iamf-sentinel-pro — L3 rendered QC plugin for iamf-sentinel

The free core (iamf-sentinel) reads the file. This plugin decodes it and measures the truth:

• L3 rendered QC — decode each mix presentation × declared layout through the reference decoders (as subprocess oracles) and measure BS.1770-4 integrated loudness and true peak with an independent, calibrated implementation — catching declared-vs-measured loudness lies that descriptor checks can't see.
• Channel identity on decoded PCM — catches the pure essence-misroute corruption (descriptor-clean, PCM-scrambled) that even L2 cannot see from the bitstream alone.
• Source-referenced ADM fidelity QC (adm-compare, S-33x) — compares an IAMF encode against its BW64/ADM master.
• Platform profile packs (e.g. YouTube ingest) with the loudness-measurement calibration that keeps correct files from being flagged at tight tolerances.

The core discovers this package by import (see PLUGIN_SEAM.md): its presence enables sentinel validate --l3, diff --render, adm-compare, and the profile packs in sentinel_pro/profiles/.

Free software, Apache-2.0.

Code comments throughout cite an internal numbered design docset (doc NN), ADRs, and pre-registered expectation labels — DESIGN-NOTES.md explains the notation and indexes every cited document.

Install & backends

pip install iamf-sentinel-pro            # kernel-backed: no scientific stack required
pip install "iamf-sentinel-pro[numpy]"   # adds the numpy reference backend (quotes: zsh eats bare brackets)

Measurement runs on the compiled sentinel-dsp kernel when the binary is present ($SENTINEL_DSP explicit path, else $PATH; SENTINEL_DSP=off forces the reference path) or on the numpy reference implementation. A present-but-broken kernel is an execution error, never a silent fallback. adm-compare and diff --render always need the [numpy] extra.

Build the kernel:

cmake -S sentinel-dsp -B build -DCMAKE_BUILD_TYPE=Release && cmake --build build -j2

Every change to either measurement implementation is gated by the differential suite (sentinel-dsp/tests/differential.py + tests/test_dsp_backend.py).

Verified platforms. Every push runs the Pro test suite on Linux, macOS, and Windows against Python 3.11 and 3.12 — ci.yml is the claim; the matrix is the evidence. That matrix covers the Python side of Pro; the C++ kernel and its differential against dsp.py are gated separately, on Linux only, by dsp-differential.yml — a green matrix here says nothing about the kernel, and vice versa. Oracle-gated, sample-gated and kernel-gated tests skip in that environment by design, and on Windows so do the tests that depend on POSIX executable semantics (shell stubs, PATH resolution of extensionless files). Nothing is claimed for a platform that does not have a green leg.

L3 and adm-compare additionally need the reference toolchain (decoder_main / iamfdec) and, for adm-compare, EAR (ear-render). The OCI recipes under oci/ package the toolchain reproducibly; oci/layer-scan.py is the release-CI hygiene check.

Related projects

• iamf-sentinel — the free, stdlib-pure core this package plugs into (L1/L2 + CI contract)
• iamf-loom — manifest-driven IAMF packager; its validation gate uses this stack's measurement
• iamf-adm-corpus — synthetic ADM corpus + harness behind the adm-compare method
• iamf-sentinel-mcp — MCP server exposing the validator and packager to agent runtimes

License

Apache-2.0 (see LICENSE / NOTICE). This tree was designed as the commercial half of an open-core split; the project has since adopted a full open-source posture and both sides are Apache-2.0 — the plugin seam remains as architecture, not a license boundary. The measurement DSP (Python and C++), the ADM reader, and all checks are original clean-room works (ITU-R BS.1770-4, ITU-R BS.2088 / EBU Tech 3285, ISO/IEC 14496-12). Reference decoders and EAR are invoked only as subprocess oracles. Commercial support and consulting are available — see the core repo's SUPPORT.md.