Chess.mkv.mp4 -

The system reads the .mp4 footer, identifies the streams, and plays it natively on almost any modern device.

Modern, robust media players like VLC or MPC-HC will ignore the .mp4 extension, scan the file header, detect that it is actually a Matroska container, and play it without issue. Native players (like QuickTime on macOS) may fail to open it. 💡 Conclusion CHESS.mkv.mp4

The secondary (and active) extension indicating an MPEG-4 Part 14 container. 2. Container vs. Codec The system reads the