| 1 | import AVFoundation |
| 2 | import Foundation |
| 3 | import LiveKitWebRTC |
| 4 | import os |
| 5 | |
| 6 | #if os(macOS) |
| 7 | import AppKit |
| 8 | #else |
| 9 | import UIKit |
| 10 | #endif |
| 11 | |
| 12 | /// One camera the person can choose, named the way a menu wants it. |
| 13 | /// |
| 14 | /// The id is `AVCaptureDevice.uniqueID`, which survives unplugging and |
| 15 | /// replugging the same camera, so a remembered choice means the same |
| 16 | /// device next time rather than whatever now sits at that index. |
| 17 | public struct CameraDevice: Identifiable, Hashable, Sendable { |
| 18 | public let id: String |
| 19 | public let name: String |
| 20 | /// The Mac's own camera (the iPhone's front one): where a call goes |
| 21 | /// when the remembered camera is not connected. |
| 22 | public let builtIn: Bool |
| 23 | /// `AVCaptureDevice.modelID`: the same for the same kind of camera |
| 24 | /// wherever it is plugged in. A USB camera's `uniqueID` is built from |
| 25 | /// the port it is on, so an ATEM Mini moved to another port (or through |
| 26 | /// a different hub) comes back under a new id; the model, and failing |
| 27 | /// that the name, is how a remembered choice still finds it. |
| 28 | public let model: String |
| 29 | /// `AVCaptureDevice.isSuspended`: listed and connected, but the system |
| 30 | /// will not let it capture. On a Mac this is the built-in camera with |
| 31 | /// the lid closed, where it opens and never sends a frame. |
| 32 | public let suspended: Bool |
| 33 | public init(id: String, name: String, builtIn: Bool = false, model: String = "", suspended: Bool = false) { |
| 34 | self.id = id |
| 35 | self.name = name |
| 36 | self.builtIn = builtIn |
| 37 | self.model = model |
| 38 | self.suspended = suspended |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | // Capture is injected separately from signaling and rendering. App targets |
| 43 | // provide the platform camera; the interop executable provides synthetic frames. |
| 44 | @MainActor public protocol VideoCapture: AnyObject { |
| 45 | func start(source: RTCVideoSource) async throws |
| 46 | func stop() |
| 47 | |
| 48 | /// The cameras this capture can offer, and which one it is on. A capture |
| 49 | /// with nothing to choose between answers an empty list, and the picker |
| 50 | /// does not appear — which is what the interop executable's synthetic |
| 51 | /// frames want, and why these carry defaults rather than being required. |
| 52 | var cameras: [CameraDevice] { get } |
| 53 | var currentCamera: String? { get } |
| 54 | func use(camera id: String) async throws |
| 55 | |
| 56 | /// Whether the call should always show a Camera row, even with no |
| 57 | /// camera to list: true for real cameras, where "No camera found" is |
| 58 | /// something a person needs to be told. |
| 59 | var offersCameras: Bool { get } |
| 60 | /// What the camera is doing, for the self tile and the panel. Nil for a |
| 61 | /// capture that does not say. |
| 62 | var cameraStatus: CameraStatus? { get } |
| 63 | /// A fallback worth saying ("ATEM Mini disconnected; using FaceTime HD |
| 64 | /// Camera"), and usually nothing. |
| 65 | var cameraNote: String { get } |
| 66 | /// The camera in use when it is working and is not the remembered one: |
| 67 | /// what the panel offers to remember ("Use Blackmagic Design from now |
| 68 | /// on"). Nil otherwise. |
| 69 | var cameraToKeep: CameraDevice? { get } |
| 70 | /// Called on the main actor whenever any of the above changes on its |
| 71 | /// own — a camera connecting, a fallback, the first frame. |
| 72 | func observe(_ changed: @escaping @MainActor () -> Void) |
| 73 | /// The panel's "Try again". |
| 74 | func retryCamera() async |
| 75 | } |
| 76 | |
| 77 | extension VideoCapture { |
| 78 | public var cameras: [CameraDevice] { [] } |
