* feat(producer): enable webm in distributed mode via concat-copy PR 8.2 of the WebM distributed-rendering plan (v1.5 backlog #1; see DISTRIBUTED-RENDERING-PLAN.md §7.2). Wires libvpx-vp9 webm through the distributed pipeline now that PR 8.1 proved concat-copy works. Architectural decision: Path A (concat-copy) — based on PR 8.1's smoke test result (9/9 tests pass for both yuv420p and yuva420p VP9 streams). The simpler architecture wins; no re-encode in assemble, no encode- parallelism loss. Changes: - plan.ts: - DistributedRenderConfig.format and PlanResult.format now include "webm" — type-level acceptance matches the runtime gate. - rejectUnsupportedDistributedFormat() no longer trips on webm. HDR mp4 remains the only refused configuration. - resolveEncoderTriple() returns libvpx-vp9-software + yuva420p + preset="good" for format="webm". yuva420p preserves alpha — the format's main reason for existing for web delivery. - codec= remains rejected for non-mp4 formats (mov is always ProRes 4444; webm is always libvpx-vp9). The error message lists all four distributed-supported formats. - FormatNotSupportedInDistributedError docstring updated to reflect the new reality (only HDR is unsupported). - freezePlan.ts: LockedRenderConfig.encoder gains "libvpx-vp9-software". Mirrors libx265-software / prores-software / png-sequence in shape; the chunk worker reads this discriminant to decide encode args. - renderChunk.ts: drops the now-incorrect cast that excluded webm from buildSyntheticRenderJob's format input; tightens the preset-format cast to include webm. - assemble.ts: docstring + comment updates. The mp4/mov concat-copy path is format-agnostic — webm uses the exact same code (applyFaststart is a no-op for webm via the existing chunkEncoder.ts gate; muxVideoWithAudio already routes webm to libopus audio). - planFormatBanlist.test.ts: webm-rejection tests removed; replaced with "accepts webm" tests + a HDR+webm combo test that verifies HDR is the trip regardless of format. - plan.test.ts: new describe block pins the webm wiring contract: format="webm" produces an encoder=libvpx-vp9-software / pixelFormat=yuva420p planDir with closedGop=true and gopSize=chunkSize. - webm-concat-copy.test.ts (smoke): extended with a yuva420p variant that proves the alpha pixel format the distributed pipeline actually emits also round-trips through concat-copy. 9/9 tests pass locally. §8 format support matrix in DISTRIBUTED-RENDERING-PLAN.md is intentionally left unchanged at this PR — it flips to ✓ in PR 8.4 once the end-to-end fixture (PR 8.3) is green. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * fix(producer): include webm in plan-time needsAlpha + strengthen alpha smoke PR review feedback from Miguel and Vai on #951 caught a real bug: `plan.ts`'s `needsAlpha` disjunction excluded `"webm"`, so the plan stage froze `forceScreenshot: false` into the `LockedRenderConfig` even though distributed webm uses `yuva420p`. Every chunk worker captured opaque RGB via BeginFrame (which doesn't preserve alpha on Linux headless-shell), and libvpx-vp9 encoded uniformly-opaque alpha that the encoder then dropped — producing un-keyable webm. Two changes: 1. **plan.ts**: include `"webm"` in `needsAlpha`. Matches the in-process renderer's logic at `renderOrchestrator.ts:1469` (`const needsAlpha = isWebm || isMov || isPngSequence`); the two sites must stay in sync since the distributed pipeline's PSNR regression compares against the in-process baseline. 2. **Smoke test (yuva420p describe)**: source frames now use a real alpha gradient (`geq=a='X*255/W'` on top of `testsrc2`) instead of `testsrc2 + format=rgba` which was uniformly opaque. The decode- pix_fmt assertion is dropped (ffprobe reports `yuv420p` for VP9-with-alpha because the alpha lives in a Matroska `BlockAdditional` sidecar) and replaced with two stronger checks: - `TAG:ALPHA_MODE=1` is present on the stream — proves the encoder was actually configured for alpha - alpha plane variance after `-c:v libvpx-vp9 -i ... -pix_fmt rgba -vf extractplanes=a,signalstats` — proves the alpha sub-stream round-trips through concat-copy with spatially-varying content, not uniform/dropped alpha - decode-test gate is now exit-code-only (was `exitCode || stderr` which would flake on chatty ffmpeg `-v error` builds emitting non-fatal DTS/container notes) These checks would have caught the `needsAlpha` bug before review. