Display flags

A 32-bit integer containing flags that describe how the subtitle text should be drawn.

Overview

The following flags are defined:

Vertical placement: Controls vertical placement of the subtitle text. If this flag is set, the subtitle media handler uses the top coordinate of the display bounds of the override 'tbox' text box to determine the subtitle’s vertical placement as described in Subtitle track header size and placement. Otherwise, the subtitle displays at the bottom of the video. This flag’s value is 0x20000000.
Some samples are forced: Indicates whether any subtitle samples contain forced atoms. If this flag is set, at least one sample contains a forced ('frcd') atom as described in Subtitle sample data. This flag’s value is 0x40000000.
All samples are forced: If this flag is set, the subtitle media handler treats all samples as forced subtitles, regardless of the presence or absence of a 'frcd' atom. This flag’s value is 0x80000000. If this flag is set, the Some Samples Are Forced flag must also be set (making 0xC0000000).