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Add scan flow MVP and local Axiom skill workspace

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This snapshot establishes the camera-to-result recognition flow and related tests while checking in the project skill/docs assets required for the configured local tooling.
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Matthias
2026-04-19 21:11:32 +02:00
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.claude/skills/axiom-camera-capture/.openskills.json Normal file
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{
"source": "CharlesWiltgen/Axiom",
"sourceType": "git",
"repoUrl": "https://github.com/CharlesWiltgen/Axiom",
"subpath": "axiom-codex/skills/axiom-camera-capture",
"installedAt": "2026-04-12T08:05:58.892Z"
}

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---
name: axiom-camera-capture
description: AVCaptureSession, camera preview, photo capture, video recording, RotationCoordinator, session interruptions, deferred processing, capture responsiveness, zero-shutter-lag, photoQualityPrioritization, front camera mirroring
license: MIT
compatibility: iOS 17+, iPadOS 17+, macOS 14+, tvOS 17+, axiom-visionOS 1+
metadata:
version: "1.0.0"
last-updated: "2026-01-03"
---
# Camera Capture with AVFoundation
Guides you through implementing camera capture: session setup, photo capture, video recording, responsive capture UX, rotation handling, and session lifecycle management.
## When to Use This Skill
Use when you need to:
- ☑ Build a custom camera UI (not system picker)
- ☑ Capture photos with quality/speed tradeoffs
- ☑ Record video with audio
- ☑ Handle device rotation correctly (RotationCoordinator)
- ☑ Make capture feel responsive (zero-shutter-lag)
- ☑ Handle session interruptions (phone calls, multitasking)
- ☑ Switch between front/back cameras
- ☑ Configure capture quality and resolution
## Example Prompts
"How do I set up a camera preview in SwiftUI?"
"My camera freezes when I get a phone call"
"The photo preview is rotated wrong on front camera"
"How do I make photo capture feel instant?"
"Should I use deferred processing?"
"My camera takes too long to capture"
"How do I switch between front and back cameras?"
"How do I record video with audio?"
## Red Flags
Signs you're making this harder than it needs to be:
- ❌ Calling `startRunning()` on main thread (blocks UI for seconds)
- ❌ Using deprecated `videoOrientation` instead of RotationCoordinator (iOS 17+)
- ❌ Not observing session interruptions (app freezes on phone call)
- ❌ Creating new AVCaptureSession for each capture (expensive)
- ❌ Using `.photo` preset for video (wrong format)
- ❌ Ignoring `photoQualityPrioritization` (slow captures)
- ❌ Not handling `.notAuthorized` permission state
- ❌ Modifying session without `beginConfiguration()`/`commitConfiguration()`
- ❌ Using UIImagePickerController for custom camera UI (limited control)
## Mandatory First Steps
Before implementing any camera feature:
### 1. Choose Your Capture Mode
```
What do you need?
┌─ Just let user pick a photo?
│ └─ Don't use AVFoundation - use PHPicker or PhotosPicker
│ See: /skill axiom-photo-library
│
├─ Simple photo/video capture with system UI?
│ └─ UIImagePickerController (but limited customization)
│
├─ Custom camera UI with photo capture?
│ └─ AVCaptureSession + AVCapturePhotoOutput
│ → Continue with this skill
│
├─ Custom camera UI with video recording?
│ └─ AVCaptureSession + AVCaptureMovieFileOutput
│ → Continue with this skill
│
└─ Both photo and video in same session?
