WebM Merge Panel (cPanel)

INSTALL
1) Upload this folder to your hosting:
   public_html/merge/

2) Ensure these folders are writable:
   public_html/merge/tmp
   public_html/merge/out

3) Requirements:
   - ffmpeg installed and executable
   - PHP shell_exec enabled
   - PHP cURL enabled

USAGE
- Open: https://YOURDOMAIN.com/merge/
- Paste:
  1) Video-only URL (webm)
  2) Audio-only URL (webm)
- Click merge. You will get a neon download button.

TUNING FOR SMALLER OUTPUT
- CRF: 34 (default). Increase to 38-42 for smaller size.
- max width: 1280 (default). Reduce to 854 or 720 for smaller size.
- audio bitrate: 48 kbps (default). Reduce to 32 for smaller size.

SECURITY NOTE
- For production, consider whitelisting allowed domains for URLs.
- Consider adding rate-limits, auth, and cleanup (cron) for old files.

FILES
- index.php  (UI)
- merge.php  (download + merge + compress)
- out/       (outputs)
- tmp/       (temporary)