| 79 | public var currentCamera: String? { nil } |
| 80 | public func use(camera id: String) async throws {} |
| 81 | public var offersCameras: Bool { false } |
| 82 | public var cameraStatus: CameraStatus? { nil } |
| 83 | public var cameraNote: String { "" } |
| 84 | public var cameraToKeep: CameraDevice? { nil } |
| 85 | public func observe(_ changed: @escaping @MainActor () -> Void) {} |
| 86 | public func retryCamera() async {} |
| 87 | } |
| 88 | |
| 89 | /// A screen, as §5.4 sends one: frames into a source of its own, which |
| 90 | /// the call carries on a `sendonly` transceiver beside the camera's. |
| 91 | /// |
| 92 | /// `start` returns once the person has chosen what to share and frames |
| 93 | /// are on their way; a refusal at the system's own picker is a throw, and |
| 94 | /// nothing has been announced. `ended` is for the capture ending on its |
| 95 | /// own — the system's stop control, a shared window closing, a broadcast |
| 96 | /// stopped from Control Center — and is called at most once, on the main |
| 97 | /// actor. `stop` is the call ending it, and calls nothing back. |
| 98 | @MainActor public protocol ScreenCapture: AnyObject { |
| 99 | func start(source: RTCVideoSource, ended: @escaping @MainActor () -> Void) async throws |
| 100 | func stop() |
| 101 | /// What the capture has produced so far, for the screen watchdog. |
| 102 | var counts: ScreenCaptureCounts { get } |
| 103 | /// Starts the same capture again — the same content into the same |
| 104 | /// source — after the watchdog has seen it stall. False when this kind |
| 105 | /// of capture cannot, or the attempt failed. |
| 106 | func restart() async -> Bool |
| 107 | /// The size the capture delivers frames at, when it knows before the |
| 108 | /// first frame: the send policy's H.264 level cap (ScreenSendPolicy) |
| 109 | /// then holds from the first frame rather than from the first |
| 110 | /// statistics a second later, a second in which a browser's level-3.1 |
| 111 | /// encoder refuses every frame of a Motion share (spec §15.22). |
| 112 | var frameSize: (width: Int, height: Int)? { get } |
| 113 | } |
| 114 | |
| 115 | extension ScreenCapture { |
| 116 | public var counts: ScreenCaptureCounts { ScreenCaptureCounts() } |
| 117 | public func restart() async -> Bool { false } |
| 118 | public var frameSize: (width: Int, height: Int)? { nil } |
| 119 | } |
| 120 | |
| 121 | /// A screen capture's running totals (see ScreenWatchdog). |
| 122 | public struct ScreenCaptureCounts: Equatable, Sendable { |
| 123 | /// Everything the capture has reported, still-screen reports included: |
| 124 | /// ScreenCaptureKit reports "idle" at the frame rate while nothing on |
| 125 | /// screen changes (measured 2026-09-28: 177 idle reports in six seconds |
| 126 | /// of a still window), so a capture that reports nothing at all has |
| 127 | /// stopped, not gone quiet. Nil for a capture that cannot tell the two |
| 128 | /// apart — a ReplayKit broadcast sends nothing for a still screen — |
| 129 | /// which turns the watchdog's capture check off for it. |
| 130 | public var heartbeats: UInt64? |
| 131 | /// Frames handed to the call's source, repeats of a still screen included. |
| 132 | public var delivered: UInt64 = 0 |
| 133 | |
| 134 | public init(heartbeats: UInt64? = nil, delivered: UInt64 = 0) { |
| 135 | self.heartbeats = heartbeats |
| 136 | self.delivered = delivered |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | // --------------------------------------------------------------------- |
| 141 | // The managed camera: device choice, recovery and the watchdog |
| 142 | // --------------------------------------------------------------------- |
| 143 | |
| 144 | /// Where frames actually come from, under the recovery rules: AVFoundation |
| 145 | /// in the apps, synthetic frames in the interop gate. Everything about |
