feat(producer): enable webm in distributed mode via concat-copy (#951)

* 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> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-09-04 16:42:27 +00:00 · 2026-05-19 02:46:21 -04:00
parent 07de7e61ed
commit 21f5066832
12 changed files with 405 additions and 110 deletions
@@ -460,3 +460,58 @@ describe("plan() — codec knob", () => {
    expect((caught as Error).message).toMatch(/codec must be "h264" or "h265"/);
  });
 });
+
+describe("plan() — webm format (distributed VP9)", () => {
+  const TIMEOUT_MS = 30_000;
+
+  it(
+    'maps `format: "webm"` to libvpx-vp9-software + yuva420p',
+    async () => {
+      // Webm is distributed-supported via closed-GOP concat-copy (PR 8.1
+      // proved the contract; this test pins the plan-time encoder choice).
+      // yuva420p preserves the format's reason for existing — alpha video
+      // for web playback over colored backgrounds.
+      const planDir = join(runRoot, "plan-webm-vp9");
+      mkdirSync(planDir, { recursive: true });
+      const result = await plan(
+        projectDir,
+        { fps: 30, width: 320, height: 240, format: "webm" },
+        planDir,
+      );
+      expect(result.format).toBe("webm");
+
+      const encoder = JSON.parse(
+        readFileSync(join(planDir, "meta", "encoder.json"), "utf-8"),
+      ) as Record<string, unknown>;
+      expect(encoder.encoder).toBe("libvpx-vp9-software");
+      expect(encoder.pixelFormat).toBe("yuva420p");
+      // Closed-GOP must be on so concat-copy at assemble time works.
+      // gopSize equals the chunkSize so every chunk's first frame is a
+      // keyframe with no alt-ref references reaching back across seams.
+      expect(encoder.closedGop).toBe(true);
+      expect(encoder.gopSize).toBe(encoder.chunkSize);
+    },
+    TIMEOUT_MS,
+  );
+
+  it("rejects `codec` with format=webm", async () => {
+    // webm is always libvpx-vp9 — same shape as mov (always ProRes 4444).
+    // A JS caller building config from JSON who passes `codec: "vp8"` or
+    // `codec: "av1"` must hit a typed error, not silently encode VP9.
+    const planDir = join(runRoot, "plan-webm-bad-codec");
+    mkdirSync(planDir, { recursive: true });
+    let caught: unknown;
+    try {
+      await plan(
+        projectDir,
+        // @ts-expect-error — runtime check is the test's purpose.
+        { fps: 30, width: 320, height: 240, format: "webm", codec: "vp8" },
+        planDir,
+      );
+    } catch (err) {
+      caught = err;
+    }
+    expect(caught).toBeInstanceOf(Error);
+    expect((caught as Error).message).toMatch(/codec.*only valid for format="mp4"/);
+  });
+});