└─ AVCaptureSession + both outputs
→ Continue with this skill
```
### 2. Request Camera Permission
```swift
import AVFoundation
func requestCameraAccess() async -> Bool {
let status = AVCaptureDevice.authorizationStatus(for: .video)
switch status {
case .authorized:
return true
case .notDetermined:
return await AVCaptureDevice.requestAccess(for: .video)
case .denied, .restricted:
// Show settings prompt
return false
@unknown default:
return false
}
}
```
**Info.plist required**:
```xml
<key>NSCameraUsageDescription</key>
<string>Take photos and videos</string>
```
For audio (video recording):
```xml
<key>NSMicrophoneUsageDescription</key>
<string>Record audio with video</string>
```
### 3. Understand Session Architecture
```
AVCaptureSession
├─ Inputs
│ ├─ AVCaptureDeviceInput (camera)
│ └─ AVCaptureDeviceInput (microphone, for video)
│
├─ Outputs
│ ├─ AVCapturePhotoOutput (photos)
│ ├─ AVCaptureMovieFileOutput (video files)
│ └─ AVCaptureVideoDataOutput (raw frames)
│
└─ Connections (automatic between compatible input/output)
```
**Key rule**: All session configuration happens on a **dedicated serial queue**, never main thread.
## Core Patterns
### Pattern 1: Basic Session Setup
**Use case**: Set up camera preview with photo capture capability.
```swift
import AVFoundation
class CameraManager: NSObject {
let session = AVCaptureSession()
let photoOutput = AVCapturePhotoOutput()
// CRITICAL: Dedicated serial queue for session work
private let sessionQueue = DispatchQueue(label: "camera.session")
func setupSession() {
sessionQueue.async { [self] in
session.beginConfiguration()
defer { session.commitConfiguration() }
// 1. Set session preset
session.sessionPreset = .photo
// 2. Add camera input
guard let camera = AVCaptureDevice.default(.builtInWideAngleCamera,
for: .video,
position: .back),
let input = try? AVCaptureDeviceInput(device: camera),
session.canAddInput(input) else {
return
}
session.addInput(input)
// 3. Add photo output
guard session.canAddOutput(photoOutput) else { return }
session.addOutput(photoOutput)
// 4. Configure photo output
photoOutput.isHighResolutionCaptureEnabled = true
photoOutput.maxPhotoQualityPrioritization = .quality
}
}
func startSession() {
sessionQueue.async { [self] in
if !session.isRunning {
session.startRunning() // Blocking call - never on main thread!
}
}
}
func stopSession() {
sessionQueue.async { [self] in
if session.isRunning {
session.stopRunning()
}
}
}
}
```
**Cost**: 30 min implementation
### Pattern 2: SwiftUI Camera Preview
**Use case**: Display camera preview in SwiftUI view.
```swift
import SwiftUI
import AVFoundation
struct CameraPreview: UIViewRepresentable {
let session: AVCaptureSession
func makeUIView(context: Context) -> PreviewView {
let view = PreviewView()
view.previewLayer.session = session
view.previewLayer.videoGravity = .resizeAspectFill
return view
}
func updateUIView(_ uiView: PreviewView, context: Context) {}
class PreviewView: UIView {
override class var layerClass: AnyClass { AVCaptureVideoPreviewLayer.self }
var previewLayer: AVCaptureVideoPreviewLayer { layer as! AVCaptureVideoPreviewLayer }
}
}
// Usage in SwiftUI
struct CameraView: View {
@StateObject private var camera = CameraManager()
var body: some View {
CameraPreview(session: camera.session)
.ignoresSafeArea()
.onAppear { camera.startSession() }
.onDisappear { camera.stopSession() }
}
}
```
**Cost**: 20 min implementation
### Pattern 3: Rotation Handling with RotationCoordinator (iOS 17+)
**Use case**: Keep preview and captured photos correctly oriented regardless of device rotation.
**Why RotationCoordinator**: Deprecated `videoOrientation` requires manual observation of device orientation. RotationCoordinator automatically tracks gravity and provides angles.