| 146 | /// *which* camera and *when to try again* lives in `ManagedCamera` and |
| 147 | /// `CameraDirector`; a backend only lists, opens and closes. |
| 148 | @MainActor public protocol CameraBackend: AnyObject { |
| 149 | /// Asks for camera (and microphone) permission. Throws when refused. |
| 150 | func requestAccess() async throws |
| 151 | /// The cameras connected now. |
| 152 | var devices: [CameraDevice] { get } |
| 153 | /// How many formats `open` can be asked for on this device, ranked. |
| 154 | func formatCount(_ id: String) -> Int |
| 155 | /// Opens the device in its ranked format, delivering frames to |
| 156 | /// `delegate`. Throws when it will not open. |
| 157 | func open(_ id: String, format: Int, delegate: RTCVideoCapturerDelegate) async throws |
| 158 | func close() async |
| 159 | /// Set by the managed camera: the device list changed. |
| 160 | var devicesChanged: (@MainActor () -> Void)? { get set } |
| 161 | /// Set by the managed camera: the session reported an error or an |
| 162 | /// interruption, or the machine woke. Capture should be restarted. |
| 163 | var trouble: (@MainActor () -> Void)? { get set } |
| 164 | } |
| 165 | |
| 166 | /// Counts frames on their way to the video source, which is all the |
| 167 | /// watchdog needs to know whether a camera is working. The capturer holds |
| 168 | /// its delegate weakly, so the managed camera holds this. |
| 169 | final class FrameCounter: NSObject, RTCVideoCapturerDelegate, @unchecked Sendable { |
| 170 | private let source: RTCVideoSource |
| 171 | private let lock = OSAllocatedUnfairLock(initialState: UInt64(0)) |
| 172 | init(source: RTCVideoSource) { self.source = source } |
| 173 | var count: UInt64 { lock.withLock { $0 } } |
| 174 | func capturer(_ capturer: RTCVideoCapturer, didCapture frame: RTCVideoFrame) { |
| 175 | lock.withLock { $0 += 1 } |
| 176 | source.capturer(capturer, didCapture: frame) |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | /// A camera under the recovery rules (see `CameraDirector`): remembered |
| 181 | /// between calls, followed as devices come and go, and watched for frames. |
| 182 | /// |
| 183 | /// Every open and close runs one at a time, and an open the director has |
| 184 | /// since moved on from is skipped, so the last decision is the one that |
| 185 | /// holds. |
| 186 | @MainActor public final class ManagedCamera: VideoCapture { |
| 187 | private let backend: CameraBackend |
| 188 | private let director: CameraDirector |
| 189 | private var counter: FrameCounter? |
| 190 | private var work: Task<Void, Never>? |
| 191 | private var ticker: Task<Void, Never>? |
| 192 | private var running = false |
| 193 | private var changed: (@MainActor () -> Void)? |
| 194 | private(set) public var currentCamera: String? |
| 195 | /// Opens performed, for the gate: a stall that recovered is one more. |
| 196 | public private(set) var opens = 0 |
| 197 | private let clock: () -> TimeInterval |
| 198 | var tickInterval: Duration = .milliseconds(500) |
| 199 | |
| 200 | public init( |
| 201 | backend: CameraBackend, defaults: UserDefaults = .standard, |
| 202 | clock: @escaping () -> TimeInterval = { ProcessInfo.processInfo.systemUptime } |
| 203 | ) { |
| 204 | self.backend = backend |
| 205 | self.clock = clock |
| 206 | director = CameraDirector(defaults: defaults, formats: { [weak backend] in backend?.formatCount($0) ?? 1 }) |
| 207 | backend.devicesChanged = { [weak self] in self?.devicesChanged() } |
| 208 | backend.trouble = { [weak self] in self?.trouble() } |
| 209 | } |
| 210 | |
| 211 | public var cameras: [CameraDevice] { backend.devices } |
| 212 | public var offersCameras: Bool { true } |
| 213 | public var cameraStatus: CameraStatus? { running ? director.status : nil } |
| 214 | public var cameraNote: String { running ? director.note : "" } |
