Please help! Extreme Urgency. Legal files.

[jdunnhvac]

My brother was beat up by the police in my town arrested and charged with resisting and trespassing a place he already willingly walked out of, while recording me being roughed up by them, being arrested for trespassing at a bowling alley I paid to be at, and have been attending for 25 years. We were asked to leave got a little carried away on the drinking and trying to line up a ride home, we didn't leave fast enough apparently, between our scattered belongings and trying to line up a friend or uber.

Luckily, I was able to obtain all the footage from the bowling alley, which they only keep for 5 days, we are going into day 5 and this can happen at any time.

However, when I was finally able to get home from work to review this, The small AVI files play fine. The small .mp4 files play fine and all the long videos that say 1,000,000+KB are giving me this dialogue or similar in anything I attempt to open the file in; "This file isn't playable. That might be because the file type is unsupported, the file extension is incorrect, or the file is corrupt."

I have tried various fixes, looking into data recovery software, but not sure if I am missing something simple and what the best route would be and if it is data recovery, what are good software options to use that may help with this issue.

I have Windows 10 and the data copied onto two brand new 64 GB SanDisk flashdrives.

[NikolayIslentev]

If source of that file was a Chinese IP-camera, it may need special converter/player to view. Try different media players.

[fzabkar]

Examine the header of the unplayable file with a hex editor, eg HxD (freeware). Save the first few KB to a file and upload it here.