: The prefix AgAD... is a common naming convention for media uploaded to Telegram's servers. When a user sends a video without a caption, the platform assigns it a unique ID like this to manage it in its cloud database.
: The .mkv extension stands for Matroska , an open-source container that can hold multiple video, audio, and subtitle tracks in a single file. AgADhQADyTeAVw.mkv
If you have this file and want to know what it is without opening it, you can try: : The prefix AgAD
: If it is a snippet of a known movie or show, you can take a screenshot and use an image search to identify the original work. The context of that conversation is usually the
: Look back at the Telegram chat or channel where the file was originally posted. The context of that conversation is usually the only way to identify its content.
Are you trying to within this file, or