| 215 | public var cameraToKeep: CameraDevice? { running ? director.cameraToKeep : nil } |
| 216 | public func observe(_ changed: @escaping @MainActor () -> Void) { self.changed = changed } |
| 217 | |
| 218 | public func start(source: RTCVideoSource) async throws { |
| 219 | try await backend.requestAccess() |
| 220 | counter = FrameCounter(source: source) |
| 221 | running = true |
| 222 | ticker = Task { @MainActor [weak self] in |
| 223 | var slow = 0 |
| 224 | while !Task.isCancelled { |
| 225 | guard let self else { return } |
| 226 | try? await Task.sleep(for: self.tickInterval) |
| 227 | guard !Task.isCancelled else { return } |
| 228 | self.tick() |
| 229 | // Belt and braces for the device notifications: while there is no |
| 230 | // working camera, look again every few seconds. |
| 231 | slow += 1 |
| 232 | if slow % 6 == 0, !(self.director.status.live) { self.devicesChanged() } |
| 233 | } |
| 234 | } |
| 235 | // Returns once the first open has been tried, so a call starts with |
| 236 | // its camera (or its reason for having none) already known. |
| 237 | await perform(director.start(devices: backend.devices)) |
| 238 | } |
| 239 | |
| 240 | public func stop() { |
| 241 | running = false |
| 242 | ticker?.cancel() |
| 243 | ticker = nil |
| 244 | director.stop() |
| 245 | currentCamera = nil |
| 246 | let backend = backend |
| 247 | let previous = work |
| 248 | work = Task { @MainActor in |
| 249 | await previous?.value |
| 250 | await backend.close() |
| 251 | } |
| 252 | counter = nil |
| 253 | } |
| 254 | |
| 255 | public func use(camera id: String) async throws { |
| 256 | guard running else { return } |
| 257 | guard let command = director.choose(id) else { |
| 258 | throw NSError( |
| 259 | domain: "Calls", code: 4, |
| 260 | userInfo: [NSLocalizedDescriptionKey: "That camera is no longer available."]) |
| 261 | } |
| 262 | await perform(command) |
| 263 | } |
| 264 | |
| 265 | public func retryCamera() async { |
| 266 | guard running else { return } |
| 267 | await perform(director.retry()) |
| 268 | } |
| 269 | |
| 270 | private func tick() { |
| 271 | guard running, let counter else { return } |
| 272 | #if os(iOS) |
| 273 | // iOS stops every camera while the app is in the background; that |
| 274 | // is not a stall to recover from. |
| 275 | if UIApplication.shared.applicationState != .active { |
| 276 | director.hold(frames: counter.count, at: clock()) |
| 277 | return |
| 278 | } |
| 279 | #endif |
| 280 | if let command = director.tick(frames: counter.count, at: clock()) { |
| 281 | Task { await self.perform(command) } |
| 282 | } |
| 283 | notify() |
| 284 | } |
| 285 | |
| 286 | private func devicesChanged() { |
| 287 | guard running else { |
| 288 | changed?() |
| 289 | return |
| 290 | } |
| 291 | if let command = director.devicesChanged(backend.devices) { |
| 292 | Task { await self.perform(command) } |
| 293 | } |
| 294 | notify() |
| 295 | } |
| 296 | |
| 297 | private func trouble() { |
| 298 | guard running else { return } |
| 299 | if let command = director.restart(at: clock()) { |
| 300 | Task { await self.perform(command) } |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | private var published: (CameraStatus, String, String?, CameraDevice?)? |
| 305 | private func notify() { |
| 306 | let now = (director.status, director.note, currentCamera, director.cameraToKeep) |
| 307 | if let published, published == now { return } |
| 308 | published = now |
| 309 | changed?() |
| 310 | } |
| 311 | |
| 312 | /// Runs a command after whatever is running, and returns when it has. |
| 313 | private func perform(_ command: CameraCommand?) async { |
| 314 | guard let command else { |
| 315 | notify() |
| 316 | return |
| 317 | } |
| 318 | let previous = work |
| 319 | let task = Task { @MainActor [weak self] in |
| 320 | await previous?.value |
