fix(recorder): camera flip no longer kills the record button or drops the H.264 pin (iOS)

[morepriyam]

Fixes the TestFlight build 31 regression: flipping the camera on iOS permanently killed the record button, and (silently) dropped the H.264 codec pin for all post-flip clips. Full root-cause analysis in #153.

The one-line version

#150 correctly stopped gating the mic on cameraReady — but that gate flip was what made a camera flip rebuild the video output and restart the session. Two behaviors were secretly riding that accidental restart, and build 31 (main @ 82e3b95, first build with #150) exposed both.

Changes

1. flipCamera()'s cameraReady reset is now Android-only. It exists for CameraX's torch-mid-rebind crash (Android parity: first device-testing wave — recorder fixes, call detection, release hygiene #133), and CameraX re-fires onStarted per bind so it re-arms there. On iOS the flip is an input swap inside beginConfiguration/commitConfiguration on a running session — didStartRunningNotification never fires (verified in HybridCameraSession.swift: the listener maps to that notification, and start() early-returns on isRunning), so the reset could never re-arm and permanently disabled the record gestures. iOS's zoom/torch props already bind ungated (ba7647b), so the reset served no purpose there. This mirrors the existing platform scoping pattern.

2. The H.264 pin re-applies per connection, not per output instance. Natively the codec lands per-connection (output.setOutputSettings(settings, for: connection)), and every reconfigure — flip, enableAudio rebuild — forms a new connection, killing the pin. The pin effect now keys on a connection epoch bumped from <Camera onConfigured> (VisionCamera's documented "connections are formed" hook), which fires after the new connection exists — the only ordering that can't lose the pin to an async reconfigure landing later. The existing bounded retry still rides any residual race; fail-open behavior (worst case: one HEVC clip) is unchanged.

Verification

• tsc --noEmit clean, eslint clean, jest 122 passed
• Device checklist:
  • iOS: open recorder → flip → record button works immediately; flip back → still works
  • iOS: record a clip after a flip → probe shows h264 (not hevc)
  • iOS: mute toggle mid-session still rebuilds output cleanly and clips stay h264
  • Android: flip front/back with torch — no No flash unit crash (the Android parity: first device-testing wave — recorder fixes, call detection, release hygiene #133 guard is intact)

Fixes #153

[Copilot]

Pull request overview

This PR fixes an iOS recorder regression where flipping the camera could permanently disable recording interactions and silently revert post-flip clips to HEVC by ensuring iOS flip no longer relies on a cameraReady reset and by re-applying the H.264 codec pin per newly formed video connection.

Changes:

• Makes flipCamera()’s cameraReady reset Android-scoped to avoid permanently disabling record gestures on iOS.
• Re-keys the iOS H.264 pin logic from “video output identity” to a “connection epoch” bumped via <Camera onConfigured>.
• Wires a new onSessionConfigured callback from the recorder hook into the <Camera onConfigured> event.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/features/recorder/use-recorder.ts	Adds connection-epoch-based H.264 pinning and scopes cameraReady reset during camera flips.
src/app/recorder.tsx	Wires <Camera onConfigured> to the recorder hook to bump the connection epoch after reconfigures.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

Suppressed comments (1)

src/features/recorder/use-recorder.ts:557

• onSessionConfigured always bumps connectionEpoch, even on non-iOS platforms where connectionEpoch is never read (the pin effect is iOS-only). This introduces extra state updates/renders on Android (and any other platform) every time VisionCamera emits onConfigured, without any functional benefit.

    onCameraReady: () => setCameraReady(true),
    // Wire to <Camera onConfigured>: fires whenever the session's connections are (re)formed —
    // cold open, enableAudio output rebuild, camera flip. Bumping the epoch re-arms the H.264
    // pin for the NEW video connection (the codec is applied per-connection natively, so it
    // dies with the old one on every reconfigure).
    onSessionConfigured: () => setConnectionEpoch((prev) => prev + 1),