MatroskaSegment
What a Matroska file says about its own segment, its editions and their chapters, read as RFC 9559 defines them (#173).
A Matroska file can describe a timeline rather than a plain run of media. An ordered edition plays a list of chapters in its own order, a chapter can play a range or a whole edition of another file named by that file's uid, and segments can be chained through previousUid and nextUid. Anime releases share one opening and one ending file across a season this way, and a film can carry a theatrical and an extended cut as two editions of one file.
FFmpeg plays every such file as a plain file, and MediaSource.chapters is the plain reading of defaultEdition. This is what the file says, so that a player can build the timeline itself, as mpv and VLC do. Finding the files a segment links to, and playing them, is the player's work.
Segment UIDs are 32 lowercase hexadecimal digits, the 16 bytes of the UID in the order the file stores them, so two of them compare with ==. Edition and chapter UIDs are the file's unsigned 64-bit values carried in a Long, as Chapter.id carries them.
Constructors
Properties
The edition a player uses unless told otherwise: the first one flagged default, or the first one when none is (RFC 9559, section 20.1.2). Null when the file has no editions.
The editions of the file's Chapters element, in stored order. Empty when it has none.
The NextFilename of that segment, or null.
The PrevFilename of that segment, or null.
The PrevUUID of the segment this one follows when segments are chained, or null.