| 321 | await self?.execute(command) |
| 322 | } |
| 323 | work = task |
| 324 | await task.value |
| 325 | } |
| 326 | |
| 327 | private func execute(_ command: CameraCommand) async { |
| 328 | guard running else { return } |
| 329 | switch command { |
| 330 | case .stop: |
| 331 | await backend.close() |
| 332 | currentCamera = nil |
| 333 | notify() |
| 334 | case .open(let id, let format): |
| 335 | // The director has moved on (a later pick, a fallback): skip. |
| 336 | guard director.active == id, director.format == format, let counter else { return } |
| 337 | await backend.close() |
| 338 | currentCamera = nil |
| 339 | notify() |
| 340 | guard running, director.active == id else { return } |
| 341 | do { |
| 342 | try await backend.open(id, format: format, delegate: counter) |
| 343 | opens += 1 |
| 344 | guard running, director.active == id else { return } |
| 345 | currentCamera = id |
| 346 | director.opened(id, at: clock(), frames: counter.count) |
| 347 | } catch { |
| 348 | guard running, director.active == id else { return } |
| 349 | if let next = director.openFailed(id) { |
| 350 | notify() |
| 351 | await execute(next) |
| 352 | return |
| 353 | } |
| 354 | } |
| 355 | notify() |
| 356 | } |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | // --------------------------------------------------------------------- |
| 361 | // AVFoundation |
| 362 | // --------------------------------------------------------------------- |
| 363 | |
| 364 | /// The cameras connected to this device, followed as they come and go: |
| 365 | /// AVFoundation's connect and disconnect notifications, and on Mac the |
| 366 | /// discovery session's device list by KVO. One for the process, so the |
| 367 | /// panel can list cameras whether or not a capture is running. |
| 368 | @MainActor public final class CameraWatch { |
| 369 | public static let shared = CameraWatch() |
| 370 | public private(set) var cameras: [CameraDevice] = [] |
| 371 | private var listeners: [UUID: @MainActor () -> Void] = [:] |
| 372 | private var tokens: [NSObjectProtocol] = [] |
| 373 | /// Each listed camera's `isSuspended`, watched: the lid closing or |
| 374 | /// opening changes it without any camera connecting or leaving. |
| 375 | private var suspension: [String: NSKeyValueObservation] = [:] |
| 376 | #if os(macOS) |
| 377 | private let session = AVCaptureDevice.DiscoverySession( |
| 378 | deviceTypes: [.builtInWideAngleCamera, .external, .continuityCamera], |
| 379 | mediaType: .video, position: .unspecified) |
| 380 | private var kvo: NSKeyValueObservation? |
| 381 | #endif |
| 382 | |
| 383 | private init() { |
| 384 | for name in [AVCaptureDevice.wasConnectedNotification, AVCaptureDevice.wasDisconnectedNotification] { |
| 385 | tokens.append( |
| 386 | NotificationCenter.default.addObserver(forName: name, object: nil, queue: .main) { _ in |
| 387 | MainActor.assumeIsolated { CameraWatch.shared.refresh() } |
| 388 | }) |
| 389 | } |
| 390 | #if os(macOS) |
| 391 | kvo = session.observe(\.devices, options: [.new]) { _, _ in |
| 392 | DispatchQueue.main.async { MainActor.assumeIsolated { CameraWatch.shared.refresh() } } |
| 393 | } |
| 394 | #endif |
| 395 | cameras = Self.list(devices) |
| 396 | watchSuspension() |
| 397 | } |
| 398 | |
| 399 | private func watchSuspension() { |
| 400 | let current = devices |
| 401 | let ids = Set(current.map(\.uniqueID)) |
| 402 | for id in suspension.keys where !ids.contains(id) { suspension.removeValue(forKey: id) } |
| 403 | for device in current where suspension[device.uniqueID] == nil { |
| 404 | suspension[device.uniqueID] = device.observe(\.isSuspended, options: [.new]) { _, _ in |
| 405 | DispatchQueue.main.async { MainActor.assumeIsolated { CameraWatch.shared.refresh() } } |
| 406 | } |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | var devices: [AVCaptureDevice] { |
