Camera Capture API Reference

API reference for AVFoundation camera capture: AVCaptureSession, AVCaptureDevice, AVCapturePhotoOutput, RotationCoordinator, the responsive capture APIs, and video recording. Use it to look up exact class names, settings, and states while building a camera feature.

When to Use This Reference

Use this reference when:

• Looking up AVCaptureSession presets and configuration APIs
• Checking AVCapturePhotoSettings options (quality, flash, format, resolution)
• Implementing RotationCoordinator for automatic rotation handling
• Understanding ReadinessCoordinator delegate states for shutter button UX
• Configuring AVCaptureMovieFileOutput for video recording
• Setting up AVCaptureVideoPreviewLayer in SwiftUI or UIKit
• Looking up device types, discovery sessions, or device configuration APIs
• Adopting deferred start for fast camera launch (iOS 26 and later)
• Supporting the Center Stage front camera: dynamic aspect ratio, smart framing, sensor orientation compensation (iPhone 17, iPhone Air, and iPhone 17 Pro; iOS 26 and later)
• Capturing 24 or 48 megapixel photos with prepared photo settings
• Recording ProRes with Pro Video Storage (iOS 27)
• Setting lens aperture, shutter, or ISO priority modes, or tuning exposure signals (iOS 27)
• Enabling continuous autofocus tracking, low-light video noise reduction, or cinematic video metadata capture (iOS 27)
• Choosing a camera by direction on iPhone Duo (iOS 27.1+)

Example Prompts

Questions you can ask your assistant that will draw from this reference:

• "What are all the AVCaptureSession presets?"
• "How does AVCapturePhotoOutputReadinessCoordinator work?"
• "What AVCaptureDevice types are available?"
• "How do I configure AVCapturePhotoSettings for HEIF format?"
• "What are the responsive capture APIs in iOS 17+?"
• "How do I set up AVCaptureVideoPreviewLayer in SwiftUI?"
• "What are the session interruption reasons?"
• "How does deferred start work?"
• "How do I set the front camera's aspect ratio without rotating the phone?"
• "What resolutions does each photo quality prioritization support?"
• "How do I choose a camera by direction instead of position on iPhone Duo?"
• "How do I set the lens aperture, or use aperture priority, on iOS 27?"
• "How do I keep a moving subject in focus while recording?"
• "How do I record video I can edit cinematically afterwards?"

What's Covered

Session

• AVCaptureSession presets, configuration, lifecycle, notifications, and interruption reasons
• Deferred start for fast launch (iOS 26 and later)
• hardwareCost and systemPressureCost

Devices

• AVCaptureDevice types, discovery sessions, and configuration (focus, exposure, zoom, torch)
• Switching cameras and camera authorization
• Lens aperture, exposure priority modes, and exposure signals (iOS 27)
• Continuous autofocus tracking and focus-tracked metadata objects (iOS 27)
• Center Stage front camera: dynamic aspect ratio, smart framing monitor, sensor orientation compensation, Center Stage control mode and stabilization (iOS 26 and later)
• iPhone Duo front cameras: the virtual front camera, the individual inner and outer ultra-wide cameras, choosing a camera by direction, mirroring (iOS 27.1+; build with Xcode 27.1, because Xcode 27.2 beta 2 lacks these types)
• AVCaptureDevice.RotationCoordinator setup, properties, and KVO observation (iOS 17+)

Photo Capture

• AVCapturePhotoOutput configuration, responsive capture APIs, and deferred processing
• High-resolution capture (24 or 48 MP) with prepared photo settings
• AVCapturePhotoOutputReadinessCoordinator delegate and capture readiness states
• AVCapturePhotoSettings formats (JPEG, HEIF, RAW), quality prioritization, flash, Apple ProRAW and HDR, resolution, previews and thumbnails
• AVCapturePhotoCaptureDelegate callbacks, including deferred proxy handling

Video Recording

• AVCaptureMovieFileOutput recording, delegate, and state properties
• Low-light video noise reduction on the connection (iOS 27)
• Cinematic video metadata capture, with the handoff to the Cinematic framework for editing (iOS 27)
• Pro Video Storage for deterministic high-data-rate recording (iOS 27)

Other 27-Cycle Additions

• AVCaptureBroadcastVideoOutput and its ancillaryDataEncoder
• AVExternalStorageDevice.reasonsNotRecommendedForCaptureUse
• External-sync AVError cases
• setPrimaryConstituentDeviceSwitchingBehaviorLockedWith(_:)

Preview and Patterns

• AVCaptureVideoPreviewLayer video gravity options and SwiftUI integration
• A complete CameraManager pattern with @MainActor, async setup, and rotation

Documentation Scope

This page documents the camera-capture-ref skill (in the axiom-media suite), the API reference your assistant uses for AVFoundation camera classes. The skill holds the full API detail and code examples.

Key APIs

Session Presets

Preset	Resolution	Use Case
.photo	Optimal for photos	Photo capture
.high	Highest device quality	Video recording
.medium	VGA quality	Preview, lower storage
.low	CIF quality	Minimal storage
.hd1280x720	720p	HD video
.hd1920x1080	1080p	Full HD video
.hd4K3840x2160	4K	Ultra HD video
.inputPriority	Use device format	Custom configuration

Quality Prioritization

Value	Speed	Quality	Use Case
.speed	Fastest	Lower	Social sharing, rapid capture
.balanced	Medium	Good	General photography
.quality	Slowest	Best	Professional, documents

Capture Readiness States

State	Meaning
.ready	Can capture immediately
.notReadyMomentarily	Brief delay, prevent double-tap
.notReadyWaitingForCapture	Flash firing, sensor reading
.notReadyWaitingForProcessing	Processing previous photo
.sessionNotRunning	Session stopped

Related

• camera-capture – Guided implementation patterns and session setup that use these APIs
• camera-capture-diag – Troubleshooting a black preview, a frozen session, or rotation bugs
• camera-auditor – Agent that scans your capture code for deprecated APIs, missing interruption handling, and threading mistakes
• avfoundation-video-ref – Writing and exporting the video you capture, and typed buffer attachments
• photo-library-ref – Saving captured photos to the library, and the photo picker

Resources

WWDC: 2023-10105, 2026-303, 2026-304, 2026-341

Tech Talks: 111465

Docs: /avfoundation/avcapturesession, /avfoundation/avcapturedevice, /avfoundation/avcapturephotosettings, /avfoundation/avcapturedevice/rotationcoordinator, /avfoundation/avprovideostorage, /avfoundation/avcapturesmartframingmonitor