fix(producer): preserve runtime audio variables in distributed plans (#2725)

* fix(producer): preserve runtime audio variables in distributed plans

* fix(producer): prefer runtime duration for volume sampling

packages/producer/src/services/distributed/plan.test.ts

@@ -81,6 +81,25 @@ describe("distributed warning policy", () => {
   });
 });
 
+describe("distributed synthetic render job", () => {
+  it("threads render variables into the plan browser probe job", () => {
+    const variables = {
+      voiceoverSrc: "assets/voiceover.wav",
+      narrationDurationSeconds: 56.738,
+    };
+    const job = buildSyntheticRenderJob({
+      fps: { num: 30, den: 1 },
+      format: "mp4",
+      quality: "high",
+      hdrMode: "force-sdr",
+      entryFile: "index.html",
+      variables,
+    });
+
+    expect(job.config.variables).toEqual(variables);
+  });
+});
+
 describe("resolveChunkPlan", () => {
   it("returns 1 chunk when totalFrames fits in configChunkSize", () => {
     const result = resolveChunkPlan(60, 240, 16);

packages/producer/src/services/distributed/plan.ts

@@ -782,6 +782,7 @@ export async function plan(
     entryFile: config.entryFile ?? "index.html",
     logger: config.logger,
     producerConfig: cfg,
+    variables: config.variables,
   });
   const entryFile = config.entryFile ?? "index.html";
   const htmlPath = join(projectDir, entryFile);

packages/producer/src/services/distributed/shared.ts

@@ -106,6 +106,8 @@ export interface SyntheticRenderJobInput {
   entryFile: string;
   logger?: ProducerLogger;
   producerConfig?: RenderConfig["producerConfig"];
+  /** Render-time overrides consumed by the plan browser probe. */
+  variables?: RenderConfig["variables"];
 }
 
 /**
@@ -133,6 +135,7 @@ export function buildSyntheticRenderJob(input: SyntheticRenderJobInput): RenderJ
     hdrMode: input.hdrMode,
     strictness: input.strictness,
     producerConfig: input.producerConfig,
+    variables: input.variables,
   };
   return createRenderJob(renderConfig);
 }

packages/producer/src/services/htmlCompiler.test.ts

@@ -1763,11 +1763,11 @@ h1 { font-size: 2rem; }`;
 });
 
 describe("discoverAudioVolumeAutomationFromTimeline", () => {
-  it("samples video-derived audio volume without firing GSAP callbacks", async () => {
+  it("prefers runtime duration over stale data-end while sampling video-derived audio", async () => {
     class TestAudioElement {}
     class TestVideoElement {
       id = "bg-video";
-      dataset = { start: "0", duration: "1", volume: "0" };
+      dataset = { start: "0", end: "0.25", duration: "1", volume: "0" };
       volume = 0;
     }
 

packages/producer/src/services/htmlCompiler.ts

@@ -2134,10 +2134,10 @@ export async function discoverAudioVolumeAutomationFromTimeline(
         const endAttr = Number.parseFloat(el.dataset.end ?? "");
         const durationAttr = Number.parseFloat(el.dataset.duration ?? "");
         const end =
-          Number.isFinite(endAttr) && endAttr > start
+          Number.isFinite(durationAttr) && durationAttr > 0
-            ? endAttr
-            : Number.isFinite(durationAttr) && durationAttr > 0
             ? start + durationAttr
+            : Number.isFinite(endAttr) && endAttr > start
+              ? endAttr
               : duration;
         const sampleStart = Math.max(0, start);
         const sampleEnd = Math.min(duration, end);

