Subtitles are clips that contain text and other information.
Subtitles can be flagged to change their behavior. They can be flagged as forced, italic, raised, and more.
Text
Stores the editable text. It consists of paragraphs, lines and runs, as well as inline formatting.
Paragraph
It is a group of text lines.
It is possible to have more than one paragraph with different formatting in a subtitle.
Read more about this here.
Line
It is a group of characters.
If segments of the line have different formatting, the line will be divided in several text runs.
Lines can be empty too.
Run
It is a collection of characters with the same formatting.
Bytes
Stores binary information.
It may be closed captions bytes, or blu-ray encoded text.
Subpicture
Points to an image file. It also stores the position of the picture.
Reference text
Stores a text that is used as reference. This is usually the original language to be translated.