```swift
import AVFoundation
class CameraManager {
private var rotationCoordinator: AVCaptureDevice.RotationCoordinator?
private var rotationObservation: NSKeyValueObservation?
func setupRotationCoordinator(device: AVCaptureDevice, previewLayer: AVCaptureVideoPreviewLayer) {
// Create coordinator with device and preview layer
rotationCoordinator = AVCaptureDevice.RotationCoordinator(
device: device,
previewLayer: previewLayer
)
// Observe preview rotation changes
rotationObservation = rotationCoordinator?.observe(
\.videoRotationAngleForHorizonLevelPreview,
options: [.new]
) { [weak previewLayer] coordinator, _ in
// Update preview layer rotation on main thread
DispatchQueue.main.async {
previewLayer?.connection?.videoRotationAngle = coordinator.videoRotationAngleForHorizonLevelPreview
}
}
// Set initial rotation
previewLayer.connection?.videoRotationAngle = rotationCoordinator!.videoRotationAngleForHorizonLevelPreview
}
func captureRotationAngle() -> CGFloat {
// Use this angle when capturing photos
rotationCoordinator?.videoRotationAngleForHorizonLevelCapture ?? 0
}
}
```
**When capturing**:
```swift
func capturePhoto() {
let settings = AVCapturePhotoSettings()
// Apply rotation angle from coordinator
if let connection = photoOutput.connection(with: .video) {
connection.videoRotationAngle = captureRotationAngle()
}
photoOutput.capturePhoto(with: settings, delegate: self)
}
```
**Cost**: 45 min implementation, prevents 2+ hours debugging rotation issues
### Pattern 4: Responsive Capture Pipeline (iOS 17+)
**Use case**: Make photo capture feel instant with zero-shutter-lag, overlapping captures, and responsive button states.
**iOS 17+ introduces four complementary APIs** that work together for maximum responsiveness:
#### 4a. Zero Shutter Lag
Uses a ring buffer of recent frames to "time travel" back to the exact moment you tapped the shutter. Enabled automatically for iOS 17+ apps.
```swift
// Check if supported for current format
if photoOutput.isZeroShutterLagSupported {
// Enabled by default for apps linking iOS 17+
// Opt out if causing issues:
// photoOutput.isZeroShutterLagEnabled = false
}
```
**Why it matters**: Without ZSL, there's a delay between tap and frame capture. For action shots, the moment is already over.
**Requirements**: iPhone XS and newer. Does NOT apply to flash captures, manual exposure, bracketed captures, or constituent photo delivery.
#### 4b. Responsive Capture (Overlapping Captures)
Allows a new capture to start while the previous one is still processing:
```swift
// Check support first
if photoOutput.isZeroShutterLagSupported {
photoOutput.isZeroShutterLagEnabled = true // Required for responsive capture
if photoOutput.isResponsiveCaptureSupported {
photoOutput.isResponsiveCaptureEnabled = true
}
}
```
**Tradeoff**: Increases peak memory usage. If your app is memory-constrained, consider leaving disabled.
**Requirements**: A12 Bionic (iPhone XS) and newer.
#### 4c. Fast Capture Prioritization
Automatically adapts quality when taking multiple photos rapidly (like burst mode):
```swift
if photoOutput.isFastCapturePrioritizationSupported {
photoOutput.isFastCapturePrioritizationEnabled = true
// When enabled, rapid captures use "balanced" quality instead of "quality"
// to maintain consistent shot-to-shot time
}
```
**When to enable**: User-facing toggle ("Prioritize Faster Shooting" in Camera.app). Off by default because it reduces quality.
#### 4d. Readiness Coordinator (Button State Management)
**Critical for UX**: Provides synchronous updates for shutter button state without async lag.
```swift
class CameraManager {
private var readinessCoordinator: AVCapturePhotoOutputReadinessCoordinator!
