---
title: Subtrans
emoji: 🎥
colorFrom: blue
colorTo: indigo
sdk: docker
pinned: false
---

# Subtrans

A high-precision AI pipeline for automated subtitle generation and translation with context-aware self-correction.

[![System Architecture](architecture.png)](ARCHITECTURE.md)


---

## 🚀 Key Features

*   **Offline Transcription**: Uses local `faster-whisper` (`medium` model) with **Phonetic Bias** to correctly recognize technical terms (Naukri, NotebookLM).
*   **Precision Patching**: A dedicated LLM pass (Gemini) that detects and corrects low-confidence entities (names/brands) in the English source.
*   **Multi-Engine Translation**:
    *   **Google Translate (`deep-translator`)**: Fast, literal translation.
    *   **Groq Cloud LLM (`Llama 3.3 70B`)**: Idiomatic, natural conversational translations.
    *   **Gemini 1.5/2.5 Pro & Flash**: High-capacity translation using **Full-Context Batching** (entire file in one request) and **Glossary Support**.
*   **Content Isolation**: Secure `<l>` tag escrow for transcript content to prevent LLM instruction leakage.
*   **Automated Self-Correction Pass**: Post-translation quality audit using Gemini 3.1 Pro or Llama 3.3 70B.

---

## 🛠️ Setup & Installation

### 1. Prerequisites
Ensure you have **Python 3.10+** and **FFmpeg** installed on your system.

*   **FFmpeg (Windows)**: Install via Scoop (`scoop install ffmpeg`) or Chocolatey (`choco install ffmpeg`).
*   **FFmpeg (macOS)**: `brew install ffmpeg`
*   **FFmpeg (Linux)**: `sudo apt install ffmpeg`

### 2. Install Dependencies
Clone the repository and install the required dependencies:
```bash
pip install -r requirements.txt
```

### 3. Environment Configuration
Create a `.env` file in the root directory and add your Groq API Key:
```env
GROQ_API_KEY=your_groq_api_key_here
```

---

## 💻 How to Run

### Start the Application Server
Run the local FastAPI server using `uvicorn`:
```bash
uvicorn app.main:app --reload
```
Once running, open your browser and navigate to: `http://localhost:8000`

---

## 🧪 Running Tests & Validation

All tests are placed under the [app/tests/](app/tests/) directory and can be executed as follows:

### Run the Entire Test Suite
Verify pipeline logic, translators, and validation engine:
```bash
pytest app/tests
```

### Run Transcription & Model Accuracy Test
Verify transcription accuracy on a test clip using the Whisper `medium` model:
```bash
python app/tests/test_medium_accuracy.py
```

### Run Automated Pipeline Tests
Run a full end-to-end batch test on multiple videos with built-in logging and transcription reuse:
```bash
python app/tests/run_batch_tests.py
```
*Note: This script will prompt you to reuse previous transcriptions to save time and API costs.*

### Core Test Suite
Verify specific components (Translators, Precision Patch, Glossary):
```bash
pytest app/tests/test_precision_patch.py
pytest app/tests/test_glossary_and_context.py
```

---

## 📂 Project Structure
- `app/services/`: Core logic (Transcribe, Patch, Validate).
- `app/services/translators/`: Plugin-based LLM adapters.
- `app/tests/`: Integration tests and the `run_batch_tests.py` runner.
- `app/tests/experimental/`: Archive for research and one-off debugging scripts.
- `findings/`: Detailed development logs and architectural research results.