Projects 01

In progressv0.1.0a2 · Analysis shipped · Reference mastering shipped

WPAudio Engine

A professional, explainable audio analysis and intelligent mastering engine, written in modern Python.

What WPAudio Engine is

It is not an AI mastering black box.

Every decision WPAudio Engine makes answers three questions — what, why, and how. Not as a comment in the source, and not as a paragraph in a manual. Each answer carries the metric IDs it used, the thresholds it compared against, the confidence it had, and what it chose to protect at the cost of something else.

Mastering tools that work well tend to be either a cloud service you upload to and hope, or a chain of processors that will not tell you what they did. WPAudio Engine is an argument that an engine can make good decisions and account for them.

01

The pipeline

Five stages, with strict boundaries between them. Three are built, one is partly built, and one is an empty package with a name.

  1. 01Built

    Audio

    Immutable buffer, loader

  2. 02Built

    Analysis Engine

    Five analyzers, 39 metrics

  3. 03Not yet built

    Decision Engine

    Milestone M2 — empty package

  4. 04Partially built

    DSP Engine

    Reference mastering only

  5. 05Built

    Report Engine

    HTML, JSON, CSV

One line through five stages. A built stage is a filled node joined by a solid segment; the partly built stage is a ring joined by a long dash; the planned stage is a quiet ring joined by a short dash. Each stage says its state in words above its name.

  • Analysis never modifies audio.
  • Decisions never analyze audio.
  • DSP never makes decisions.

Those are three of twelve rules the project holds itself to. The one that matters most for explainability is blunter: the “why” is not a comment — it is a test. A rule that cannot be asserted against a table of inputs and expected decisions does not ship.

02

Where it is today

Working
  • Five analyzers — level, integrity, spectrum, loudness, stereo
  • True peak measurement with 4× oversampling, per ITU-R BS.1770-4 practice
  • Album-level analysis: cross-track statistics and outlier detection
  • Mastering verification — original against master, with delivery checks
  • Engineering reference masters from a deterministic, documented recipe
  • HTML, JSON and CSV engineering reports
  • A command line for a track, an album, a comparison or a master
Not yet built
  • The Decision Engine — mastering intent, with evidence and confidence
  • A general DSP graph — today there are primitives, not a node system
  • Intelligent mastering end to end: the targets are still an engineer’s
  • Any graphical interface or plugin format
Tests passing
395
Branch coverage
95.98%
Runtime dependencies
3
Decision records
8

Ruff and strict MyPy clean. Python 3.12+, on numpy, soundfile and pyloudnorm — three runtime dependencies, deliberately.

A note on names: WPAudio Engine is the product. aurora is the code name and the Python namespace it was born in — the package is aurora-dsp and the command is aurora. WPAudio Engine is what it is called; import aurora is what the code says.

03

The interface

Not a mockup — the engine running locally, mid-session, on a track from Wings & Prayers. It analysed the file, mastered it to a stated target, then re-opened the written file from disk and checked its own work with a second, independent meter.

The WPAudio Engine interface after mastering a track: an independent verification
               panel reading VERIFIED, with integrated loudness and true peak checks both passing
               against their stated targets, beside the mastered file's measured loudness, true
               peak, loudness range, sample rate, bit depth and channel count.
Every number on screen is measured, not simulated — the verification pass included, from a meter that shares no code with the mastering path. Built for the Studio's own mastering workflow. Not a hosted product, and nothing here is asking for a signup.

WPAudio Engine identity

The WPAudio Engine product splash: the WP monogram over a waveform, ringed by
             illustrative analyser panels — spectrum, loudness, true peak, stereo image, dynamics
             and integrity — above the line Measure. Understand. Decide. Master.
The engine's identity graphic. The panels illustrate the measurement families the Analysis Engine covers; the readings shown in them are artwork, not output from a run. Real numbers from this engine are in the mastering case study.

04

Proved on a real record

Album-level analysis exists because another Studio project needed it. The twelve-track Wings & Prayers album was WPAudio Engine’s first real production workload — thirty-three minutes of finished masters, analysed end to end in seventy-nine seconds. Those reference masters have since shipped: the album was released on streaming platforms on 11 August 2026, byte for byte from the files this engine verified.

Running a real record through it surfaced things a synthetic test signal never would. The clearest: silence was reporting an integrated loudness of 0.0 LUFS — maximal loudness, the worst possible sentinel a loudness metric could pick. It now reports negative infinity, and the JSON exporter serialises non-finite values as null rather than emitting invalid JSON.

One project’s engine, mastering another project’s music. That is the whole studio thesis inside a single working directory.

The full story — every pre-master measured, every reference master verified, and the actual audio to A/B for yourself — is now a case study of its own.

Case studyMastering Wings & Prayers — measure, decide, verify, listenRead it, then hear it

A month later the same engine mastered the same songs again — the Second Flight record — to a different brief: one platform-reference level for every track, and every figure cross-checked by a meter from outside the project before it was published.

Case studyMastering Second Flight — one target, every number measured twiceRead the measurements

05

Coming here

Reserved, with URLs held. Each stays empty until there is something real behind it.

  1. 01

    Architecture

    Reserved

    The signal chain and module contracts, drawn out.

  2. 02

    Decision records

    Reserved

    Eight exist in the repository. They belong here.

  3. 03

    Benchmarks

    Reserved

    A harness exists; no results are published yet.

  4. 04

    Roadmap

    Reserved

    Read from the repository, not maintained twice.

  5. 05

    Documentation

    Reserved

    Getting started, then reference, as the API settles.

  6. 06

    WPAudio Cloud

    Reserved

    A later chapter. Not a product, and not a waitlist.

06

Engineering journal

WPAudio Engine

Publish only what you can measure

The mastering case study forced a decision about evidence — quote the private engineering reports, or measure the published files. Choosing the second changed what the page could honestly say, and produced ADR 0007.

  • DSP
  • Software Architecture
Read