# Python Whisper Live Transcription & Translation

A real-time, low-latency audio transcription and translation tool utilizing OpenAI's Whisper (via `mlx-whisper` for Apple Silicon optimization), Silero VAD for speech detection, and Helsinki-NLP's Opus-MT models for translation.

## Features
- **Live Transcription:** Real-time speech-to-text with automatic language detection.
- **On-the-fly Translation:** Bridge translations to English and then to target languages (Spanish, Arabic, French, etc.).
- **Voice Activity Detection (VAD):** Intelligent audio buffering using Silero VAD to process only actual speech.
- **Apple Silicon Optimized:** Uses MLX for high performance on Mac (MPS).
- **Background Ingestion:** Optional background thread to send JSON payloads to a remote server.
- **Configurable:** Command-line parameters to select languages, devices, and ingestion.

## Installation

1. **Clone the repository:**
   ```bash
   git clone <repository-url>
   cd pythonwhisper
   ```

2. **Install dependencies:**
   Ensure you have Python 3.9+ and the required libraries:
   ```bash
   pip install mlx-whisper numpy sounddevice torch requests transformers silero-vad
   ```
   *Note: On Apple Silicon, ensure `mlx` and `torch` with MPS support are correctly installed.*

## Usage

Run the script using `python3 transcribe.py` with optional flags.

### Common Commands
- **List available audio devices:**
  ```bash
  python3 transcribe.py -l
  ```
- **Caption system audio (speakers) using a loopback device:**
  ```bash
  python3 transcribe.py --loopback -es
  ```
- **Transcribe and translate to Spanish (screen only):**
  ```bash
  python3 transcribe.py -es
  ```
- **Enable Spanish, Arabic, and French with English bridging, and send to server:**
  ```bash
  python3 transcribe.py -es -ar -fr -en -i
  ```
- **Use a specific input device (e.g., index 3) and translate to Spanish:**
  ```bash
  python3 transcribe.py -d 3 -es
  ```

### Arguments
- `-es`: Enable Spanish translation.
- `-en`: Enable English (shows original if detected, or bridged if not).
- `-ar`: Enable Arabic translation.
- `-fr`: Enable French translation.
- `-i`, `--ingest`: Enable data transmission to the remote server.
- `-l`, `--list-devices`: Show available audio devices and exit.
- `-d`, `--device [ID]`: Input device index (bypasses selection prompt).
- `--loopback`: Automatically select a loopback device (e.g., BlackHole, Stereo Mix) to caption system audio.
- `-q`, `--quantize`: Use 4-bit quantized Whisper model for faster transcription (Strategy 3).
- `-s`, `--stream`: Enable real-time streaming transcription/draft mode (Strategy 1).
- `-c`, `--context`: Enable prompt caching/rolling context to help the model maintain sentence continuity across chunks.
- `--lang [CODE]`: Hardcode the source language (e.g., `en`, `es`) to bypass automatic language detection for faster processing.
- `--silence [MS]`: Set the minimum silence duration in milliseconds to end a chunk. Defaults to 1000ms. Increase to force longer sentences before translation.
- `--max-buffer [SEC]`: Maximum buffer duration in seconds before forcing a flush (default: 20).
- `--channels [N]`: Number of input channels (default: 1).
- `--pick-channel [0|1]`: If stereo, select channel 0 (Left) or 1 (Right) to focus transcription.
- `--filter-lang`: If used with `--lang`, discards segments that do not match the target language.

---

## Technical Note: Universal Translation Models

While the current implementation uses specialized, per-language models from the **Helsinki-NLP Opus-MT** project (e.g., `opus-mt-en-es`, `opus-mt-en-ar`), there is an alternative approach: **Universal Models**.

### Universal Model Alternative (e.g., Meta's NLLB-200)
The current per-language model approach is highly accurate and memory-efficient if you only need 1 or 2 target languages. However, if you require support for many languages simultaneously, loading multiple specialized models can consume significant RAM/VRAM.

We have the option to switch the translation engine to a single, universal model such as **NLLB-200 (No Language Left Behind)**:
- **Model ID:** `facebook/nllb-200-distilled-600M`
- **Benefits:**
    - Supports over **200 languages** in a single model.
    - Simplified code: no need to load/manage multiple model objects.
    - More efficient for complex multilingual environments.
- **Trade-off:** Slightly higher memory footprint for the single model compared to a single specialized model, but more efficient than 3+ specialized models.

If you wish to switch to a universal model, the `transcribe.py` logic can be updated to use a single `M2M100` or `NLLB` pipeline instead of the current `MarianMT` loop.