func setupReadinessCoordinator() {
readinessCoordinator = AVCapturePhotoOutputReadinessCoordinator(photoOutput: photoOutput)
readinessCoordinator.delegate = self
}
func capturePhoto() {
var settings = AVCapturePhotoSettings()
settings.photoQualityPrioritization = .balanced
// Tell coordinator to track this capture BEFORE calling capturePhoto
readinessCoordinator.startTrackingCaptureRequest(using: settings)
photoOutput.capturePhoto(with: settings, delegate: self)
}
}
extension CameraManager: AVCapturePhotoOutputReadinessCoordinatorDelegate {
func readinessCoordinator(_ coordinator: AVCapturePhotoOutputReadinessCoordinator,
captureReadinessDidChange captureReadiness: AVCapturePhotoOutput.CaptureReadiness) {
DispatchQueue.main.async {
switch captureReadiness {
case .ready:
self.shutterButton.isEnabled = true
self.shutterButton.alpha = 1.0
case .notReadyMomentarily:
// Brief delay - disable to prevent double-tap
self.shutterButton.isEnabled = false
case .notReadyWaitingForCapture:
// Flash is firing - dim button
self.shutterButton.alpha = 0.5
case .notReadyWaitingForProcessing:
// Processing previous photo - show spinner
self.showProcessingIndicator()
case .sessionNotRunning:
self.shutterButton.isEnabled = false
@unknown default:
break
}
}
}
}
```
**Why use Readiness Coordinator**: Without it, you'd need to track capture state manually and users might spam the shutter button during processing.
#### Quality Prioritization (Baseline)
Still useful even without the new APIs:
```swift
func capturePhoto() {
var settings = AVCapturePhotoSettings()
// Speed vs Quality tradeoff
// .speed - Fastest capture, lower quality
// .balanced - Good default
// .quality - Best quality, may have delay
settings.photoQualityPrioritization = .speed
// For specific use cases:
// - Social sharing: .speed (users expect instant)
// - Document scanning: .quality (accuracy matters)
// - General photography: .balanced
photoOutput.capturePhoto(with: settings, delegate: self)
}
```
**Deferred Processing (iOS 17+)**:
For maximum responsiveness, capture returns immediately with proxy image, full Deep Fusion processing happens in background:
```swift
// Check support and enable deferred processing
if photoOutput.isAutoDeferredPhotoDeliverySupported {
photoOutput.isAutoDeferredPhotoDeliveryEnabled = true
}
```
**Delegate callbacks with deferred processing**:
```swift
// Called for BOTH regular photos AND deferred proxies
func photoOutput(_ output: AVCapturePhotoOutput,
didFinishProcessingPhoto photo: AVCapturePhoto,
error: Error?) {
guard error == nil else { return }
// Non-deferred photo - save directly
if !photo.isRawPhoto, let data = photo.fileDataRepresentation() {
savePhotoToLibrary(data)
}
}
// Called ONLY for deferred proxies - save to PhotoKit for later processing
func photoOutput(_ output: AVCapturePhotoOutput,
didFinishCapturingDeferredPhotoProxy deferredPhotoProxy: AVCaptureDeferredPhotoProxy,
error: Error?) {
guard error == nil else { return }
// CRITICAL: Save proxy to library ASAP before app is backgrounded
// App may be force-quit if memory pressure is high during backgrounding
guard let proxyData = deferredPhotoProxy.fileDataRepresentation() else { return }
Task {
try await PHPhotoLibrary.shared().performChanges {
let request = PHAssetCreationRequest.forAsset()
// Use .photoProxy resource type - triggers deferred processing in Photos
request.addResource(with: .photoProxy, data: proxyData, options: nil)
}
}
}
```
**When final processing happens**:
- On-demand when image is requested from PhotoKit
- Or automatically when device is idle (plugged in, not in use)
**Fetching images with deferred processing awareness**:
```swift
// Request with secondary degraded image for smoother UX
let options = PHImageRequestOptions()
options.allowSecondaryDegradedImage = true // New in iOS 17
PHImageManager.default().requestImage(
for: asset,
targetSize: targetSize,
contentMode: .aspectFill,
options: options
) { image, info in
let isDegraded = info?[PHImageResultIsDegradedKey] as? Bool ?? false
if isDegraded {
// First: Low quality (immediate)
// Second: Medium quality (new - while processing)
// Third callback will be final quality
self.showTemporaryImage(image)
} else {
// Final quality - processing complete
self.showFinalImage(image)
}
}
```
**Requirements**: iPhone 11 Pro and newer. Not used for flash captures or formats that don't benefit from extended processing.