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * fix(aws-lambda): widen narrow format types to include webm CI on PR #951 was failing at typecheck/build because the producer's `DistributedRenderConfig.format` widened to include webm in this PR but the aws-lambda package's narrow `"mp4" | "mov" | "png-sequence"` type literals in `events.ts`, `handler.ts`, and `validateConfig.ts` hadn't kept up. `renderToLambda.ts:87` passed `config.format` (now including webm) into a parameter typed against the narrow union, producing TS2345. This widening originally landed in PR #952 (test fixture PR) but needs to be atomic with the producer's widening here to keep each PR independently typecheck-clean. Also refactor `formatExtension` from a switch dispatch to a `Record<DistributedFormat, string>` lookup. Adding the webm case tipped the switch's CRAP to the 30.0 fallow threshold; the lookup table drops cyclomatic from 5 to 1 with the same compile-time exhaustiveness guarantee (TS errors on missing entries when `DistributedFormat` adds a new format). The runtime `_exhaustive: never` throw was only protecting against a string slipping past TS; `validateConfig.ts`'s `ALLOWED_FORMATS` already gates untrusted input at the SDK boundary. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * test(producer): add webm-vp9 distributed regression fixture PR 8.3 of the WebM distributed-rendering plan (v1.5 backlog #1; see DISTRIBUTED-RENDERING-PLAN.md §7.2). End-to-end regression coverage for the webm distributed path PRs 8.1 and 8.2 wired up. Adds packages/producer/tests/distributed/webm-vp9/ matching the mp4-h264-sdr fixture pattern: a 2-second composition (60 frames @ 30fps) with text, a crossfade across the frame-30 chunk seam, and a continuous icon rotation — exercises chunk-boundary continuity for both display contents and VP9 closed-GOP alpha encoding. `chunkSize: 15` produces 4 chunks so 3 seams are tested, and the crossfade straddles the middle seam to surface alpha-plane discontinuities introduced by alt-ref drift. Baseline regenerated inside Dockerfile.test via `bun run --cwd packages/producer docker:test:update webm-vp9`. Runs in: - in-process mode: byte-identical match against baseline ✓ - distributed-simulated mode: PSNR 56.88-63.49 dB across 100 checkpoints, well above the 30 dB threshold ✓ Wiring updates required to let webm flow through the harness: - regression-harness-distributed.ts: - checkDistributedSupport() no longer rejects webm. HDR mp4 + NTSC fps + non-{24,30,60} fps remain rejected. - RunDistributedSimulatedInput.format widened to include webm. - Docstring + comments updated. - regression-harness-distributed.test.ts: webm-rejection test replaced with "accepts format=webm" test. - regression-harness.ts: the now-incorrect format cast at the distributed-input call site is dropped; comment about why webm was excluded is replaced with "webm is now distributed-supported". - regression-harness-lambda-local-types.ts: RunLambdaLocalInput.format widened to include webm so lambda-local mode can also exercise webm fixtures end-to-end. - aws-lambda webm support (Path A through the Lambda handler): - formatExtension.ts: DistributedFormat gains "webm" → ".webm" case. - events.ts: RenderChunkEvent / AssembleEvent / PlanLambdaResult Format widened to include webm. - sdk/validateConfig.ts: ALLOWED_FORMATS gains "webm". - handler.ts: downloadChunkObjects format param widened. The Lambda handler delegates to the producer's assemble() primitive which PR 8.2 already taught to handle webm (concat-copy + applyFaststart no-op + muxVideoWithAudio with libopus); no Lambda-side rendering changes are needed beyond the type/validation surfaces above. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * docs(aws-lambda): drop stale webm rejection from validateConfig docblock PR #952 review nit (Miguel): the validateConfig.ts file-header comment still claimed the SDK rejects webm, but the runtime check no longer does (ALLOWED_FORMATS now includes 'webm'). Update the docblock to reflect that only force-hdr remains an SDK-side rejection. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * ci(regression): add webm-vp9 to shard-3 + refactor formatExtension Three follow-ups bundled together (Vai's review feedback on PR #952 plus the fallow audit finding that surfaced when the webm case was added): 1. **Wire webm-vp9 into CI regression.