From aebf865ec084f53e99ee32f5b0856071470a1d1f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20=C3=81ngel?= <miguel.sierra@heygen.com>
Date: Fri, 17 Apr 2026 00:18:07 +0200
Subject: [PATCH] fix(player): resolve iframe media src against iframe baseURI

_setupParentMedia scans the iframe for audio[data-start]/video[data-start]
and creates parallel media elements in the host document for playback.
It was reading the raw src attribute string and assigning it directly to
the host-document element, which then resolved relative URLs against the
studio root instead of the iframe. A composition using
`<audio src="assets/narration.wav">` would silently 404 in preview while
rendering fine.

Resolve against iframeEl.ownerDocument.baseURI before handing the URL to
_createParentMedia. Also prefer the raw src attribute on <source> over the
DOM-resolved .src so both codepaths go through the same resolution.
---
 packages/player/src/hyperframes-player.ts | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/packages/player/src/hyperframes-player.ts b/packages/player/src/hyperframes-player.ts
index 6bff51e8..94f52606 100644
--- a/packages/player/src/hyperframes-player.ts
+++ b/packages/player/src/hyperframes-player.ts
@@ -563,8 +563,15 @@ class HyperframesPlayer extends HTMLElement {
       );
 
       for (const iframeEl of mediaEls) {
-        const src = iframeEl.getAttribute("src") || iframeEl.querySelector("source")?.src;
-        if (!src) continue;
+        const rawSrc =
+          iframeEl.getAttribute("src") || iframeEl.querySelector("source")?.getAttribute("src");
+        if (!rawSrc) continue;
+
+        // Resolve against the iframe's baseURI. The parent-frame <audio>/<video>
+        // we create next lives in the host document, whose base URL differs from
+        // the iframe's — without this, a relative src like "assets/narration.wav"
+        // would resolve against the studio root and 404.
+        const src = new URL(rawSrc, iframeEl.ownerDocument.baseURI).href;
 
         const start = parseFloat(iframeEl.getAttribute("data-start") || "0");
         const duration = parseFloat(iframeEl.getAttribute("data-duration") || "Infinity");