Subly

Subly is a Windows desktop application for creating subtitles from video. Import a video, transcribe its audio, translate and style the subtitles, then export them as a subtitle file or burn them into the video.

Features

• Drag-and-drop video import with an integrated preview
• Local transcription with Faster Whisper
• Cloud transcription with Groq, OpenAI, or Gemini
• Local translation with NLLB or cloud translation providers
• Subtitle timing, text, and style editing
• SRT, ASS, and VTT export
• Hardcoded subtitle rendering with FFmpeg
• Local, secure storage for API keys

Requirements

• Windows 10 or later
• Python 3.10 or later
• FFmpeg and FFprobe available on PATH
• libmpv (recommended) or VLC for video preview

Local transcription and translation models require additional disk space and are downloaded when first used.

Installation

git clone https://github.com/onlyv4ns/subly.git
cd subly
py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip
pip install -r requirements.txt

For cloud providers, copy the example environment file and add only the keys you need:

Copy-Item .env.example .env

GROQ_API_KEY=
OPENAI_API_KEY=
GEMINI_API_KEY=
HF_TOKEN=

You can also configure provider keys from the application settings.

Usage

Start Subly from the project root:

python src/subly/main.py

Then follow the four-step workflow:

1. Import a video.
2. Transcribe its audio with a local or cloud provider.
3. Style and translate the generated subtitles.
4. Export to SRT, ASS, or VTT, or render the subtitles into the video.

Development

Install the development dependencies and run the tests:

pip install -r requirements-dev.txt
pytest

Technology

• CustomTkinter and TkinterDnD for the interface
• Faster Whisper for local speech recognition
• CTranslate2 and NLLB for local translation
• FFmpeg, mpv, and VLC for video processing and preview
• pysubs2 for subtitle file generation

License

This project is licensed under the MIT License.