**Important considerations**:
- Can't apply pixel buffer customizations (filters, metadata changes) to deferred photos
- Use PhotoKit adjustments after processing for edits
- Get proxy into library ASAP - limited time when backgrounded
**Cost**: 1 hour implementation, prevents "camera feels slow" complaints
### Pattern 5: Session Interruption Handling
**Use case**: Handle phone calls, multitasking, system camera usage.
```swift
class CameraManager {
private var interruptionObservers: [NSObjectProtocol] = []
func setupInterruptionHandling() {
// Session was interrupted
let interruptedObserver = NotificationCenter.default.addObserver(
forName: .AVCaptureSessionWasInterrupted,
object: session,
queue: .main
) { [weak self] notification in
guard let reason = notification.userInfo?[AVCaptureSessionInterruptionReasonKey] as? Int,
let interruptionReason = AVCaptureSession.InterruptionReason(rawValue: reason) else {
return
}
switch interruptionReason {
case .videoDeviceNotAvailableInBackground:
// App went to background - normal, will resume
self?.showPausedOverlay()
case .audioDeviceInUseByAnotherClient:
// Another app using audio
self?.showInterruptedBanner("Audio in use by another app")
case .videoDeviceInUseByAnotherClient:
// Another app using camera
self?.showInterruptedBanner("Camera in use by another app")
case .videoDeviceNotAvailableWithMultipleForegroundApps:
// Split View/Slide Over - camera not available
self?.showInterruptedBanner("Camera unavailable in Split View")
case .videoDeviceNotAvailableDueToSystemPressure:
// Thermal state - reduce quality or stop
self?.handleThermalPressure()
@unknown default:
self?.showInterruptedBanner("Camera interrupted")
}
}
interruptionObservers.append(interruptedObserver)
// Session interruption ended
let endedObserver = NotificationCenter.default.addObserver(
forName: .AVCaptureSessionInterruptionEnded,
object: session,
queue: .main
) { [weak self] _ in
self?.hideInterruptedBanner()
self?.hidePausedOverlay()
// Session automatically resumes - no need to call startRunning()
}
interruptionObservers.append(endedObserver)
}
deinit {
interruptionObservers.forEach { NotificationCenter.default.removeObserver($0) }
}
}
```
**Cost**: 30 min implementation, prevents "camera freezes" bug reports
### Pattern 6: Camera Switching (Front/Back)
**Use case**: Toggle between front and back cameras.
```swift
func switchCamera() {
sessionQueue.async { [self] in
guard let currentInput = session.inputs.first as? AVCaptureDeviceInput else {
return
}
let currentPosition = currentInput.device.position
let newPosition: AVCaptureDevice.Position = currentPosition == .back ? .front : .back
guard let newDevice = AVCaptureDevice.default(
.builtInWideAngleCamera,
for: .video,
position: newPosition
) else {
return
}
session.beginConfiguration()
defer { session.commitConfiguration() }
// Remove old input
session.removeInput(currentInput)
// Add new input
do {
let newInput = try AVCaptureDeviceInput(device: newDevice)
if session.canAddInput(newInput) {
session.addInput(newInput)
// Update rotation coordinator for new device
if let previewLayer = previewLayer {
setupRotationCoordinator(device: newDevice, previewLayer: previewLayer)
}
} else {
// Fallback: restore old input
session.addInput(currentInput)
}
} catch {
session.addInput(currentInput)
}
}
}
```
**Front camera mirroring**: Front camera preview is mirrored by default (matches user expectation). Captured photos are NOT mirrored (correct for sharing). This is intentional.
