: This is the default player for .m4v files on macOS.
: If a player doesn't recognize it, you can often safely rename the extension from .m4v to .mp4 as they are nearly identical formats. 552.m4v - BayFiles
Based on the file naming convention, appears to be a video file from Apple's Worldwide Developers Conference (WWDC) . Specifically, Session 552 is a known presentation from WWDC 2011 titled "Advanced Scroll View Techniques" or similar technical content for iOS/macOS developers. Important Safety Note on BayFiles : This is the default player for
If you are looking for the technical content originally contained in that video, do not use third-party file-sharing mirrors. Instead, use these official or reputable developer resources: 552.m4v - BayFiles