packages/producer/src/services/render/shared.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from "bun:test";
+import { resolveBrowserMediaEnd } from "./shared.js";
+
+describe("resolveBrowserMediaEnd", () => {
+  it("prefers a runtime duration over a stale compiler-clamped end", () => {
+    expect(resolveBrowserMediaEnd(0, 5.04, 56.738)).toBe(56.738);
+  });
+
+  it("projects a runtime duration from the browser-local start", () => {
+    expect(resolveBrowserMediaEnd(2, 7.04, 56.738)).toBe(58.738);
+  });
+
+  it("falls back to data-end when runtime duration is unavailable", () => {
+    expect(resolveBrowserMediaEnd(0, 5.04, Number.NaN)).toBe(5.04);
+    expect(resolveBrowserMediaEnd(0, 5.04, 0)).toBe(5.04);
+  });
+});

packages/producer/src/services/render/shared.ts

@@ -53,6 +53,19 @@ export interface CompositionMetadata {
  */
 export const BROWSER_MEDIA_EPSILON = 0.0001;
 
+/**
+ * Resolve the browser/runtime end for a media element.
+ *
+ * `data-end` is compiler-generated metadata, while `data-duration` is the
+ * authored/runtime value. A render variable can replace a placeholder source
+ * and update `data-duration` after compilation, leaving the compiler-clamped
+ * `data-end` stale. Prefer the live duration when present so the audio/video
+ * extraction window follows the runtime media slot.
+ */
+export function resolveBrowserMediaEnd(start: number, end: number, duration: number): number {
+  return Number.isFinite(duration) && duration > 0 ? start + duration : end;
+}
+
 export function writeFileExclusiveSync(path: string, data: NodeJS.ArrayBufferView | string): void {
   try {
     writeFileSync(path, data, { flag: "wx", mode: 0o600 });

packages/producer/src/services/render/stages/probeStage.test.ts

@@ -103,6 +103,8 @@ mock.module("../../htmlCompiler.js", () => ({
 mock.module("../shared.js", () => ({
   BROWSER_MEDIA_EPSILON: 0.0001,
   projectBrowserEndToCompositionTimeline: () => 0,
+  resolveBrowserMediaEnd: (_start: number, end: number, duration: number) =>
+    Number.isFinite(duration) && duration > 0 ? _start + duration : end,
   writeCompiledArtifacts: () => {},
 }));
 

packages/producer/src/services/render/stages/probeStage.ts

@@ -55,6 +55,7 @@ import type { ProducerLogger } from "../../../logger.js";
 import {
   BROWSER_MEDIA_EPSILON,
   projectBrowserEndToCompositionTimeline,
+  resolveBrowserMediaEnd,
   writeCompiledArtifacts,
   type CompositionMetadata,
 } from "../shared.js";
@@ -454,7 +455,7 @@ export async function runProbeStage(input: ProbeStageInput): Promise<ProbeStageR
               const projectedEnd = projectBrowserEndToCompositionTimeline(
                 existing.start,
                 el.start,
-                el.end,
+                resolveBrowserMediaEnd(el.start, el.end, el.duration),
               );
               if (
                 projectedEnd > 0 &&
@@ -482,7 +483,7 @@ export async function runProbeStage(input: ProbeStageInput): Promise<ProbeStageR
               id: el.id,
               src,
               start: el.start,
-              end: el.end,
+              end: resolveBrowserMediaEnd(el.start, el.end, el.duration),
               mediaStart: el.mediaStart,
               loop: el.loop,
               hasAudio: el.hasAudio && !el.muted,
@@ -500,7 +501,7 @@ export async function runProbeStage(input: ProbeStageInput): Promise<ProbeStageR
               const projectedEnd = projectBrowserEndToCompositionTimeline(
                 existing.start,
                 el.start,
-                el.end,
+                resolveBrowserMediaEnd(el.start, el.end, el.duration),
               );
               if (
                 projectedEnd > 0 &&
@@ -527,7 +528,7 @@ export async function runProbeStage(input: ProbeStageInput): Promise<ProbeStageR
               id: el.id,
               src,
               start: el.start,
-              end: el.end,
+              end: resolveBrowserMediaEnd(el.start, el.end, el.duration),
               mediaStart: el.mediaStart,
               layer: 0,
               volume: el.volume,