/ Lossless by Default

Perfect reconstruction, always.

Every codec defaults to Q1 — lossless, with exact round-trip reconstruction guaranteed for all signal types. Lossy modes are opt-in, using a quality ladder derived from Lucas numbers rather than arbitrary tuning parameters.

/ Deterministic Output

Same input, same bytes, everywhere.

All four codecs are blockchain-deterministic: given identical input and quality setting, the encoded byte stream is bit-for-bit identical across every supported architecture and platform. Reproducibility is a hard design requirement, not a best-effort property.

/ One Foundation

Shared core across all domains.

The core lossless library — φrANS entropy coding, Triveni lifting, and block classification — is shared across all three signal codecs. Audio, image, and video each add a domain-specific prediction stage on top of a common algebraic substrate.

The Family

One core. Three signal domains.

The family is organized as a dependency stack. The core library provides the shared entropy coder, lifting transform, and block classification that every signal codec relies on. Each domain codec adds its own prediction stage and block geometry on top of that shared foundation.

/ Group 01

Core Library

The shared foundation on which all three signal codecs are built. Provides φrANS entropy coding, the Triveni 2D lifting transform, per-block mode classification, and the RPC frame codec used by phi-rpc-cpp. All signal-domain codecs depend on this library.

Quality Tiers

The Lucas quality ladder.

All three signal codecs share an identical quality ladder. Each tier's quantization step is a Lucas number — the same sequence that governs the φCrypt security tiers. Q1 is always lossless. Tiers increase by the same ratio that governs the rest of the framework, giving predictable quality gradations without arbitrary tuning.

  • / Q1

    Lossless — quantization step 1

    The default quality. Perfect reconstruction guaranteed. Identical output across every architecture. Used for archival, blockchain payloads, and any context where round-trip exactness is required.

    Step: L(0) = 1 · All codecs · Default
  • / Q2 – Q3

    Near-lossless — steps 3 and 4

    Minimal perceptible loss on most material. Suitable for preview generation, streaming at constrained bandwidth, and applications where slight deviation from lossless is acceptable.

    Steps: L(2) = 3, L(3) = 4 · All codecs
  • / Q4 – Q5

    Lossy — steps 7 and 11

    Visible quality reduction; high compression gains. Audio speech targets ≤0.45× original size; image targets ≤0.28×; video targets proportional to scene complexity. The primary production lossy tiers.

    Steps: L(4) = 7, L(5) = 11 · All codecs
  • / Q6 – Q7

    Aggressive — steps 18 and 29

    Maximum compression at significant quality cost. Audio speech targets ≤0.30×; image ≤0.14×. Reserved for bandwidth-critical or storage-constrained contexts where quality is secondary.

    Steps: L(6) = 18, L(7) = 29 · All codecs
Licensing & Access

Using φCompress?

All components are published under AGPLv3. For commercial deployment in closed-source products, a commercial patent license is available.

Back to Projects Commercial License