QRTape | Audio Playback from Paper Tape with Computer Vision
Hacker News
February 23, 2026
AI-Generated Deep Dive Summary
A new project called QRTape is revolutionizing audio storage by using paper tape and computer vision to create a low-cost, eco-friendly alternative to traditional magnetic tape systems. By leveraging modern audio compression algorithms and QR code technology, the system encodes high-quality audio onto a continuous strip of paper, which is then read by a webcam and decoded through software. This innovative approach simplifies what has historically been a complex mechanical process, replacing expensive and intricate tape transports with basic materials like cardboard, tape, and a small stepper motor controlled by an Arduino.
The QRTape system uses QR codes to store audio data, with each code containing sequence numbers and CRC16 error checking for accuracy. The paper tape is fed through a simple transport mechanism, where it passes under a webcam that reads the QR codes at a rate of 1-2 per second. This setup allows for continuous playback without requiring any mechanical precision beyond basic tension control. A light source flattens the tape as it moves, ensuring consistent scanning, while a stepper motor on the take-up side pulls the tape forward.
The project’s hardware is intentionally minimalist, using readily available materials like paper towel cores and cardboard spools to keep costs low. While there are opportunities for improvement—such as adding a centering mechanism or bidirectional motor control—the current system already demonstrates impressive functionality with minimal resources. The software side of the project employs off-the-shelf tools like ZBar for QR code decoding and Opus for efficient audio compression, which enables high-quality playback at just 16kbps.
This breakthrough in audio storage technology not only challenges traditional methods but also opens up new possibilities for creative applications. For instance, QRTape could be used as an educational tool to demonstrate how data is stored and retrieved, or as a low-cost solution for archiving audio content in settings where resources are limited. By repurposing everyday materials and leveraging cutting-edge computer vision and compression techniques, QRTape offers a fresh perspective on audio storage that is both affordable and environmentally conscious.
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Originally published on Hacker News on 2/23/2026