Preselection components and tag attributes
The preselectionComponents and tag attributes must
be included in Preselection elements.
The preselectionComponents attribute contains a white space–separated
list of the IDs of the adaptation sets that the preselection refers to. The ID of the
adaptation set that contains the main audio component must be the first one in the
list.
The tag attribute corresponds to the presentation_id in
the ac4_presentation_v1_dsi of the associated Dolby AC-4
presentation. It provides the unique binding of the preselection to the Dolby AC-4 presentation.
library_booksNote: The
presentation_id field was formerly also known as
presentation_group_index. Other specifications might still refer to
this field as presentation_group_index.