutput(photoOutput)
+    } else {
+      callback(CameraControllerError.setup("Cannot add photo output"))
+      return
+    }
+    callback(nil)
+  }
+
+  func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
+    guard let callback = self.callback else {
+      print("No image capturing callback set")
+      return
+    }
+    if let error {
+      callback(.failure(CameraControllerError.capture("Image capture error: \(error)")))
+    }
+    guard let imageData = photo.fileDataRepresentation(),
+          let image = UIImage(data: imageData),
+          let cgImage = image.cgImage
+    else {
+      callback(.failure(CameraControllerError.capture("Couldn't get image data")))
+      return
+    }
+    var orientation = UIImage.Orientation.up
+    switch UIDevice.current.orientation {
+    case .portrait:
+      orientation = .right
+    case .portraitUpsideDown:
+      orientation = .left
+    case .landscapeRight:
+      orientation = .down
+    default:
+      break
+    }
+    callback(.success(UIImage(cgImage: cgImage, scale: image.scale, orientation: orientation)))
+  }
+}

examples/ios_demo_apps/ExecuTorchDemo/ExecuTorchDemo/Sources/App/CameraPreview.swift

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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import AVFoundation
+import SwiftUI
+
+struct CameraPreview: UIViewRepresentable {
+  let captureSession: AVCaptureSession
+
+  func makeUIView(context: Context) -> UIView {
+    let view = CameraView(frame: UIScreen.main.bounds)
+    view.videoPreviewLayer?.session = captureSession
+    return view
+  }
+
+  func updateUIView(_ uiView: UIView, context: Context) {
+    if let view = uiView as? CameraView {
+      view.videoPreviewLayer?.frame = uiView.bounds
+    }
+  }
+}
+
+final class CameraView: UIView {
+  override class var layerClass: AnyClass {
+    return AVCaptureVideoPreviewLayer.self
+  }
+
+  var videoPreviewLayer: AVCaptureVideoPreviewLayer? {
+    return layer as? AVCaptureVideoPreviewLayer
+  }
+}

examples/ios_demo_apps/ExecuTorchDemo/ExecuTorchDemo/Sources/App/ClassificationController.swift

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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import ImageClassification
+import MobileNetClassifier
+import SwiftUI
+
+enum Mode: String, CaseIterable {
+  case xnnpack = "XNNPACK"
+  case benchmark = "Benchmark"
+  case coreML = "Core ML"
+}
+
+class ClassificationController: ObservableObject {
+  @AppStorage("mode") var mode: Mode = .benchmark
+  @Published var classifications: [Classification] = []
+  @Published var elapsedTime: TimeInterval = 0.0
+  @Published var isRunning = false
+
+  private let queue = DispatchQueue(label: "org.pytorch.executorch.demo", qos: .userInitiated)
+  private var classifier: ImageClassification?
+  private var currentMode: Mode = .benchmark
+
+  func classify(_ image: UIImage) {
+    guard !isRunning else {
+      print("Dropping frame")
+      return
+    }
+    isRunning = true
+
+    if currentMode != mode {
+      currentMode = mode
+      classifier = nil
+    }
+    queue.async {
+      var classifications: [Classification] = []
+      var elapsedTime: TimeInterval = -1
+      do {
+        if self.classifier == nil {
+          self.classifier = try self.createClassifier(for: self.currentMode)
+        }
+        let startTime = CFAbsoluteTimeGetCurrent()
+        classifications = try self.classifier?.classify(image: image) ?? []
+        elapsedTime = (CFAbsoluteTimeGetCurrent() - startTime) * 1000
+      } catch {
+        print("Error classifying image: \(error)")
+      }
+      DispatchQueue.main.async {
+        self.classifications = classifications
+        self.elapsedTime = elapsedTime
+        self.isRunning = false
+      }
+    }
+  }
+
+  private func createClassifier(for mode: Mode) throws -> ImageClassification? {
+    let modelFileName: String
+    switch mode {
+    case .xnnpack:
+      modelFileName = "mv3_xnnpack_fp32"
+    case .benchmark:
+      modelFileName = "mv3"
+    case .coreML:
+      modelFileName = "mv3_coreml"
+    }
+    guard let modelFilePath = Bundle.main.path(forResource: modelFileName, ofType: "pte"),
+          let labelsFilePath = Bundle.main.path(forResource: "imagenet_classes", ofType: "txt")
+    else { return nil }
+    return try MobileNetClassifier(modelFilePath: modelFilePath, labelsFilePath: labelsFilePath)
+  }
+}

examples/ios_demo_apps/ExecuTorchDemo/ExecuTorchDemo/Sources/App/ContentView.swift

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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import AVFoundation
+import SwiftUI
+
+struct ContentView: View {
+  @StateObject private var cameraController = CameraController()
+  @StateObject private var classificationController = ClassificationController()
+
+  var body: some View {
+    ZStack {
+      cameraPreview
+      controlPanel
+    }
+  }
+
+  private var cameraPreview: some View {
+    CameraPreview(captureSession: cameraController.captureSession)
+      .aspectRatio(contentMode: .fill)
+      .edgesIgnoringSafeArea(.all)
+      .onAppear(perform: startCapturing)
+      .onDisappear(perform: stopCapturing)
+  }
+
+  private var controlPanel: some View {
+    VStack(spacing: 0) {
+      TopBar(title: "ExecuTorch Demo")
+      ClassificationLabelView(controller: classificationController)
+      Spacer()
+      ClassificationTimeView(controller: classificationController)
+      ModeSelector(controller: classificationController)
+    }
+  }
+
+  private func startCapturing() {
+    UIApplication.shared.isIdleTimerDisabled = true
+    cameraController.startCapturing(withTimeInterval: 1.0) { result in
+      switch result {
+      case .success(let image):
+        self.classificationController.classify(image)
+      case .failure(let error):
+        self.handleError(error)
+      }
+    }
+  }
+
+  private func stopCapturing() {
+    UIApplication.shared.isIdleTimerDisabled = false
+  }
+
+  private func handleError(_ error: Error) {
+    stopCapturing()
+    print(error)
+  }
+}
+
+struct ContentView_Previews: PreviewProvider {
+  static var previews: some View {
+    ContentView()
+  }
+}