1_4922468623605302054.m4v - | Bayfiles

Filenames starting with 1_ followed by a long string of digits are characteristic of files downloaded from Telegram or similar encrypted messaging services that rename files upon upload.

Open it with VLC Media Player or MPC-HC. These players bypass most container issues and can play the video even if it's just a renamed MP4. 1_4922468623605302054.m4v - BayFiles

If your device doesn't recognize it, you can often simply rename the .m4v to .mp4 without damaging the file. Filenames starting with 1_ followed by a long