0022 — the build & distribution matrix¶

Status: POLICY AGREED; WASM + NATIVE PROFILE MACHINERY IMPLEMENTED (linux/amd64) (refined 2026-07-02 — the lean/intermediate/full profile model, the runtime×profile mapping, and the native platform set are RESOLVED with the user; the concrete codec-set-per-profile in §6 is the proposed starting policy. This spec governs the codec-bundling decision every other spec defers to. Built 2026-07-03 (Phase 2): the WASM-side PROFILE build-arg — ffmpeg-wasi build/ now takes PROFILE=lean (default; the legacy ffmpeg-wasi-<variant>.wasm artifact, unchanged) or PROFILE=intermediate (a new ffmpeg-wasi-intermediate-<variant>.wasm that starts byte-identical to lean, with an empty INTERMEDIATE_ENABLE hook the 0015/0016/0017 batches fill additively). Verified: both profiles build, intermediate runs the full integration suite (≡ lean capability), a bogus profile is rejected. NATIVE PROFILES IMPLEMENTED (linux/amd64, 2026-07-05, with 0028): the native driver now builds all three profiles — lean, intermediate (≡ wasm intermediate, the load-bearing parity), and full (native-only: intermediate + x265/HEVC gpl + SVT-AV1 both, spec 0023). Published + signed as ffmpeg-wasi-driver-linux-amd64-[<profile>-]<variant>; afmpeg selects via WithReleaseProfile (wasm: lean/intermediate through WithModuleRelease; native: all three through native.NewFromRelease, full rejected on the wasm path). Downstream/uncommitted: the remaining native platforms (linux/arm64, darwin/arm64 — the real cross-build cost), HW-accel members of full (device-gated), and the CI size-budget gate.) Date: 2026-06-30 (refined 2026-07-02) Parent: 0012, 0007 Governs the bucketing for: 0015 0016 0017 0018 0019 0023; the native runtime is 0028. Owns: R-AF-3 (the build-variant / size-matrix portion)

1. Why¶

As the parity specs add codecs/formats/filters and 0028 adds a native runtime, "what goes in which distributable?" needs one governing policy rather than each spec guessing. This is it: the axes, the profiles, the artifact matrix, and the release/signing/pinning implications. The codec specs (0015–0019, 0023) each say what a codec is; this spec says which artifact it ships in.

2. The axes¶

3. The profiles — capability classes¶

• Lean — web-delivery essentials: the codecs/containers/filters that cover the great majority of real jobs at the smallest size. Roughly what ffmpeg-wasi ships today. WASM only.
• Intermediate — lean + every practical software codec (no hardware, no heavy thread-hungry encoders): the native-decoder batch, the LGPL encoder libs, the full filter set, all software containers, subtitles, AV1-decode. Both runtimes, and byte-for-byte the same codec set in each (D-0022-B — clean partitions; intermediate never flexes or muddies between WASM and Native).
• Full — intermediate + the heavy hitters: heavy software encoders (x265/HEVC, software AV1 encode) and hardware-accelerated codecs (NVENC/VAAPI/VideoToolbox/QSV). Threads + SIMD + hardware make these viable, so Native only.

The load-bearing property: intermediate is identical in WASM and Native. A consumer develops against WASM-intermediate (sandboxed, portable, slower) and drops to Native-intermediate (identical capabilities, fast, unsandboxed) with zero code or codec-support change — only the performance/security posture shifts.

4. Runtime × profile mapping¶

• WASM → { lean, intermediate }. No WASM-full: HW-accel and the heavy encoders need native.
• Native → { intermediate, full }. No Native-lean: native's whole point is capability, so intermediate is its floor.

5. The artifact matrix¶

Per release:

= 16 signed artifacts per release (Windows, when un-deferred, adds intermediate+full × lgpl+gpl = 4 → 20). We do not shy from this number — §7 shows it costs one signature, plus a build matrix.

6. Codec-set-per-profile — the proposed policy (what the other specs defer to)¶

Additive: each profile is the previous plus its column. Codec specs are cited for the source of each set.

Licence placement: openh264 → all (LGPL); libx264 → any gpl variant (incl. lean-gpl); x265 → full-gpl only (GPL + heavy); HW-accel encoders → both licences (the hardware encodes, the wrappers are LGPL-compatible); the LGPL encoder quartet (Opus/MP3/VP8-9/WebP) → both.

7. Release, signing & pinning¶

• Signing scales for free. One checksums.txt + one OpenPGP signature per release covers all 16 artifacts (the manifest just lists more files) — the 0010/0011 model is unchanged; WKD/provenance don't grow. provenance.json enumerates every (runtime, profile, licence, platform).
• Consumer selection. afmpeg's variant generalises to (profile, licence); WithModuleRelease picks the WASM artifact, WithNativeRelease adds the platform auto-detected from runtime.GOOS/GOARCH. A clear error when a requested (profile, platform) isn't published.
• The real cost is the native build matrix, not the count. Cross-compiling libav* + the driver for darwin/arm64 and linux/arm64 from the CI host needs per-target toolchains/sysroots (goreleaser-style runners or cross-SDKs). 16 CI build jobs. This — not signing — is the genuine new engineering, and it lands with 0028's native tier, not before.

8. Decisions¶

• D-0022-A — three profiles (lean/intermediate/full) defined by capability class, not size.
• D-0022-B — intermediate is identical across WASM and Native. RESOLVED (2026-07-02): clean partitions; no flexing or muddied middle.
• D-0022-C — heavy software encode (x265, software AV1) lands in FULL, not intermediate. RESOLVED: keeps intermediate clean + practical single-threaded.
• D-0022-D — mapping: WASM {lean, intermediate}; Native {intermediate, full}.
• D-0022-E — lean ships BOTH LGPL and GPL. RESOLVED: x264 offers quality gains; let consumers choose.
• D-0022-F — native platforms: linux/{amd64,arm64} + darwin/arm64. RESOLVED; Windows deferred, no date.
• D-0022-G — one signature per release covers every artifact (no per-artifact signing).
• Open: the exact lean vs intermediate line for a few borderline decoders; whether WASM-full is ever warranted (currently no); the provenance/naming scheme for 16+ assets.

9. Requirements¶

• R-AF-3 (size/variant portion) — releases publish the profile × licence × runtime × platform matrix (§5); each artifact's codec set follows the §6 policy; intermediate is identical across runtimes; all artifacts are covered by a single per-release signature; afmpeg selects by (profile, licence, platform). A per-artifact size budget + a CI size-assertion gate.

10. Sequencing & dependencies¶

This spec gates the bucket placement the codec specs (0016/0017/0018/0019/0023) defer to — so it should be settled before those build. The WASM profiles (lean/intermediate) can ship first (no new runtime); the Native profiles (intermediate/full) + the platform matrix depend on 0028 and its build toolchain. Supersedes the current lgpl/gpl-only variant model (0007 §5, ffmpeg-wasi variants.md), which becomes the WASM-lean row of this matrix.

11. Definition of done¶

The axes, the three capability-class profiles, the runtime×profile×licence×platform matrix (16 artifacts), the codec-set-per-profile policy, and the release/signing/pinning implications are recorded and agreed. The codec specs cite §6 for placement; 0028 cites §5/§7 for the native matrix; the size-budget gate is specified. Implementation (the build matrix, the native toolchains, the afmpeg selection API) is downstream and uncommitted here.