Sone248subjavhdtoday015730 Min Fixed -

ffmpeg -i broken.mp4 -t 30 -c:v libx264 -c:a aac output.mp4 (replace 30 with true length in seconds)

ffmpeg -i broken.mp4 -c copy fixed.mp4 If remuxing doesn’t work, re-encode a short segment: sone248subjavhdtoday015730 min fixed

Use ffprobe (part of FFmpeg):