| 411 | #if os(macOS) |
| 412 | session.devices |
| 413 | #else |
| 414 | RTCCameraVideoCapturer.captureDevices() |
| 415 | #endif |
| 416 | } |
| 417 | |
| 418 | func device(_ id: String) -> AVCaptureDevice? { devices.first { $0.uniqueID == id } } |
| 419 | |
| 420 | static func list(_ devices: [AVCaptureDevice]) -> [CameraDevice] { |
| 421 | devices.filter(\.isConnected).map { |
| 422 | #if os(macOS) |
| 423 | let builtIn = $0.deviceType == .builtInWideAngleCamera |
| 424 | #else |
| 425 | let builtIn = $0.position == .front |
| 426 | #endif |
| 427 | return CameraDevice( |
| 428 | id: $0.uniqueID, name: $0.localizedName, builtIn: builtIn, model: $0.modelID, |
| 429 | suspended: $0.isSuspended) |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | public func refresh() { |
| 434 | let now = Self.list(devices) |
| 435 | guard now != cameras else { return } |
| 436 | watchSuspension() |
| 437 | cameras = now |
| 438 | for listener in listeners.values { listener() } |
| 439 | } |
| 440 | |
| 441 | func listen(_ listener: @escaping @MainActor () -> Void) -> UUID { |
| 442 | let id = UUID() |
| 443 | listeners[id] = listener |
| 444 | return id |
| 445 | } |
| 446 | func unlisten(_ id: UUID) { listeners.removeValue(forKey: id) } |
| 447 | } |
| 448 | |
| 449 | /// The formats a camera is opened in, best first, and the frame rate to |
| 450 | /// ask for in each — held apart from AVFoundation so the rule can be |
| 451 | /// tested with numbers. |
| 452 | /// |
| 453 | /// Nearest 640 wide first (a call does not need more, and the encoder |
| 454 | /// scales down anyway), then nearest 30 frames a second without going |
| 455 | /// over, then the device's own order. The rate asked for is always one |
| 456 | /// the format supports: 30 where a range covers it, otherwise the |
| 457 | /// fastest rate at or under 30, otherwise the slowest the format offers. |
| 458 | /// An ATEM Mini offers 1080p at exactly 23.98, 24, 25, 29.97, 30, 50, |
| 459 | /// 59.94 and 60 — ranges of one rate each — and asking one of those for a |
| 460 | /// rate outside its range is an exception AVFoundation raises and WebRTC |
| 461 | /// swallows, leaving the camera at whatever rate it was on. |
| 462 | public struct CameraFormatChoice: Equatable, Sendable { |
| 463 | public struct Candidate: Equatable, Sendable { |
| 464 | public var width: Int |
| 465 | public var height: Int |
| 466 | /// Each supported range as (min, max) frames a second. |
| 467 | public var ranges: [ClosedRange<Double>] |
| 468 | public init(width: Int, height: Int, ranges: [ClosedRange<Double>]) { |
| 469 | self.width = width |
| 470 | self.height = height |
| 471 | self.ranges = ranges |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | /// The rate to run a format at, and whether it is a whole number WebRTC |
| 476 | /// can be given as-is. |
| 477 | public static func rate(for ranges: [ClosedRange<Double>], target: Double = 30) -> Double? { |
| 478 | guard !ranges.isEmpty else { return nil } |
| 479 | if ranges.contains(where: { $0.contains(target) }) { return target } |
| 480 | let under = ranges.map(\.upperBound).filter { $0 <= target } |
| 481 | if let best = under.max() { return best } |
| 482 | return ranges.map(\.lowerBound).min() |
| 483 | } |
| 484 | |
| 485 | /// The candidates' indexes, best first, one per distinct size and rate. |
| 486 | public static func rank(_ candidates: [Candidate], width target: Int = 640) -> [Int] { |
| 487 | var seen = Set<String>() |
| 488 | return candidates.indices.sorted { a, b in |
| 489 | let ca = candidates[a], cb = candidates[b] |
| 490 | let wa = abs(ca.width - target), wb = abs(cb.width - target) |
| 491 | if wa != wb { return wa < wb } |
| 492 | let ra = 30 - (rate(for: ca.ranges) ?? 0), rb = 30 - (rate(for: cb.ranges) ?? 0) |
| 493 | if abs(ra) != abs(rb) { return (ra >= 0 ? ra : 1000 - ra) < (rb >= 0 ? rb : 1000 - rb) } |
