From 4be81b4fb481e234f81256a3cec4c99bde21bf71 Mon Sep 17 00:00:00 2001
From: James Russo <james.russo@heygen.com>
Date: Mon, 22 Jun 2026 09:53:04 -0700
Subject: [PATCH] fix(producer): inline base64 frames in injector to unblock
 video-heavy renders (#1630)
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* fix(producer): inline base64 frames in injector to unblock video-heavy renders

The URL-served frame path (PR #596) hands each injected `<img>` a fileServer URL
instead of a base64 data URI, on the theory that shipping a short URL through
`page.evaluate` beats shipping a multi-MB base64 string per frame. That holds
when the fileServer is otherwise idle.

But on video-heavy compositions, the same fileServer also serves every
`<video>.src`. The runtime's drift-recovery branch (`runtime/media.ts:294-302`)
issues `el.load()` on the underlying `<video>` during seeks, kicking off
full-file downloads that occupy the fileServer's single Node event loop (it
uses `readFileSync` and offers no `Accept-Ranges`). The injector's
`<img>.decode()` then queues behind those video fetches and is never serviced
before puppeteer's protocol timeout fires, surfacing as
`Runtime.callFunctionOn timed out` in `capture_streaming`.

Reproducer (30 × 32 MB videos / 90 s comp / 8-core / 30 GB host):

  baseline (broken corpus)            537 s   render fails
  baseline (corpus-fixed)             428 s   render fails
  this fix (drop frameSrcResolver)    121 s   render succeeds, 69 MB MP4

Control corpus (30 × 1.6 MB / 60 s) shows no regression: 137 s with this
change vs ~135 s on \`main\`. The \`createCompiledFrameSrcResolver\` builder and
the \`frameSrcResolver\` option stay in the codebase, just unused for now —
re-enabling them behind a proper gate ("only use URL-served frames when the
page has zero fileServer-bound \`<video>.src\` traffic") is a follow-up. The
cache memory ceiling (\`frameDataUriCacheBytesLimitMb\`, default 1500 MB above
8 GB hosts) already bounds the cost of base64 inlining.

— Jerrai

* refactor(producer): drop unused frameSrcResolver builder import in render orchestrator

Followup to the previous commit. The void-call and the
`createCompiledFrameSrcResolver` import in `renderOrchestrator.ts` were left
behind as a no-op breadcrumb for the future gating PR. Code review (PR #1630)
correctly flagged this as dead code — the builder is a pure factory with no
side effects, so calling it and discarding the result is just wasted CPU.
Remove both and explain in the in-source comment where the builder still
lives, so the gating PR knows where to re-import from.

— Jerrai
---
 .../src/services/renderOrchestrator.ts        | 39 +++++++++++++++----
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/packages/producer/src/services/renderOrchestrator.ts b/packages/producer/src/services/renderOrchestrator.ts
index 5670de9ab..db2f22020 100644
--- a/packages/producer/src/services/renderOrchestrator.ts
+++ b/packages/producer/src/services/renderOrchestrator.ts
@@ -79,12 +79,7 @@ import {
   VIRTUAL_TIME_SHIM,
 } from "./fileServer.js";
 import { defaultLogger, type ProducerLogger } from "../logger.js";
-import {
-  createCompiledFrameSrcResolver,
-  createMemorySampler,
-  type MemorySampler,
-  updateJobStatus,
-} from "./render/shared.js";
+import { createMemorySampler, type MemorySampler, updateJobStatus } from "./render/shared.js";
 import { buildRenderErrorDetails, cleanupRenderResources, safeCleanup } from "./render/cleanup.js";
 import { normalizeErrorMessage } from "../utils/errorMessage.js";
 import { formatCaptureFrameName } from "../utils/paths.js";
@@ -1210,12 +1205,40 @@ export async function executeRenderJob(
       videoMetadataHints,
       skipReadinessVideoIds: videoReadinessSkipIds,
     });
-    const frameSrcResolver = createCompiledFrameSrcResolver(compiledDir);
+    // The URL-served frame path (PR #596) hands each injected `<img>` a
+    // fileServer URL instead of a base64 data URI, on the theory that
+    // shipping a short URL through `page.evaluate` beats shipping a
+    // multi-MB base64 string per frame. That holds when the fileServer
+    // is otherwise idle — but on video-heavy compositions, the same
+    // fileServer also serves every `<video>.src`. The runtime's
+    // drift-recovery branch (`runtime/media.ts:294-302`) issues
+    // `el.load()` on the underlying `<video>` during seeks, kicking off
+    // full-file downloads that occupy the fileServer's single Node
+    // event loop (it uses `readFileSync` and offers no `Accept-Ranges`).
+    // The injector's `<img>.decode()` then queues behind those video
+    // fetches and is never serviced before puppeteer's protocol timeout
+    // fires (`Runtime.callFunctionOn timed out`).
+    //
+    // Repro: synth 30 × 32 MB videos / 90 s comp on an 8-core / 30 GB
+    // host = 537 s wall (broken corpus) / 428 s (corpus-fixed), every
+    // render fails. Disabling the resolver (force base64-inline) gives
+    // 1:59 (119 s) wall and a clean MP4 on the same comp, with no
+    // regression on the 30 × 1.6 MB control corpus (137 s vs 135 s
+    // baseline).
+    //
+    // Until this is properly gated (e.g. only enable URL-served when the
+    // page has zero fileServer-bound `<video>.src` traffic), the inline
+    // path is the safe default. The cache memory ceiling
+    // (`frameDataUriCacheBytesLimitMb`, default 1500 MB above 8 GB
+    // hosts) already bounds the cost. `createCompiledFrameSrcResolver`
+    // and the `frameSrcResolver` option remain in their respective
+    // modules (`packages/producer/src/services/render/shared.ts`,
+    // `packages/engine/src/services/videoFrameInjector.ts`); the gating
+    // PR will re-import the builder here.
     const createRenderVideoFrameInjector = (): BeforeCaptureHook | null =>
       createVideoFrameInjector(frameLookup, {
         frameDataUriCacheLimit: cfg.frameDataUriCacheLimit,
         frameDataUriCacheBytesLimitMb: cfg.frameDataUriCacheBytesLimitMb,
-        frameSrcResolver,
       });
 
     let captureCalibration: