One scene. 965 ways to forge it.

965 legal immersive-audio variants. Before you even choose a bitrate.
Independent, clean-room ADM → E-AC-3/JOC encoding, built in Rust.

Explore the variants · Quick start · Validation evidence · Developer guide

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965 structural variants	5 public JOC profiles	2,393 supported cells	0 modeled implementation gaps
Bitrate choices excluded	idx0 through idx4	Including bitrate choices	Applicable, unambiguous, capacity-viable space

The 965 difference

JOCForge can generate 965 legal E-AC-3/JOC immersive-audio variants, excluding bitrate options. Compose profiles, carriage, metadata signaling, block partitions, dependent substreams, and LFE ownership through one standards-derived encoding planner.

These are distinct supported configurations in the project's modeled public ETSI space. Count each supported combination of profile × container × carriage × EMDF signaling × block partition × dependent count × LFE ownership once, leaving bitrate out. At least one modeled bitrate supports each variant; every bitrate does not support every variant.

Profile	Carrier family	Variants without bitrate
idx0	5.X	185
idx1	Flat-7.X	201
idx2	5.X+2	201
idx3	5.X Phase	177
idx4	5.X+2 Phase	201
Total		965

Phase profiles use distinct public signaling with the corresponding carrier family; they do not add a PCM phase transform. The capability matrix defines supported combinations and the capability freeze defines their scope.

Build the stream around the scene

Capability	What JOCForge brings
Scene → objects	Deterministic N-to-15 reduction with signal, spatial, and energy weighting, temporal continuity, and explicit source accounting.
Choose your carriage	Raw ETSI I0 + dependents, I0 skip-field carriage, and an advanced legacy AC-3 core path. Strict and deployed EMDF signaling are explicit choices.
Shape the frames	Genuine source-derived raw partitions: 6, 3+3, 2+2+2, and 1+1+1+1+1+1, preserving 1,536 samples per programme interval.
Own the topology	Multiple dependent substreams up to the profile's semantic ceiling, final-dependent JOC/OAMD ownership, and explicit independent or dependent LFE routing.
Package for CMAF	Advanced fragmented ec-3/dec3 output for validated no-LFE, strict, six-block I0+D0 profiles at 1664 kbps.
Trace the result	Independent OpenJOC inspection/rendering, FFmpeg decode evidence, carrier/source causality, and per-source accounting.

Supported combinations are resolved before ADM I/O. Ambiguous structures, insufficient capacity, and unsupported ownership fail with explicit classifications. The matrix defines which features compose.

Forge your first stream

Install Rust 1.85+ and put FFmpeg on PATH for a source checkout. Generate a synthetic scene and encode it without downloading source media:

cargo run -p jocforge --locked -- fixture --seconds 4 artifacts/demo/scene.bw64
cargo run -p jocforge --locked -- encode artifacts/demo/scene.bw64 artifacts/demo/scene.ec3 --profile idx0

Try Flat-7.X by choosing --profile idx1, or explore all five profiles and advanced carriage in the developer guide.

Input support covers 48 kHz integer PCM BW64/RF64/RIFF with static ADM, including supported Objects and positioned DirectSpeakers. The parser requires full-track timing, a single position block, and unambiguous CHNA bindings. Full ADM and complete non-LFE bed semantics are outside the current scope.

Output commands create missing parent directories and replace existing targets. Failed encodes remove the target and generated sidecars, so choose output paths deliberately.

Official Windows release bundles include separately licensed, pinned FFmpeg and ffprobe executables. See third-party notices for license and provenance details.

Evidence you can inspect

The version-scoped interoperability census tests 20 legal probes selected from the capability model:

Reference	Observed result
OpenJOC 0.16.0	20/20 inspection/render-or-container-decode gates passed: 19 raw renders and one CMAF decode.
FFmpeg 8.1	14 full decodes; 6 partial results from additional-substream coverage.
MediaInfo 21.03	1 JOC recognition; 19 E-AC-3-only false negatives.

The 965 count describes supported compositions, not 965 individually rendered census probes or universal device compatibility. Decoder and detector observations do not determine standards legality. Read the probe results and limitations.

Reproduce the 965 count

Generate the authoritative matrix, then collapse supported rows across bitrate:

.\scripts\generate-joc-capability-matrix.ps1
$supported = Import-Csv artifacts/composition-capability-matrix.csv |
  Where-Object verdict -eq 'SUPPORTED_PASS'
($supported | Group-Object profile,container,carriage,emdf_profile,partition,dependent_count,lfe_ownership).Count
# 965

The complete model contains 140,400 rows, including 2,393 supported cells and zero SPEC_LEGAL_NOT_IMPLEMENTED cells. This is a bounded public-spec implementation claim.

Run the controlled proof and workspace checks

The controlled proof requires the separately provisioned pinned OpenJOC validator, plus Rust and FFmpeg.

.\scripts\run-mvp.ps1
cargo fmt --all -- --check
cargo check --workspace --locked
cargo clippy --workspace --all-targets --locked -- -D warnings
cargo test --workspace --locked

For local ADM, generalized closure, and advanced encoding examples, use the development and validation guide.

Where the project stands

0.1.0-dev is an encoder proof focused on structural coverage and reproducible validation. JOCForge owns its JOC/OAMD/EMDF writer and source-derived dependent carriage; FFmpeg supplies an external audio-core encoder, and OpenJOC serves as an independent validation reference.

The current algorithm uses a full matrix, one coarse parameter band, and bounded source-derived carrier fields. Perceptual encoder parity, production mastering quality, lossless ADM recovery, and Dolby certification are not claimed. Frequency-local optimization and complete non-LFE bed mapping remain research work.

Go deeper

Document	Explore
Capability matrix	Supported compositions and rejection boundaries
Capability freeze	Scope, counts, and zero-gap invariant
Developer guide	Build, encode, reproduce, and audit
Clean encoder design	Reduction and source-derived encoding decisions
Interoperability census	Version-pinned external evidence
Provenance	Clean-room sources and implementation boundaries

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Forge the topology. Keep the evidence.

JOCForge source and workspace crates are Apache-2.0. FFmpeg retains its separate license. The source license does not grant trademark rights or resolve third-party patent questions.