Speech-to-Text Studio
A high-performance Speech-to-Text transcription and multi-language translation web application. Features client-side Web Audio API extraction (processes 1.4GB video to 16kHz WAV in <1s), an environment-aware hybrid engine (local faster-whisper CTranslate2 GPU execution locally, Groq Cloud API in production), real-time SSE line streaming, and DeepL / NLLB-200 transcript translation.
> 01. Context & Objectives
Problem Statement
Heavy video uploads choke network bandwidth and trigger storage limits, while cloud transcription services incur steep API fees. Traditional tools also lack client-side audio extraction, dynamic local/cloud engine switching, and automated multi-language translation.
> 02. Interactive Workflow Preview
Application Lifecycle Simulation
interview_recording_1080p.mp4 (1.4 GB)
File ingested into memory dropzone →Heavy 1.4 GB media files are dropped into the browser for non-blocking local pre-processing.
> 03. System Architecture
Engineering Blueprint
Hybrid speech transcription architecture combining browser-side Web Audio extraction with FastAPI SSE streaming and environment-aware inference (local CTranslate2 GPU execution vs Groq Cloud API in production, plus DeepL/NLLB translation).
Web Audio Extractor
Web Audio API
FastAPI SSE Stream API
FastAPI / SSE
Hybrid Inference Engine
faster-whisper / Groq
Hybrid Translation Engine
DeepL / NLLB-200
Extracts and compresses speech audio from multi-gigabyte videos down to <45MB 16kHz WAV inside browser memory in <1s before upload.
01.Web Audio Extractor
Browser-side Web Audio API (OfflineAudioContext) downsampling multi-gigabyte media to 16kHz mono WAV in <1s before upload.
02.FastAPI SSE Stream API
FastAPI job queue manager streaming line-by-line transcription updates to React via Server-Sent Events.
03.Hybrid Inference Engine
Runs local faster-whisper (CTranslate2) on GPU in local dev, automatically switching to Groq Cloud API (Whisper Large-v3) in production.
> 04. Technology Stack
> 05. Key Highlights
Engineering Specifications
Browser-Side Web Audio Extraction
Extracts and compresses speech audio from 1.4GB+ videos down to <45MB 16kHz WAV directly in browser memory in under 1 second.
Hybrid Engine (Local GPU / Groq Cloud)
Leverages local faster-whisper (CTranslate2) for GPU inference locally, and seamlessly switches to Groq Cloud API for production deployment.
Multi-Engine Transcript Translation
Translates completed transcriptions into multiple languages via DeepL API in production or Meta NLLB-200 locally, preserving subtitle timestamps.