[BUG] FFmpeg worker error prevents video export after reframing

[Shubham-chaudhary07]

Bug description
After uploading and reframing a video, the export process fails due to an FFmpeg worker error. The processed video cannot be exported or downloaded successfully.

Steps to reproduce
Steps to reproduce the behavior:

1. Go to the website
2. Upload a video
3. Apply reframing settings/preset
4. Click on the Export button
5. See FFmpeg worker error / failed export

Expected behavior
The video should process correctly and export/download successfully after reframing.

Actual behavior
The export process fails and no final video is generated. An FFmpeg worker error appears during processing.

Browser and OS info

• OS: Windows 11
• Browser: Chrome
• Version: Latest stable version

Video format (if relevant)

• Input video format: MP4
• Export preset used: portrait-3-4
• File size: Depends on uploaded file

Screenshots/screen recording

[github-actions]

👋 Thanks for opening an issue, @Shubham-chaudhary07!

Our maintainers will review this shortly 🚀

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Architecture notes

Reframe is a static Next.js app with output: "export". Key points:

• All video processing uses FFmpeg.wasm (client-side, no server)
• headers() in next.config.ts won't work — use vercel.json instead
• not-found.tsx requires public/404.html + vercel.json routes config

Happy contributing! ⭐ Star the repo if you find it useful!

[Shubham-chaudhary07]

"I'd like to work on this — contributing under GSSoC'26"

/assign

[github-actions]

Hey @Shubham-chaudhary07, this issue has been assigned to you! 🎉 Please make progress within 5 days or it will be automatically unassigned due to inactivity.