Quicktime — Extension !!top!!

For modern systems, tools like ffprobe (from FFmpeg) can identify the FourCC or component type of a track. Example:

ffprobe -show_streams mystery.mov | grep codec_name If you see codec_name=svq3 (Sorenson Video 3) or qdm2 (QDesign Music 2), you’ve found an extension-dependent file. QuickTime extensions were a triumph of component-based design long before microservices or plugins became fashionable. They allowed a single media framework to support everything from camcorder capture to interactive VR to 3D rendering—without requiring the whole system to be rewritten. quicktime extension

: QuickTime extensions were the unsung heroes and occasional villains of early digital video. They are now fossils of a bygone era—but fossils that still hold the keys to thousands of hours of unplayable media, waiting for the right codec to bring them back to life. Further reading: Inside QuickTime (Apple Technical Documentation, 1997); “The QuickTime File Format” (1998); FFmpeg’s QuickTime codec reverse-engineering notes. For modern systems, tools like ffprobe (from FFmpeg)