2776mp4

: Combining a 1080p video with a 720p video might cause stretching or black bars.

Are you trying to (like 2776.mp4, 2777.mp4) or just repair a single corrupted file ? What is H.264? | Advanced Video Coding (AVC) - Cloudflare 2776mp4

: If you have many pieces and want to join them without losing quality (lossless), use the FFmpeg command-line tool. You can use the "concat" command to stitch files with the same codec (like H.264/AVC) together instantly. : Combining a 1080p video with a 720p