PrismShare moves files and live media across a one-way camera-to-screen link. It needs no pairing, network, account or return channel. The open specification is a small family of layers rather than one monolithic format.
PrismShare is the product and project name. PrismShare Code (PS Code) is the colour 2D symbol at its foundation. Aphotic Transfer carries exact files using the Aphotic Fountain for rateless repair. PrismShare Stream carries live media with a bounded redundancy window.
This repository is the authoritative PrismShare Protocol Suite. The reference implementation lives elsewhere; conformance depends on the normative documents and vectors here, not on reproducing its internals.
Naming note. The repository slug is an address, not the standard's name. The canonical repository is
Blue-Heeler-Software/prismshare-spec. Prose and package listings use PrismShare Protocol Suite. See BRANDING.md.
| layer or companion | document | status | purpose |
|---|---|---|---|
| optical symbol | FORMAT.md | normative | Bytes, colours, geometry and headers of a PrismShare Code symbol. |
| decoder guidance | DECODER.md | informative | One measured way to recover a symbol through a camera. |
| optical experiment | BIT-LOADING.md | experimental | Per-channel loading profiles, including the hardware result that falsified the first profile. |
| exact-object payload | APHOTIC.md | normative | Aphotic Transfer pages and the Aphotic Fountain. |
| live payload | STREAM.md | normative | PrismShare Stream frames, redundancy windows and the version 1 audio profile. |
| payment handshake | PSPAY.md | experimental | PS Pay: a signed three-message payment handshake, one static symbol per message. |
The optical format does not know what its payload means. The payload protocols do not know how the symbol is displayed or photographed. This separation is a conformance boundary, not merely an editorial arrangement.
After a PrismShare Code symbol has yielded its payload bytes, the first two bytes select the next layer:
| prefix | payload family | required action |
|---|---|---|
PS (0x50 0x53) |
Aphotic Transfer | Parse as a 13-byte Aphotic page header followed by one chunk. |
PV (0x50 0x56) |
PrismShare Stream v1 | Parse as a 10-byte stream header followed by fixed-size packets. |
PY (0x50 0x59) |
PS Pay (experimental) | Parse as a PS Pay handshake message; readers without PS Pay treat it as a plain document. |
| neither | plain document | Deliver the payload to the application without interpreting it as either protocol. |
One profile pins down a common plain-document payload:
- PSCARD.md - PS Card, a business card: a standard vCard
in one static symbol, never a stream, with an optional brand-colour
extension that only a colour code can carry. Detected by its text beginning
BEGIN:VCARD, not by any transport flag.
PV does not mean “fountain stream.” Exact files and live media deliberately
use different loss disciplines: Aphotic uses rateless coded pages; Stream uses
recent-packet repetition and a playout buffer.
- CONFORMANCE.md defines claimable components and the present proof status.
- VALIDATION.md collects required rejection and ignore rules.
- EXAMPLES.md provides worked wire examples.
- GLOSSARY.md fixes terminology used across the suite.
- VERSIONING.md explains version fields, reserved values and compatibility policy.
- SECURITY.md describes trust boundaries and resource limits.
- vectors/ contains canonical protocol vectors and the scaffold for full symbol conformance vectors.
- CHANGELOG.md separates normative corrections from editorial changes.
This is a working specification, not yet a frozen standard.
- PrismShare Code format version 2 at one bit per channel is proven on real handsets. A paired version 6 H presentation survived a public video platform's transcode at every tested playback quality from 720p upward.
- Higher bit depths and format version 3's per-channel profiles are defined but are not proven through a camera. Profile 1 was implemented and falsified.
- Aphotic Transfer and the Aphotic Fountain are proven on real handsets, including through the same video transcode.
- PrismShare Stream v1 is verified end to end through real cameras. Codec2 1300 inside a version 8 symbol pair carried contiguous speech on the weakest handset tested.
- Canonical Aphotic and Stream protocol vectors now seed the conformance set. Full symbol-image vectors remain a pre-freeze requirement; until they exist, no implementation can demonstrate complete optical interoperability.
“Prism” is heavily used in software and broadcast products. The suite therefore uses PrismShare as its primary compound mark and avoids presenting bare “Prism” as the product name. Aphotic Fountain is the distinctive name of the rateless repair mechanism; “fountain code” remains beside it as the searchable technical description.
This naming policy is product architecture, not legal clearance. Before a commercial launch, obtain professional trade-mark searches in the intended classes and countries and check app-store, package, domain and social handles.
PrismShare is an independent open format. Every plane of a PrismShare Code symbol is a QR Code, and QR Code is a registered trademark of DENSO WAVE INCORPORATED. This project is not endorsed by or affiliated with the trade-mark holder. Implementers are responsible for assessing any intellectual property applicable to QR Code encoding and decoding in their jurisdiction.
PrismShare Code and its Aphotic Transfer and PrismShare Stream payload protocols were created and authored by aXL333 and are published by Blue Heeler Software.
The first public revision incorporates a detailed format review by NomNomski. The review drove the split of the normative format from the reference decoder, corrections to capacity and calibration arithmetic, honest accounting of proven versus defined configurations, and separate documents for file transfer and live streaming.
These specifications are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). You may share and adapt them, including for commercial use, with attribution. See LICENSE.
SPDX-License-Identifier: CC-BY-4.0