Describe the bug

The following articles have videos that could not be played in Firefox on any platform because they’re encoded as HEVC/H.265:

• Four new CSS features for smooth entry and exit animations
• New in Chrome 117

To Reproduce

Steps to reproduce the behavior:

1. Go to the article in the latest Firefox (119)
2. See “No video with supported format found” error

Expected behavior

Videos available in Firefox

Screenshots

Desktop:

• OS: macOS 14.0
• Browser: Firefox
• Version: 119.0 (64-bit)

Smartphone:

• Device: Pixel 3a
• OS: Android 12
• Browser: Firefox
• Version: 119.0

Additional context

Firefox doesn’t support HEVC/H.265 format yet. For better compatibility, it’s better to encode videos to H.264.