| 494 | return a < b |
| 495 | }.filter { |
| 496 | let c = candidates[$0] |
| 497 | let key = "\(c.width)x\(c.height)@\(rate(for: c.ranges) ?? 0)" |
| 498 | return seen.insert(key).inserted |
| 499 | } |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /// AVFoundation's camera, through WebRTC's capturer. |
| 504 | @MainActor final class AVCameraBackend: CameraBackend { |
| 505 | private var capturer: RTCCameraVideoCapturer? |
| 506 | private var observed: [NSObjectProtocol] = [] |
| 507 | private var listener: UUID? |
| 508 | #if os(macOS) |
| 509 | private var woke: NSObjectProtocol? |
| 510 | #endif |
| 511 | var devicesChanged: (@MainActor () -> Void)? |
| 512 | var trouble: (@MainActor () -> Void)? |
| 513 | /// How long an open may take before it counts as refused. A camera |
| 514 | /// that re-enumerates mid-open can leave the completion uncalled. |
| 515 | static let openTimeout: TimeInterval = 6 |
| 516 | |
| 517 | init() { |
| 518 | let watch = CameraWatch.shared |
| 519 | listener = watch.listen { [weak self] in self?.devicesChanged?() } |
| 520 | #if os(macOS) |
| 521 | woke = ( |
| 522 | NSWorkspace.shared.notificationCenter.addObserver( |
| 523 | forName: NSWorkspace.didWakeNotification, object: nil, queue: .main |
| 524 | ) { [weak self] _ in |
| 525 | MainActor.assumeIsolated { |
| 526 | CameraWatch.shared.refresh() |
| 527 | self?.trouble?() |
| 528 | } |
| 529 | }) |
| 530 | #endif |
| 531 | } |
| 532 | |
| 533 | func requestAccess() async throws { |
| 534 | for kind in [AVMediaType.video, .audio] { |
| 535 | let granted = await AVCaptureDevice.requestAccess(for: kind) |
| 536 | if !granted { |
| 537 | throw NSError( |
| 538 | domain: "Calls", code: 2, |
| 539 | userInfo: [NSLocalizedDescriptionKey: "Allow camera and microphone access in Settings to join."]) |
| 540 | } |
| 541 | } |
| 542 | } |
| 543 | |
| 544 | var devices: [CameraDevice] { |
| 545 | CameraWatch.shared.refresh() |
| 546 | return CameraWatch.shared.cameras |
| 547 | } |
| 548 | |
| 549 | private func formats(_ device: AVCaptureDevice) -> [AVCaptureDevice.Format] { |
| 550 | let all = RTCCameraVideoCapturer.supportedFormats(for: device) |
| 551 | let candidates = all.map { format -> CameraFormatChoice.Candidate in |
| 552 | let size = CMVideoFormatDescriptionGetDimensions(format.formatDescription) |
| 553 | return CameraFormatChoice.Candidate( |
| 554 | width: Int(size.width), height: Int(size.height), |
| 555 | ranges: format.videoSupportedFrameRateRanges.map { $0.minFrameRate...$0.maxFrameRate }) |
| 556 | } |
| 557 | return CameraFormatChoice.rank(candidates).map { all[$0] } |
| 558 | } |
| 559 | |
| 560 | func formatCount(_ id: String) -> Int { |
| 561 | guard let device = CameraWatch.shared.device(id) else { return 0 } |
| 562 | return formats(device).count |
| 563 | } |
| 564 | |
| 565 | func open(_ id: String, format index: Int, delegate: RTCVideoCapturerDelegate) async throws { |
| 566 | guard let device = CameraWatch.shared.device(id) else { |
| 567 | throw NSError( |
| 568 | domain: "Calls", code: 4, userInfo: [NSLocalizedDescriptionKey: "That camera is no longer available."]) |
| 569 | } |
| 570 | let ranked = formats(device) |
| 571 | guard !ranked.isEmpty else { |
| 572 | throw NSError( |
| 573 | domain: "Calls", code: 3, userInfo: [NSLocalizedDescriptionKey: "No camera is available."]) |
| 574 | } |
| 575 | let format = ranked[min(index, ranked.count - 1)] |
| 576 | let ranges = format.videoSupportedFrameRateRanges |
| 577 | let rate = CameraFormatChoice.rate(for: ranges.map { $0.minFrameRate...$0.maxFrameRate }) ?? 30 |
| 578 | let capture = capturer ?? makeCapturer(delegate: delegate) |
| 579 | // WebRTC takes a whole number of frames a second. For a rate that is |
| 580 | // not one (29.97), it is given the nearest, and the exact duration |
