Because the file lacks a recognized extension. Rename to .mp4 . If still unsupported, the file may use an old or less common codec. Use VLC for Mobile.

Yes, after renaming to .mp4 . YouTube will recompress it, so to retain best quality, upload at the original bitrate (20-30 Mbps for FHD) and avoid re-encoding beforehand.

refers to a resolution of 1920 × 1080 pixels. It is the standard for high-quality streaming and digital content, providing crisp visuals suitable for screens ranging from smartphones to large television monitors. When content is labeled under fhdarchivesone405 , it implies a focus on storing high-fidelity video files, minimizing compression artifacts, and retaining original detail. Why "2mp4" is the Best Choice for Storage

This creates a file with superior compression while remaining visually indistinguishable from the original:

Avoid nearest-neighbor scaling – it ruins the “best” quality.