** The fixture was added in this PR but never appeared in any `.github/workflows/regression.yml` shard's args allowlist, so the regression harness's positional-args gate skipped it in CI. Append `webm-vp9` to shard-3 (which already carries `mp4-h264-sdr` + `webm-transparency`) so the fixture runs. 2. **Fix stale "four hard gates" prose in checkDistributedSupport docstring.** Earlier in the stack I removed the webm bullet but didn't update the count. Two gates remain (fps + hdr). 3. **Refactor `formatExtension` from switch to lookup table.** Adding the webm case made the switch dispatch's CRAP score hit 30.0 (cyclomatic = 5, plus the function's small body). Replaced with a `Record<DistributedFormat, string>` lookup, which: - drops cyclomatic from 5 → 1, - keeps exhaustiveness enforcement at compile time (TS errors if a new format gets added to `DistributedFormat` without a matching key in the Record literal), - drops the runtime `_exhaustive: never` throw, which was only guarding against an arbitrary string slipping past TS — a caller-side concern, not this function's job. The function now reads as a table lookup, which matches what it actually does, and the fallow audit now reports zero new complexity findings (down from 1). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Producer regression test fixtures
Each subdirectory under this folder is a regression fixture for the
HTML-to-video pipeline. The harness at
packages/producer/src/regression-harness.ts walks every subdirectory,
runs the composition, and PSNR-compares the rendered output against a
checked-in golden baseline.
Fixture layout
<fixture-name>/
├── meta.json # name, tags, PSNR threshold, renderConfig
├── src/
│ ├── index.html # composition entry point
│ └── assets/... # any locally-referenced media
└── output/
├── compiled.html # golden compiled HTML (validated as a snapshot)
└── output.mp4 # golden rendered video
meta.json is validated by validateMetadata in
src/regression-harness.ts. The required fields are:
name(string),description(string),tags(string[])minPsnr(number, dB)maxFrameFailures(integer)minAudioCorrelation(0..1),maxAudioLagWindows(integer ≥1)renderConfig.fps(integer like30or a rational string like"30000/1001")
Optional renderConfig fields:
format—"mp4"(default) or"webm"workers— integer ≥ 1hdr— boolean (defaultfalse)variables— JSON object of render-time variable overrideschunkSize— integer ≥ 1 (used by--mode=distributed-simulated)maxParallelChunks— integer ≥ 1 (used by--mode=distributed-simulated)
Generating / updating a baseline
Always inside Docker. Host Chrome / FFmpeg versions drift across distros, so a baseline captured on the host won't match the bytes CI renders.
# From the repo root.
docker build -t hyperframes-producer:test -f Dockerfile.test .
# Generate a baseline (single fixture):
bun run --cwd packages/producer docker:test:update <fixture-name>
# Generate all baselines (rarely needed):
bun run --cwd packages/producer docker:test:update
The --update flag writes output/compiled.html and output/output.mp4
from the current render. Without --update, the harness compares against
those baselines.
Running the harness locally
# Run every fixture (parallel, in-process mode — the default).
bun run --cwd packages/producer docker:test
# Run a single fixture:
bun run --cwd packages/producer docker:test font-variant-numeric
# Run sequentially (lower memory):
bun run --cwd packages/producer docker:test -- --sequential
Harness modes
--mode=<value> chooses which render path the harness exercises:
| Mode | What it calls | Use for |
|---|---|---|
in-process (default) |
executeRenderJob |
Day-to-day baselines. This is the same path the hyperframes render CLI takes, and it is what produced every existing output/output.mp4. |
distributed-simulated |
plan() → renderChunk() × N → assemble() from @hyperframes/producer/distributed |
Validates the distributed pipeline against the in-process baseline. No Temporal or Lambda involvement — the controller and chunk worker are both this process. |
--mode=distributed-simulated
bun run --cwd packages/producer docker:test -- --mode=distributed-simulated
bun run --cwd packages/producer docker:test font-variant-numeric -- --mode=distributed-simulated
The distributed pipeline cannot run every fixture. Fixtures that fail any of these gates are skipped with a clear log line (and counted as passing in the summary):
fps.den !== 1— distributed mode is integer-fps only (no NTSC).fps.num ∉ {24, 30, 60}— closed set perDistributedRenderConfig.format === "webm"—plan()refuses webm.hdr === true— distributed mode is SDR-only at v1.
