user224, 6 months ago (edited 6 months ago)

I have a QR code in my backpack with rickroll that works offline. It has the “Never gonna give you up” ~2 second cut compressed into 8kbps MP3 and embedded into base64 data tag so you can open it in web browser.
But there’s still a better way. OPUS can do as little as 6kbps and still sound better. Modern browsers should support it just as well.

And theoretically speaking, there’s something called codec2 which goes down to 700bps. Maybe the rickroll would still be recognizable with that. That could do ~22 seconds of audio inside a QR code.
Edit: Forget it. This is how music sounds with 700bps codec 2: auphonic.com/media/…/music-test_700bps.c2.wav
https://auphonic.com/media/audio-examples/codec2/music-test_700bps.c2.wav