From 6dbdac81181371c75646ea3f8f5254192d29db3c Mon Sep 17 00:00:00 2001
From: James <james.russo@heygen.com>
Date: Thu, 14 May 2026 23:49:12 +0000
Subject: [PATCH] fix(producer): normalize default-format check + carry
 no-audio rationale to mp4-h265-sdr fixture
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Address @vanceingalls review on #851:

1. validateMetadata's codec/format check read 'rc.codec !== undefined &&
   rc.format !== undefined && rc.format !== "mp4"'. The behavior was
   correct (omitted format defaults to mp4 downstream so codec is legal)
   but relied on the reader knowing that default. Normalize 'effectiveFormat
   = rc.format ?? "mp4"' before the comparison so the intent reads
   directly.

2. The mp4-h264-sdr sibling carries inline rationale for the no-audio
   choice (AAC frame quantization extends container.duration past
   nb_frames/fps and trips the harness PSNR sampler) and the chunk-seam
   mapping (crossfade window 0.9-1.1s straddles frame 30). mp4-h265-sdr
   stripped both. Carry them back so the two fixtures stay parallel.

🤖 Generated with [Claude Code](https://claude.com/claude-code)
---
 packages/producer/src/regression-harness.ts          |  9 ++++++++-
 .../tests/distributed/mp4-h265-sdr/src/index.html    | 12 ++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/packages/producer/src/regression-harness.ts b/packages/producer/src/regression-harness.ts
index a540fc31e..776d14145 100644
--- a/packages/producer/src/regression-harness.ts
+++ b/packages/producer/src/regression-harness.ts
@@ -266,7 +266,14 @@ function validateMetadata(meta: unknown): TestMetadata {
       "meta.json: 'renderConfig.codec' must be 'h264' or 'h265' (or omit for the format's default)",
     );
   }
-  if (rc.codec !== undefined && rc.format !== undefined && rc.format !== "mp4") {
+  // Normalize the implicit default before comparing so a fixture that
+  // omits `format` (which defaults to "mp4" everywhere downstream) doesn't
+  // get accidentally treated as "format is missing, so codec is illegal."
+  // The previous formulation `rc.format !== undefined && rc.format !== "mp4"`
+  // worked but relied on the reader knowing the default; this reads the
+  // intent more directly.
+  const effectiveFormat = (rc.format as string | undefined) ?? "mp4";
+  if (rc.codec !== undefined && effectiveFormat !== "mp4") {
     throw new Error(
       `meta.json: 'renderConfig.codec' is only valid for format='mp4' (got format=${JSON.stringify(
         rc.format,
diff --git a/packages/producer/tests/distributed/mp4-h265-sdr/src/index.html b/packages/producer/tests/distributed/mp4-h265-sdr/src/index.html
index 710a6ead3..ce638a515 100644
--- a/packages/producer/tests/distributed/mp4-h265-sdr/src/index.html
+++ b/packages/producer/tests/distributed/mp4-h265-sdr/src/index.html
@@ -84,9 +84,21 @@
         <circle cx="24" cy="24" r="18" fill="none" stroke="#6366f1" stroke-width="4" />
         <circle cx="24" cy="24" r="6" fill="#6366f1" />
       </svg>
+      <!--
+        No audio element on purpose: AAC frame quantization pads a 2-second
+        silent track past 2.0s of container time, which extends format.duration
+        past nb_frames / fps and trips the harness PSNR sampler at the very
+        last checkpoint. The chunk-boundary contracts this fixture pins are
+        video-only; omitting audio keeps container duration == 2.0s exactly.
+        (Same rationale as mp4-h264-sdr.)
+      -->
     </div>
 
     <script>
+      // Same chunk-seam stressors as the mp4-h264-sdr sibling: crossfade
+      // straddles the frame-30 seam (0.9-1.1s = frames 27-33); continuous
+      // icon rotation makes per-frame angle a pure function of seek-position
+      // so virtual-clock drift surfaces as discontinuity at frame 15/30/45.
       const tl = gsap.timeline({ paused: true });
       window.__timelines = window.__timelines || {};
       window.__timelines["main-comp"] = tl;