Desktop MP4 export renders frames from a hidden BrowserWindow via
capturePage, pipes PNGs to a bundled ffmpeg (libx264/yuv420p/+faststart),
and writes the file through an atomic temp-file swap. It shares scene
validation (shared/renderValidation.cjs) and the render.html renderer with
the standalone Puppeteer server, which is hardened in parallel.
Render worker & main (electron/):
- abortable render loop with an inactivity watchdog and cancel plumbing
- atomic temp-file + rename so a cancel/failure never truncates a
pre-existing target (#7); stdin EPIPE / early-exit / backpressure-hang
handled (#8)
- HiDPI frames normalized to canvas size (#10); odd dimensions padded to
even (#13, also server); backgroundThrottling disabled (#12)
- reject canvases larger than the display (#11); single-render guard;
isolated render session that blocks network requests (#5)
Tests:
- Electron harnesses (scripts/verify-*.cjs) for capture, export, cancel,
timeout, assets, background, capture-fidelity, resolution, odd-dims,
aggregated by verify-desktop-render.cjs
- server smoke + e2e and shared validation unit tests
- headless hook (src/devtools/headless.ts) to run the in-app suite under
browser/electron hosts; pixel-diff util + capture fixtures (test/)
- dev_docs plans: integration, fixes (#7-#13), and the e2e/capture strategy
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- background video layer (document-level), syncs to playhead in editor and fullscreen
- playback in/out brackets on the scrub ruler; i/o set them, r rewinds to in-point
- togglePlay, tick, fullscreen loop, WebM + server FFmpeg export all honor [in, out]
- top-level mask layers cascade over everything below until a group boundary
- fullscreen preview slaves localTime to the bg video so it stops stuttering
- welcome "new project" now actually loads a blank scene (was a no-op)
- default canvas background hardened to white via normalizeScene
- new keyframe button (+) in the name-spacer, backspace/delete removes selected kfs
- drag-end auto-selects the created/shifted keyframe so the path is visible
- animation path updates live during drag and spans every selected keyframe
- track rows show an icon per asset kind (rect/circle/image/text/polygon/freeform)
- default mask mode is negative, buttons read − then +
- sticky track-name columns raised above playhead/brackets; orange bracket styling
- tests for playback range, blank scene, mask defaults, cascading top-level masks
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>