Groq Subtitle Generator (Project SubLingo)

The Groq Subtitle Generator (Project SubLingo) is a demo that showcases Groq in action through high-speed transcription and translation, allowing users to generate burned-in subtitles across languages in just seconds. Users can upload a video in any of the 50+ supported languages, choose the same or a different language for subtitles, review the transcription, and watch the magic unfold.

Once a video is uploaded, FFmpeg converts it to a WAV audio file, which is then passed to the Video Processing Service. This audio is transcribed using OpenAI’s Whisper Large V3-turbo model, powered by Groq. Users can edit individual segments to ensure accuracy. If translation is selected, the content is then translated using the Qwen3-32B model through the Groq API. The final subtitles are formatted as an SRT file and rendered onto the video using FFmpeg to produce the final output. Here is a sample video file to test the demo out!

updatedsubtitlegen.mp4

Features

• Multi-language Support: 50+ languages with automatic detection
• Ultra-Fast Processing: Whisper API powered by Groq for lightning-fast transcription
• Advanced Translation: Qwen3-32b by Groq for accurate multilingual translation
• Video Processing: Supports MP4, MOV, AVI
• Burned-in Subtitles: Create videos with permanently embedded subtitles
• Edit Before Translation: Review and edit transcription for perfect accuracy

🛠️ Tech Stack

Backend

• FastAPI
• Groq API
• FFmpeg
• Pydantic

Frontend

• Next.js 15
• TypeScript
• Tailwind CSS
• Lucide React

🚀 Quick Start

Prerequisites

• Python 3.8+
• Node.js 18+
• FFmpeg installed
• Groq API key (get free access at groq.com)

Install FFmpeg

macOS:

brew install ffmpeg

Ubuntu/Debian:

sudo apt update
sudo apt install ffmpeg

Windows: Download from https://ffmpeg.org/download.html

🎯 Setup & Run

Choose your preferred setup method:

Option 1: Automated Setup (Recommended)

Easy one-command setup:

1. Clone and setup everything:

   git clone <repository-url>
   cd groq-subtitle-generator
   chmod +x setup.sh start.sh
   ./setup.sh

2. Add your Groq API key:

   # Edit backend/.env and add your API key
   GROQ_API_KEY=your_groq_api_key_here

3. Start the application:

   ./start.sh

The scripts handle all dependency installation, virtual environment setup, and server management automatically!

Option 2: Manual Setup

For those who prefer manual control:

1. Clone the repository:

   git clone <repository-url>
   cd groq-subtitle-generator

2. Setup Python environment:

   cd backend
   python3 -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate
   pip install -r requirements.txt
   cd ..

3. Setup Node.js dependencies:

   npm install

4. Create environment file:

   # Create backend/.env file
   cat > backend/.env << 'EOF'
   GROQ_API_KEY=your_groq_api_key_here
   GROQ_MODEL=qwen/qwen3-32b
   GROQ_WHISPER_MODEL=whisper-large-v3
   EOF

5. Start backend server:

   cd backend
   source venv/bin/activate
   python main.py

6. In a new terminal, start frontend:

   npm run dev

That's it! 🎉 The application will be available at http://localhost:3000

⚙️ Configuration Options

The backend/.env file supports these settings:

# Required
GROQ_API_KEY=your_groq_api_key_here

# Model Selection (optional)
GROQ_MODEL=qwen/qwen3-32b
GROQ_WHISPER_MODEL=whisper-large-v3  # Options: whisper-large-v3, whisper-large-v3-turbo, distil-whisper-large-v3-en

🎬 Usage Workflow

1. 📤 Upload Video: Drag and drop or select a video file
2. 🌐 Configure Languages:
   • Source language
   • Target language for subtitles
3. 🎵 Transcription: Whisper transcribes the audio with timestamps
4. ✏️ Edit & Review: Review and edit transcription for perfect accuracy
   • Edit individual segments with timestamps
   • Ensure quality before translation
5. 🔄 Translation: Qwen3-32b translates to your target language
6. 🎬 Generation: Create subtitled video with burned-in subtitles
7. 📥 Download: Get your subtitled video

🔍 Troubleshooting

Scripts not executable?

chmod +x setup.sh start.sh

FFmpeg not found? Make sure FFmpeg is installed and available in your PATH.

API key issues? Ensure your Groq API key is correctly set in backend/.env.

Port conflicts? The app uses ports 3000 (frontend) and 8000 (backend). Make sure these are available.

🙏 Acknowledgments

• Groq for ultra-fast AI inference
• FFmpeg for video processing
• FastAPI & Next.js for the frameworks

👨‍💻 Author

Created by Krish Desai, AI Applications Engineer Intern at Groq.
Connect with him on X (formerly Twitter) and LinkedIn.

📄 License

This project is licensed under the MIT License.