GallaTarun/kyc-bypass ? reverse-engineered prompt

Build me a simple Python desktop app with a small GUI that lets me choose a video file or webcam feed and send it to a virtual camera, so I can test camera based apps without using my real webcam.

I want a clean window where I can start and stop the feed, pick the source, and see a basic preview before it goes out. If you need to look up current docs online for the virtual camera part, go ahead. Keep it lightweight, easy to run, and make sure the setup instructions are simple enough for someone who is not very technical.