OTape

oTAPE is an open file format designed to represent a complete digital cassette rather than a playlist. Each file contains two fixed-length sides, with each side stored as one continuous recording; track markers can identify songs without removing pauses, spoken introductions, or other gaps. Playback follows tape-like rules: listeners wind rather than jump, flip the tape to reach the other side, and keep their listening position separately without altering the file. The format preserves cassette details such as record-protect tabs, shell appearance, labels, J-cards, booklets, and liner notes. Technically, an .otape is a ZIP archive with a JSON manifest and AAC audio, plus optional artwork and documents. Its specification defines physical dimensions, tape lengths, sample-accurate timing, and compatibility rules.

The format also supports optional sound processing that imitates different cassette machines, including speed variation, hiss, warmth, and wear; these effects are applied during playback, leaving the recording unchanged. The accompanying browser deck plays files locally, while Studio apps let users record music files, radio, or audio input onto a tape in real time and save the result. The Mac and web studios provide transport controls, tape design tools, validation, and cassette-length options. Developers can implement the format without royalties or permission, using a short set of rules for reading files, playing recorded sections, winding, rendering artwork, and remembering playback position. A validator and example tapes support testing.