[codex] Fix native Windows recording pause

[EtienneLescot]

Summary

Adds pause/resume support for native Windows WGC recording so the existing recording pause control works when the app uses the Windows native helper.

What changed

• Exposes native Windows pause/resume IPC calls through preload and renderer types.
• Enables the pause control while a native Windows recording is active and tracks paused duration in the recorder hook.
• Teaches the WGC helper to accept pause and resume commands, suspend video/audio output while paused, and compact encoded timestamps after resume.
• Compacts editable cursor telemetry across native Windows paused ranges before writing cursor metadata.
• Makes the Windows helper build prefer the real SDK um/x64 libraries before local compatibility libs so cursor-sampler links correctly on native Windows dev environments.

Validation

• npm run build-vite
• npm run build:native:win
• npx biome check electron/electron-env.d.ts electron/ipc/handlers.ts electron/preload.ts src/hooks/useScreenRecorder.ts scripts/build-windows-wgc-helper.mjs

Summary by CodeRabbit

• New Features

  • Pause and resume native Windows screen recordings — temporarily stop audio, video and cursor capture without ending the recording session.

• Improvements

  • Pauses are tracked so timeline and recorded timestamps remain consistent across pause/resume.
  • Better handling when pausing/resuming to avoid dropped frames or hung stop sequences.

• Bug Fixes

  • Surface pause/resume errors to the user via toast notifications.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: d4970d38-c4be-41be-a5f1-bc3235dedd82

📥 Commits

Reviewing files that changed from the base of the PR and between ca826d9 and a50835e.

📒 Files selected for processing (2)

• electron/native/wgc-capture/src/main.cpp
• src/hooks/useScreenRecorder.ts

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📝 Walkthrough

Walkthrough

This PR adds pause/resume functionality to Windows native screen recording across renderer APIs, React hooks, main-process IPC with cursor pause telemetry, native audio mixer pause gating, WGC capture synchronization, and Windows build helper updates.

Changes

Native Windows Recording Pause/Resume

Layer / File(s)	Summary
Renderer-exposed pause/resume interface electron/electron-env.d.ts, electron/preload.ts	Exposes pauseNativeWindowsRecording() and resumeNativeWindowsRecording() methods returning Promises with { success: boolean; error?: string } through the renderer bridge.
React hook pause/resume integration src/hooks/useScreenRecorder.ts	useScreenRecorder now tracks paused state in native Windows recording handles, allows pausing during active native Windows capture, initializes paused:false on start, updates pause timing bookkeeping on toggle, and adjusts macOS webcam size fields to 0.
IPC handlers and cursor pause tracking electron/ipc/handlers.ts	Adds pause-native-windows-recording and resume-native-windows-recording IPC handlers; tracks cursor pause start times, accumulated pause ranges, and paused state; implements completeNativeWindowsCursorPauseRange(); integrates tracking into start/stop/error flows and compacts cursor telemetry for write-out.
AudioMixer pause state and gating electron/native/wgc-capture/src/audio_sample_utils.h, electron/native/wgc-capture/src/audio_sample_utils.cpp	Adds paused_ state and setPaused(bool) to AudioMixer; clears queued audio when pausing, drops incoming samples while paused, and updates mixer thread wait predicate to require not-paused before processing.
WGC capture pause/resume coordination electron/native/wgc-capture/src/main.cpp	Introduces CaptureControl for stop/pause synchronization; replaces stdin stop-only loop with readCaptureCommands handling pause/resume and emitting JSON events; gates frame callback on pause; subtracts paused duration from encoded timestamps; rewires writer/encoder waits and shutdown to use unified control logic.
Windows SDK library path resolution scripts/build-windows-wgc-helper.mjs	Adds findWindowsSdkUmLibDir() to detect latest Windows SDK um/x64 lib directory; conditionally prepends SDK lib path to LIB in generated .cmd and ensures gdiplus.lib is present when preparing compatibility libs.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• siddharthvaddem/openscreen#314: Updates to src/hooks/useScreenRecorder.ts for pause/resume state tracking and togglePaused flow used by the UI.
• siddharthvaddem/openscreen#217: Original Windows native capture introduction with IPC, cursor pipeline, and electron/native/wgc-capture code that this PR extends.
• siddharthvaddem/openscreen#573: Overlap on cursor clipping and related telemetry handling in the IPC and export paths.

Suggested reviewers

• siddharthvaddem
• FabLrc

Poem

pause the frames, hush the mic, a tiny breather taken
timestamps shrink the sleeping seconds, nothing’s mistaken
cursor pauses logged like footprints in the snow ❄️
audio drains cleared—resume, and let the pixels flow 🎬
lowkey elegant, low-res caffeine-fueled code awaken

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 4.35% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	Title clearly summarizes the main feature: adding pause/resume support to native Windows WGC recording, matching the primary objective of the changeset.
Description check	✅ Passed	PR description covers the motivation, what changed, and validation steps. However, it doesn't follow the template structure with explicit sections like Description, Type of Change, or Related Issue(s).
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[siddharthvaddem]

LGTM — conflict resolved, lint/typecheck/tests green locally.