Both modes use the fixture's authored minPsnr as the per-test
threshold — distributed must clear the same quality bar in-process
clears against the same frozen baseline. (Internal contract: distributed
vs in-process renders of the same fixture should clear 50 dB PSNR
against each other within the same Docker image. Against the frozen
committed baseline, neither mode reaches that consistently due to
shared encoder/JPEG-capture jitter — that's why the fixture's authored
threshold gates here, not the 50 dB contract value.) An absolute 10 dB
pathology floor catches fully-black-output regressions when a fixture
authors a permissive threshold. A distributed failure at the fixture's
own threshold means the distributed pipeline has drifted — file an
issue rather than relaxing the fixture.
--update is incompatible with --mode=distributed-simulated: the
in-process renderer is the source of truth for baselines, and the
distributed mode's job is to verify the contract against the same
baseline.
Validating PR 4.1 (the harness mode itself)
The smallest fixtures (font-variant-numeric, many-cuts) are sufficient
to verify the mode plumbing end to end:
docker build -t hyperframes-producer:test -f Dockerfile.test .
# In-process: existing behavior, unchanged.
bun run --cwd packages/producer docker:test font-variant-numeric
bun run --cwd packages/producer docker:test many-cuts
# Distributed-simulated: same baselines, distributed pipeline.
bun run --cwd packages/producer docker:test font-variant-numeric -- --mode=distributed-simulated
bun run --cwd packages/producer docker:test many-cuts -- --mode=distributed-simulated
Both modes must pass at each fixture's authored minPsnr against the
existing baseline. If --mode=distributed-simulated fails where
--mode=in-process passes, the distributed primitive has a regression —
file an issue rather than relaxing the fixture's threshold.
Distributed-only fixtures
Fixtures under tests/distributed/<name>/ are authored specifically for
the distributed pipeline. They follow the same meta.json schema as the
top-level fixtures, but they always set chunkSize / maxParallelChunks
so a plan() over the fixture produces N>1 chunks. Each fixture
exercises one of:
- per-format chunk-boundary correctness (mp4 H.264, mp4 H.265, ProRes, png-sequence)
- per-adapter chunk-seam state preservation (GSAP, Anime.js, Three.js, Lottie, CSS, WAAPI)
Each distributed fixture covers one or more equivalence axes — see the
meta.json description field for what a given fixture is locking in.
Fixture pattern (4.2 onward)
Each tests/distributed/<name>/ fixture has the same structure as a
top-level fixture (meta.json + src/index.html + output/output.mp4).
Differences worth knowing:
renderConfig.chunkSizeis required — pick a value that yields N≥2 chunks for your fixture's frame count (e.g. 60 frames atchunkSize: 15produces N=4). Without this the fixture renders in a single chunk and never exercises the seam.- The fixture's ID on the CLI is just
<name>(nodistributed/prefix).bun run --cwd packages/producer docker:test mp4-h264-sdrworks the same as for a top-level fixture. - The
distributedtag is informational — it doesn't gate any tag-based filter today. Add it so the fixture is easy to find by tag. - The composition should stress state continuity across the chunk seams: an animation crossing a seam, a counter, a rotation. A fully-static composition would pass even if chunk-boundary state was broken.
- Baselines must be generated inside Docker — see the section above.
The baseline is rendered by the in-process renderer (the source of
truth for golden output);
--mode=distributed-simulatedis validated against the same baseline.
Tags
Common tags values control which fixtures the default bun test
invocation runs. --exclude-tags transparency (the default for
bun test) skips webm/png-sequence alpha fixtures that need a working
chrome-headless-shell alpha pipeline.