Modern Video Transcriber

A lightweight Flask application that ingests a YouTube URL, downloads the video's audio track with yt-dlp, converts it to 16 kHz mono WAV via ffmpeg, and sends the audio to Groq's Whisper API for high-quality speech-to-text output. The UI (Bootstrap + custom CSS) displays the full transcript alongside segment-level timestamps for quick scanning.

Features

• Paste any public YouTube link; the backend handles download, conversion, and cleanup.
• Segment timeline with start/end timestamps derived from the Whisper verbose JSON response.
• Simple Flask front end styled with Bootstrap 5 and a custom hero section.
• CLI helper (script.py) to transcribe arbitrary local audio files without the web UI.

Requirements

• Python 3.10+
• ffmpeg available on your PATH (configurable via FFMPEG_BINARY).
• Groq account + API key (environment variable recommended).

Quick Start

python -m venv .venv
.venv\Scripts\activate  # PowerShell on Windows
pip install -r requirements.txt
set FLASK_APP=app.py
set GROQ_API_KEY=your_api_key  # see note below
flask run

Then open http://127.0.0.1:5000 and submit a YouTube URL.

Important: The current implementation in script.py hardcodes an API key in _build_client. Replace that value with os.environ["GROQ_API_KEY"] (or similar) before deploying or sharing the project to keep credentials out of the codebase.

Environment Variables

• GROQ_API_KEY – Groq Whisper API key (should be kept secret).
• FLASK_SECRET_KEY – optional Flask session secret.
• FFMPEG_BINARY – path to an ffmpeg binary when not on PATH.

Project Structure

app.py            # Flask routes and yt-dlp/ffmpeg integration
script.py         # Groq Whisper helper + CLI entry point
templates/index.html
static/styles.css
downloads/        # temp input audio (auto-created)
processed/        # temp WAV output (auto-created)

CLI Usage

Transcribe a local file without the Flask UI:

python script.py path/to/audio.wav --language en --temperature 0.0

The script prints the verbose JSON transcription to stdout.

Troubleshooting

• Verify ffmpeg -version runs from the same shell; otherwise set FFMPEG_BINARY.
• Clean the downloads/ and processed/ folders if a previous run was interrupted.
• Set FLASK_DEBUG=1 for verbose error messages during development.

Roadmap Ideas

• Persist transcripts per user and allow downloads.
• Support direct file uploads instead of YouTube-only input.
• Swap the hardcoded Groq key for an environment-based configuration helper.