ftyp
ftyp, or the File Type Box, is a metadata box used by the ISO Base Media File Format (ISOBMFF) and its derivatives, such as MP4, M4A, and 3GP. It is typically the first box in a file and provides a quick means for software to identify the file type and determine compatibility with various features and codecs.
The box contains a size field and the ASCII code 'ftyp' that marks the box type, followed
Commonly seen major brands include isom and mp41/mp42, with compatible_brands often listing isom, iso2, avc1, mp41,
In practice, the ftyp box helps software decide how to handle the file, select appropriate decoders, and