Engineer shrinks MP3 song 1,000 times, prints it as 8 QR codes on a single sheet of paper

A hobbyist engineer known as Makestreme has successfully compressed a three-minute MP3 song into a set of QR codes that fit on a single sheet of paper. The project was reported by Tom's Hardware.

To achieve this, Makestreme used Meta's neural audio codec EnCodec, which reduced the original 2.9 MB MP3 file to approximately 21 KB of encoded data — a compression ratio of nearly 1,000:1. The resulting data was split into eight QR codes and printed on both sides of a sheet, with four codes per side. Each QR code contains a 1-byte identifier and a portion of the token stream. To maximize data density, the lowest error correction level was used, meaning any damage to a single code makes the song unplayable.

In addition to the paper printout, Makestreme tested transmitting the same file between two ESP32 microcontrollers using LoRa radio modules at 866 MHz. Data was sent in 160-byte packets with acknowledgment and retransmission on packet loss. The transmitter code includes a 40-second pause after each acknowledged packet. For a 21 KB file, roughly 134 packets are needed, resulting in a total transmission time of about 90 minutes per song. This slow pace was chosen to comply with duty cycle regulations.

EnCodec works by converting a sound wave into discrete tokens, which are then decoded back into audio. At a bitrate of 3 kbps, the reconstructed track retains acceptable quality, while at 1.5 kbps the sound degrades significantly.