**Cost**: 20 min implementation
### Pattern 7: Video Recording
**Use case**: Record video with audio to file.
```swift
class CameraManager: NSObject {
let movieOutput = AVCaptureMovieFileOutput()
private var currentRecordingURL: URL?
func setupVideoRecording() {
sessionQueue.async { [self] in
session.beginConfiguration()
defer { session.commitConfiguration() }
// Set video preset
session.sessionPreset = .high // Or .hd1920x1080, .hd4K3840x2160
// Add microphone input
if let microphone = AVCaptureDevice.default(for: .audio),
let audioInput = try? AVCaptureDeviceInput(device: microphone),
session.canAddInput(audioInput) {
session.addInput(audioInput)
}
// Add movie output
if session.canAddOutput(movieOutput) {
session.addOutput(movieOutput)
}
}
}
func startRecording() {
guard !movieOutput.isRecording else { return }
let outputURL = FileManager.default.temporaryDirectory
.appendingPathComponent(UUID().uuidString)
.appendingPathExtension("mov")
currentRecordingURL = outputURL
// Apply rotation
if let connection = movieOutput.connection(with: .video) {
connection.videoRotationAngle = captureRotationAngle()
}
movieOutput.startRecording(to: outputURL, recordingDelegate: self)
}
func stopRecording() {
guard movieOutput.isRecording else { return }
movieOutput.stopRecording()
}
}
extension CameraManager: AVCaptureFileOutputRecordingDelegate {
func fileOutput(_ output: AVCaptureFileOutput,
didFinishRecordingTo outputFileURL: URL,
from connections: [AVCaptureConnection],
error: Error?) {
if let error = error {
print("Recording error: \(error)")
return
}
// Video saved to outputFileURL
saveVideoToPhotoLibrary(outputFileURL)
}
}
```
**Cost**: 45 min implementation
## Anti-Patterns
### Anti-Pattern 1: Session Work on Main Thread
**Wrong**:
```swift
func startCamera() {
session.startRunning() // Blocks UI for 1-3 seconds!
}
```
**Right**:
```swift
func startCamera() {
sessionQueue.async { [self] in
session.startRunning()
}
}
```
**Why it matters**: `startRunning()` is blocking. On main thread, UI freezes.
### Anti-Pattern 2: Using Deprecated videoOrientation
**Wrong** (pre-iOS 17):
```swift
// Manually tracking orientation
NotificationCenter.default.addObserver(
forName: UIDevice.orientationDidChangeNotification,
object: nil,
queue: .main
) { _ in
// Manual rotation logic...
}
```
**Right** (iOS 17+):
```swift
let coordinator = AVCaptureDevice.RotationCoordinator(device: camera, previewLayer: preview)
// Automatically tracks gravity, provides angles
```
**Why it matters**: RotationCoordinator handles edge cases (face-up, face-down) that manual tracking misses.
### Anti-Pattern 3: Ignoring Session Interruptions
**Wrong**:
```swift
// No interruption handling - camera freezes on phone call
```
**Right**:
```swift
NotificationCenter.default.addObserver(
forName: .AVCaptureSessionWasInterrupted,
object: session,
queue: .main
) { notification in
// Show UI feedback
}
```
**Why it matters**: Without handling, camera appears frozen when interrupted.
### Anti-Pattern 4: Modifying Session Without Configuration Block
**Wrong**:
```swift
session.removeInput(oldInput)
session.addInput(newInput) // May fail mid-stream
```
**Right**:
```swift
session.beginConfiguration()
session.removeInput(oldInput)
session.addInput(newInput)
session.commitConfiguration() // Atomic change
```
**Why it matters**: Without configuration block, session may enter invalid state between calls.
## Pressure Scenarios
### Scenario 1: "Just Make the Camera Work by Friday"
**Context**: Product wants camera feature shipped. You're considering skipping interruption handling.
**Pressure**: "It works when I test it, let's ship."
**Reality**: First user who gets a phone call while using camera will see frozen UI. App Store review may catch this.
**Correct action**:
1. Implement interruption handling (30 min)
2. Test by calling your test device during camera use
3. Verify UI shows appropriate feedback
**Push-back template**: "Camera captures work, but the app freezes if a phone call comes in. I need 30 minutes to handle interruptions properly and avoid 1-star reviews."