| 581 | // from the format's own range is set on the device afterwards. |
| 582 | let fps = max(1, Int(rate.rounded())) |
| 583 | let once = OSAllocatedUnfairLock(initialState: false) |
| 584 | do { |
| 585 | try await start(capture, device: device, format: format, fps: fps, once: once) |
| 586 | } catch { |
| 587 | // A failed or abandoned open may still finish later on the |
| 588 | // capturer's own queue and start delivering frames from this |
| 589 | // device. The capturer is cut loose — no delegate, stopped, not |
| 590 | // reused — so those frames reach nobody, and the next open gets a |
| 591 | // fresh one. |
| 592 | capture.delegate = nil |
| 593 | capture.stopCapture(completionHandler: {}) |
| 594 | capturer = nil |
| 595 | throw error |
| 596 | } |
| 597 | if Double(fps) != rate, |
| 598 | let range = ranges.first(where: { $0.minFrameRate <= rate && rate <= $0.maxFrameRate }) |
| 599 | { |
| 600 | let duration = rate == range.maxFrameRate ? range.minFrameDuration : range.maxFrameDuration |
| 601 | if (try? device.lockForConfiguration()) != nil { |
| 602 | device.activeVideoMinFrameDuration = duration |
| 603 | device.activeVideoMaxFrameDuration = duration |
| 604 | device.unlockForConfiguration() |
| 605 | } |
| 606 | } |
| 607 | } |
| 608 | |
| 609 | private func start( |
| 610 | _ capture: RTCCameraVideoCapturer, device: AVCaptureDevice, format: AVCaptureDevice.Format, |
| 611 | fps: Int, once: OSAllocatedUnfairLock<Bool> |
| 612 | ) async throws { |
| 613 | try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in |
| 614 | let finish: @Sendable (Error?) -> Void = { error in |
| 615 | let first = once.withLock { done -> Bool in |
| 616 | defer { done = true } |
| 617 | return !done |
| 618 | } |
| 619 | guard first else { return } |
| 620 | if let error { continuation.resume(throwing: error) } else { continuation.resume() } |
| 621 | } |
| 622 | capture.startCapture(with: device, format: format, fps: fps) { finish($0) } |
| 623 | DispatchQueue.main.asyncAfter(deadline: .now() + AVCameraBackend.openTimeout) { |
| 624 | finish( |
| 625 | NSError( |
| 626 | domain: "Calls", code: 6, userInfo: [NSLocalizedDescriptionKey: "The camera did not start."])) |
| 627 | } |
| 628 | } |
| 629 | } |
| 630 | |
| 631 | private func makeCapturer(delegate: RTCVideoCapturerDelegate) -> RTCCameraVideoCapturer { |
| 632 | let capture = RTCCameraVideoCapturer(delegate: delegate) |
| 633 | capturer = capture |
| 634 | let session = capture.captureSession |
| 635 | // A runtime error, or an interruption ending: WebRTC's capturer |
| 636 | // retries a runtime error once itself; these restart it again, rate |
| 637 | // limited by the director. |
| 638 | for name in [ |
| 639 | AVCaptureSession.runtimeErrorNotification, AVCaptureSession.interruptionEndedNotification, |
| 640 | ] { |
| 641 | observed.append( |
| 642 | NotificationCenter.default.addObserver(forName: name, object: session, queue: .main) { |
| 643 | [weak self] _ in |
| 644 | MainActor.assumeIsolated { self?.trouble?() } |
| 645 | }) |
| 646 | } |
| 647 | return capture |
| 648 | } |
| 649 | |
| 650 | func close() async { |
| 651 | guard let capturer else { return } |
| 652 | await capturer.stopCapture() |
| 653 | } |
| 654 | |
| 655 | deinit { |
| 656 | for token in observed { NotificationCenter.default.removeObserver(token) } |
| 657 | #if os(macOS) |
| 658 | if let woke { NSWorkspace.shared.notificationCenter.removeObserver(woke) } |
| 659 | #endif |
| 660 | if let listener { |
| 661 | Task { @MainActor in CameraWatch.shared.unlisten(listener) } |
| 662 | } |
| 663 | } |
| 664 | } |
| 665 | |
| 666 | /// The platform camera: AVFoundation under the recovery rules. |
| 667 | @MainActor final class CameraCapture { |
| 668 | static func make() -> ManagedCamera { ManagedCamera(backend: AVCameraBackend()) } |
| 669 | } |
| 670 | |
amadan