Files
ten31-transcripts/Ten31Transcripts/Visual/VisualCapture.swift
T
Grant Gilliam 880b56e426 Wire visual capture into the recording lifecycle (failure-isolated)
Visual capture now runs alongside audio: on call start the session picks the
app's adapter, captures the call window on the SAME monotonic clock as the audio
(AudioRecorder.sharedT0Host), and on stop writes visual_timeline.json and hands
the backend the visual segments with mic-VAD self-spans merged. Any visual
failure (no adapter, no window, Screen Recording denied) leaves the session
recording audio-only — the proven path is never blocked or broken.

- CallDetector now emits DetectedCall{app, bundleID, windowID}: the exact
  CGWindowID of the matched Meet browser window (native apps → nil → largest).
- VisualCapture wraps VisualObserver + AdapterRegistry, writes visual_timeline.json.
- AudioRecorder.sharedT0Host() exposes the shared t0 for frame alignment.

Hardened per a 3-lens adversarial review (concurrency / failure-isolation /
data-flow), all 6 confirmed findings fixed:
- P0 (critical): startVisual could adopt a stale capture into a DIFFERENT session
  (cross-session SCStream leak + visual_timeline.json written to the wrong
  folder). Now gated on session identity — generation + recorder ===, still
  .recording — with fail-closed adoption; otherwise the stream is cancelled.
- P1: observer captured the browser's largest window, not the detected Meet
  window. Now targets the exact CGWindowID (pickWindowIndex, unit-tested),
  largest-area only as fallback.
- P2: a startVisual orphaned by a concurrent stop could leak a stream on quit.
  inFlightVisual is registered before the await and drained in prepareForTermination.
- P3: trailing visual gap/segment ends could exceed duration_sec. Clamped in
  VisualCapture (clampSegments/clampGaps, unit-tested).
- P4: capture pixel size used NSScreen.main scale; now uses the scale of the
  display actually hosting the window (OCR clarity on secondary displays).
- VisualObserver.stop() bounds stopCapture() with a 3s timeout (mirrors audio) so
  a wedged stream can't hang finalization.

25/25 XCTest pass. Live validation on real calls still pending.
2026-06-06 10:18:52 -05:00

84 lines
4.0 KiB
Swift

import Foundation
import CoreGraphics
/// Owns the visual side of one recording session: picks the app's adapter, runs a
/// `VisualObserver` over the call window, and on stop writes `visual_timeline.json`
/// and returns the speaker segments for the backend hand-off.
///
/// Strictly best-effort: if there's no adapter for the app, or the window can't be
/// captured, the session simply records audio-only visuals never block or break
/// the proven audio path. `init?` returns nil when the app has no visual adapter.
@available(macOS 13.0, *)
final class VisualCapture {
let app: CallDetector.DetectedApp
private let adapter: any AppAdapter
private let observer: VisualObserver
init?(app: CallDetector.DetectedApp, bundleID: String, windowID: CGWindowID?, t0Host: Double) {
guard let adapter = AdapterRegistry.adapter(for: app) else { return nil }
self.app = app
self.adapter = adapter
self.observer = VisualObserver(bundleID: bundleID, windowID: windowID, adapter: adapter,
t0Host: t0Host, fps: adapter.preferredFPS)
}
/// Start window capture. Throws if the window isn't capturable (no window yet,
/// Screen Recording denied) the caller catches and falls back to audio-only.
func start() async throws {
try await observer.start()
}
/// Stop and discard capture without writing anything (used when the session
/// ends before capture was fully adopted).
func cancel() async {
_ = await observer.stop()
}
/// Clamp segment ends to the audio duration; drop any that become empty. Keeps
/// `visual_timeline.json` internally consistent and never sends the backend a
/// segment longer than the audio. (`duration <= 0` passthrough.)
static func clampSegments(_ segs: [VisualTimeline.Segment], to duration: Double) -> [VisualTimeline.Segment] {
guard duration > 0 else { return segs }
return segs.compactMap { s in
let end = min(s.end, duration)
guard end > s.start else { return nil }
return .init(start: s.start, end: end, name: s.name, confidence: s.confidence, source: s.source)
}
}
static func clampGaps(_ gaps: [VisualTimeline.Gap], to duration: Double) -> [VisualTimeline.Gap] {
guard duration > 0 else { return gaps }
return gaps.compactMap { g in
let end = min(g.end, duration)
guard end > g.start else { return nil }
return .init(start: g.start, end: end, reason: g.reason)
}
}
/// Stop capture, fold in the mic-VAD self spans, write `visual_timeline.json`
/// into the session folder, and return the merged segments for `label-merge`.
func finish(selfSpans: [VADSpan], selfName: String,
sessionId: String, t0Unix: Double, durationSec: Double,
folder: URL) async -> [VisualTimeline.Segment] {
observer.addSelfSpans(selfSpans, selfName: selfName)
let (rawSegments, rawGaps) = await observer.stop()
// The observer stops slightly after audio fixes `durationSec`, so a trailing
// gap/segment can run past it. Clamp ends so the JSON is internally consistent
// (and we never hand the backend a segment longer than the audio).
let segments = Self.clampSegments(rawSegments, to: durationSec)
let gaps = Self.clampGaps(rawGaps, to: durationSec)
let names = Set(segments.map { $0.name })
let participants = names.sorted().map {
VisualTimeline.Participant(name: $0, isSelf: $0 == selfName ? true : nil, aliases: nil)
}
let timeline = VisualTimeline(
sessionId: sessionId, app: app.label, adapterVersion: adapter.adapterVersion,
t0Unix: t0Unix, durationSec: durationSec, fpsSampled: adapter.preferredFPS,
selfName: selfName, participants: participants, segments: segments, visualGaps: gaps)
try? timeline.write(to: folder.appendingPathComponent("visual_timeline.json"))
return segments
}
}