Recordings longer than ~10 minutes silently fail to save (#616). The
renderer buffers the whole WebM as a Blob[], then on stop makes several
in-memory copies (fixWebmDuration -> arrayBuffer -> Buffer.from) before
writing. A long 1080p recording duplicates hundreds of MB several times
in the renderer, exceeds Electron's memory limit, and the renderer
crashes silently with no file saved.
Two changes:
1. Stream chunks to disk (originally @Amanuel2x's contribution in #617).
Open an fs.WriteStream in the main process at recording start and send
each ~1s ondataavailable chunk straight to disk over two new IPC calls
(open-recording-stream, append-recording-chunk), so the renderer never
holds more than a single chunk. A full in-memory fallback is preserved
for environments where the IPC stream cannot open.
2. Patch the WebM Duration header on disk after the stream closes. Browser
MediaRecorder writes WebM with no Duration element, so streamed files
save with duration=N/A and the editor's seek bar, timeline, and any
scrub/trim break. A new electron/recording/webm-duration.ts module
rewrites the Duration element, writing to a temp file and renaming in
place so a crash mid-write cannot corrupt the recording.
Streaming is opt-in: the screen recorder and the browser-only webcam
recorder stream to disk; native-capture webcam sidecars (Windows, macOS)
keep buffering in-memory, since their finalize path reads the recorder
blob directly to attach the webcam track.
Verified: tsc --noEmit clean; biome clean; vitest 166/166.
Closes#616
Supersedes #617
Co-Authored-By: Amanuel <amanuel@localboostnetworking.com>
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
neurot1cal
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