ffmpeg -err_detect ignore_err -i input.mp4 -c copy output.mp4
VLC has built-in features to re-index and re-encode corrupted files. Method A: Auto-Repair (Permanent) Preferences Input / Codecs Damaged or incomplete AVI file and select Always fix Method B: Transcoding (Re-packaging) Convert / Save Add your broken MP4 and click Convert / Save Set the profile to Video - H.264 + MP4 (MP3) Choose a destination and click 2. Use a "Reference Clip" (Untrunc Method) nippy user since 2015 mp4 fix
The very beginning of the file contains junk data (often where the "nippy user" string is embedded) instead of the standard MP4 file signatures ( ftypmp42 , mp41 , etc.). Method 1: The VLC Media Player Transcoding Trick (Easiest) ffmpeg -err_detect ignore_err -i input
Since "Nippy User Since 2015" is a legacy problem, you likely acquired these files from old hard drives, torrents from 2015-2016, or recovered USB sticks. To prevent recurrence: Method 1: The VLC Media Player Transcoding Trick
If you have an actual “nippy user since 2015” MP4, run:
In late 2015, the original "Nippy" (real name unknown) argued on the Doom9 forums that the MP4 specification allowed distributed moov atoms . They claimed this would reduce initial buffering on Pentium III machines. The community rejected the idea, but not before 500,000+ files were encoded with the preset.