Check/repair mp4 and other video files.

[bluenite]

What is the best way to check video files downloaded from yt or similar servers to see if they are playable or ok? Do you have a tip for a program that can do this? There are lots of them (here too), but which one is worth recommending according to the experts?
Thanks in advance
Peter

[lomero]

ffmpeg allow that
play your video (before need to download!). if has some defect, you can use this:

ffmpeg -i video.mp4 -c copy output.mp4

this solve some issue. but without re-encoding
if your defect is more serious need re-encoding or also need other app (almost all not free)

[ridibunda]

Open the video file with MediaInfo. If MediaInfo reports a complete duration, it is playable then. - According to my experiences.

If you downloaded a corrupted mp4 file, forget repairing

https://forum.videohelp.com/threads/404908-How-to-repair-MP4-files-with-corrupted-frames

You will lose the entire corrupted zone in each case (with or without re-encoding). That might be only 10-15 seconds or much more, depending on the file. And you will have to re-synch the audio with the new, shortened video.

Windows can report a complete duration in corrupted MP4 files, too. That can deceive you. You must look at what MediaInfo says.