Filenames starting with "AgAD" are frequently associated with , where media files sent through the app are assigned unique strings before being cached or downloaded. If you found this in a downloads folder, it is highly likely a video shared via a messaging app. Suggestions for MKV files - ExifTool by Phil Harvey
MKV files can store extensive tagging information , including "Track Names," "Titles," and "Chapters". AgADOQgAArdTsFY.mkv
While some older devices may find MP4 files easier to play , MKV is widely considered the industry standard for high-quality video storage and multi-language support. How to Identify the Content While some older devices may find MP4 files
As an MKV (Matroska Video) file, this is a multimedia container designed to hold an unlimited number of video, audio, picture, or subtitle tracks in one file. Key characteristics of this format include: It is a free-to-use, non-proprietary standard. including "Track Names