Building an offline subtitle extractor with whisper.cpp and Electron

I watch a lot of foreign language content - anime, K-dramas, tech talks - and getting subtitles was always a pain. Upload to a random website, hit the daily limit, try another one, or install Python and figure out whisper's CLI. So over the past few months I've been building a desktop app that handles the whole pipeline locally. What it does You drop a video file in, pick a whisper model size, and it spits out an SRT subtitle file. Optionally you can translate the subtitles using one of several engines. The speech-to-text runs via whisper.cpp so everything stays on your machine. No uploads, no API calls for the transcription part. If you have an NVIDIA GPU it automatically uses CUDA, otherwise it falls back to CPU - this was one of the trickier parts to get right. Tech decisions I went with Electron + Node.js because: Cross-platform (though I'm mainly targeting Windows right now) Easy to bundle whisper.cpp binaries and ffmpeg The UI is just HTML/CSS/JS so iteration is fast For whisper.