### Scenario 2: "The Camera is Too Slow"
**Context**: QA reports photo capture feels sluggish. PM wants it "instant like the system camera."
**Pressure**: "Just make it faster somehow."
**Reality**: Default settings prioritize quality over speed. System camera uses deferred processing.
**Correct action**:
1. Set `photoQualityPrioritization = .speed` for social/sharing use cases
2. Consider deferred processing for maximum responsiveness
3. Show capture animation immediately (before processing completes)
**Push-back template**: "We're currently optimizing for image quality. I can make capture feel instant by prioritizing speed and showing the preview immediately while processing continues in background. This is what the system Camera app does."
### Scenario 3: "Why is the Front Camera Photo Mirrored?"
**Context**: Designer reports front camera photos look "wrong" - they're not mirrored like the preview.
**Pressure**: "The preview shows it one way, the photo should match."
**Reality**: Preview is mirrored (user expectation - like a mirror). Photo is NOT mirrored (correct for sharing - text reads correctly). This is intentional behavior matching system camera.
**Correct action**:
1. Explain this is Apple's standard behavior
2. If business requires mirrored photos (selfie apps), manually mirror in post-processing
3. Never mirror the preview differently than expected
**Push-back template**: "This is intentional Apple behavior. The preview is mirrored like a mirror so users can frame themselves, but the captured photo is unmirrored so text reads correctly when shared. We can add optional mirroring in post-processing if our use case requires it."
## Checklist
Before shipping camera features:
**Session Setup**:
- ☑ All session work on dedicated serial queue
- ☑ `startRunning()` never called on main thread
- ☑ Session preset matches use case (`.photo` for photos, `.high` for video)
- ☑ Configuration changes wrapped in `beginConfiguration()`/`commitConfiguration()`
**Permissions**:
- ☑ Camera permission requested before session setup
- ☑ `NSCameraUsageDescription` in Info.plist
- ☑ `NSMicrophoneUsageDescription` if recording audio
- ☑ Graceful handling of denied permission
**Rotation**:
- ☑ RotationCoordinator used (not deprecated videoOrientation)
- ☑ Preview layer rotation updated via observation
- ☑ Capture rotation angle applied when taking photos
- ☑ Tested in all orientations (portrait, landscape, face-up)
**Responsiveness**:
- ☑ photoQualityPrioritization set appropriately for use case
- ☑ Capture button shows immediate feedback
- ☑ Deferred processing considered for maximum speed
**Interruptions**:
- ☑ Session interruption observer registered
- ☑ UI feedback shown when interrupted
- ☑ Tested with incoming phone call
- ☑ Tested in Split View (iPad)
**Camera Switching**:
- ☑ Front/back switch updates rotation coordinator
- ☑ Switch happens on session queue
- ☑ Fallback if new camera unavailable
**Video Recording** (if applicable):
- ☑ Microphone input added
- ☑ Recording delegate handles completion
- ☑ File cleanup for temporary recordings
## Resources
**WWDC**: 2021-10247, 2023-10105
**Docs**: /avfoundation/avcapturesession, /avfoundation/avcapturedevice/rotationcoordinator, /avfoundation/avcapturephotosettings, /avfoundation/avcapturephotooutputreadinesscoordinator
**Skills**: axiom-camera-capture-ref, axiom-camera-capture-diag, axiom-photo-library

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interface:
display_name: "Camera Capture"
short_description: "AVCaptureSession, camera preview, photo capture, video recording, RotationCoordinator, session interruptions, deferre..."