🎻 Violin

Open-source Video Translation Skill.

🌐 Live demo · 📝 Blog post · 📜 MIT License

Upload a video. Violin transcribes the speech, translates it, synthesizes a native-sounding voice-over in the target language, and remuxes it back into the video — fully aligned, with optional SRT subtitles.

Available as a CLI, a FastAPI web app, and a Claude Code skill.

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✨ Features

• 33 target languages with handpicked native-speaker voices for the 16 most-used ones (Cartesia Sonic 3 + ElevenLabs)
• In-video Q&A — ask questions about any moment in the dubbed video; answers use nearby subtitles plus sampled frames
• Natural-language voice picker — describe the voice you want, an LLM picks from the catalog
• 6 style profiles (experimental) — standard / kids / academic / casual / storyteller / news
• Pluggable stack — Together / OpenAI / ElevenLabs interchangeable for every stage, one YAML

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🚀 Quick start

Try it without installing anything

The live demo runs at https://www.violin-ai.com — drop a short clip in, get a dubbed video out in a few minutes.

Run locally

Requires Python 3.10+ and ffmpeg on PATH.

curl -LsSf https://astral.sh/uv/install.sh | sh   # install uv if you don't have it
uv tool install violin                            # recommended — faster, isolated
# or: pip install violin                          # if you'd rather install into your current Python env

export TOGETHER_API_KEY=...                       # get one at https://api.together.ai (add to ~/.zshrc to persist)

Three ways to use it:

1. CLI — translate one file:

violin lecture.mp4 lecture_zh.mp4 --language Chinese

2. Web app — full REST API + browser UI:

violin-api
# → http://127.0.0.1:8000           (browser UI)
# → http://127.0.0.1:8000/docs      (interactive API docs)

3. Claude Code skill — invoke from any Claude Code session:

violin --install-skill          # one-time: copies the skill into ~/.claude/skills/
claude
> please use the violin skill to translate path/to/video.mp4 into Chinese

Run from source (for hacking on the pipeline)

git clone https://github.com/shang-zhu/violin.git
cd violin
uv sync
cp .env.example .env             # then fill in TOGETHER_API_KEY
uv run main.py lecture.mp4 lecture_zh.mp4 --language Chinese

To use the violin / violin-api commands globally while edits to your local source reflect immediately, install editable:

uv tool uninstall violin     # if you've installed the PyPI version
uv tool install --editable .

After this, violin / violin-api run from your local checkout — edit any file and the next invocation picks it up; no rebuild needed. To switch back to PyPI: uv tool uninstall violin && uv tool install violin.

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📝 To Do List

• [-] support voice cloning.
• [-] lip sync generation.

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🎬 How Violin works