git:20260812.1d277fb to git:20260902.786198b

# Timeline Studio — Full Product Reference

Canonical URL: https://video-editor.ai-creator.top/

GitHub: https://github.com/MartinDelophy/ai-video-editor

License: MIT

## Definition

Timeline Studio is a free, open-source, local-first AI video editor that runs in a desktop web browser. It opens directly into a multi-track editing workspace for importing local media, generating narration and captions, editing visual clips, previewing a composition and exporting video.

## AI voiceover

- Chinese and mixed Chinese/English: Hojo TTS Light 80M FP16 WebGPU with two built-in female reference voices (晴岚, 若溪).

- English: Kokoro 82M v1.0 ONNX q8 on WASM.

- Additional browser Piper voices: German, Spanish, French, Italian and Brazilian Portuguese.

- Generated speech is inserted at the current playhead as a voiceover clip.

- Browser microphone recording is also available after user permission.

## Automatic captions

- Default recognition model: Whisper small q8 ONNX.

- Execution: WASM worker for subtitle stability.

- Timing: coarse recognition boundaries are adjusted toward nearby source-audio energy.

- Chinese cleanup: conservative contextual correction for high-confidence homophone mistakes.

- Caption text and segments are edited in the right-side caption context panel.

- Global caption placement and styling remain in the caption tool.

- Preview and export share scale-aware caption layout.

## Visual editing

- Visual clips support scale, horizontal position, vertical position, rotation and opacity keyframes.

- Keyframes can capture all transform properties together or key individual properties independently.

- Supported masks: rectangle, rounded rectangle and circle, with position, size, feathering and inversion controls where applicable.

- Masks stay in canvas coordinates while the visual media transforms behind them.

- Video speed is clip-scoped and uses the same source-time mapping for preview, timeline duration, keyframes and export.

- Extracted source audio can stay linked to its video or use independent timing.

## Timeline

- Visual, sticker, caption, source-audio, voiceover and music tracks.

- Clip operations include selection, moving, splitting, duplication, resizing and deletion.

- Track operations include visibility and locking.

- Multiple generated voiceover or caption lanes are created when clips overlap.

- Timeline geometry remains time-accurate across zoom levels.

## Browser vision

- YOLOS tiny q8 ONNX detects subjects.

- MODNet q8 ONNX provides portrait matting.

- Subject geometry supports smart crop and caption avoidance.

- Video analysis produces timestamped samples across the clip instead of reusing only the first frame.

- Model inference is precomputed and bounded rather than performed inside the real-time export loop.

## Talking portrait

- JoyVASA ONNX converts audio into motion coefficients.

- LivePortrait performs neural rendering on WebGPU.

- 256px mixed-FP16 mode is intended for faster preview.

- 512px mixed-FP16 mode is intended for quality output and can be slow on current browser GPUs.

- Sparse neural keyframes are interpolated for encoded output.

## Export

- Export controls include resolution, frame rate, codec and quality.

- Available resolution choices include 720p, 1080p, 1440p and 2160p.

- Available frame-rate choices include 30fps and 60fps.

- MP4 is produced when the browser supports the required native or browser-side conversion path.

- WebM is used as a fallback when MP4 conversion is unavailable or fails.

- Export renders the project canvas and mixes active audio tracks in the browser.

## Privacy and networking

- Images, video and audio selected for a project are processed in the browser.

- Model and runtime files can be downloaded from configured third-party hosts.

- A service worker caches supported application and model assets for repeat use.

- Interface language and other preferences may be stored in browser local storage.

- Timeline Studio should be described as local-first, not as making zero network requests or bundling every model offline.

## Supported interface languages

## Technology

React 19, Vite 6, ONNX Runtime Web, WebAssembly, WebGPU, MediaRecorder, browser Canvas APIs and FFmpeg WASM support.

## Official factual pages

- https://video-editor.ai-creator.top/features/

- https://video-editor.ai-creator.top/how-it-works/

- https://video-editor.ai-creator.top/faq/

- https://video-editor.ai-creator.top/privacy/

- https://video-editor.ai-creator.top/about/