Sunday, March 14, 2021

QRTape | Audio Playback from Paper Tape with Computer Vision

Here is a project that I have been tossing around in my head for at least a year or two now. Given advances in audio compression algorithms and computer vision: could reasonably high-quality audio be stored on a paper tape?

This is a fascinating concept to me. When considering the complete history of storage media from early cylindrical engraved records through to magnetic tape it is evident that achieving high quality and reliable data storage is both challenging and expensive. When specifically considering magnetic tape, the challenges surrounding complex mechanical tape transports and sensitive electronics highlight some of the difficulties that engineers have faced in the past.

In this blog I demonstrate a system that exploits modern computer vision and audio compression to replace the complex mechanical tape transports of the past. In fact, my tape transport is made entirely from paper and cardboard (excluding some electronics, of course). I have decided to call this system QRTape.

QRTape Player
Under the QRTape system, data is encoded by a series of QR codes that are printed on a continuous strip of paper. This strip of paper is fed from one spool through a crude tape transport, past a webcam and onto a take-up spool. The paper is advanced by a small stepper motor driven by a cheap Arduino. The rest is pure software magic.