Standard: MPEG-B
Part: 18

Editions

Edition - 1: Event Message Track Format for ISOBMFF

Publication Year: 0
Status: released
Motivations: The DASHEventMessageBox, defined in ISO/IEC 23009-1, is a box structure that may arise in streaming applications. However it is tricky to work with this box in ISOBMFF formatted media files, such as those based on the Common Media Track Format (CMAF). For instance, identifying active events at any point in the media track may require scanning of a large sub part of that track. In addition, it is not clear what happens to DashEventMessageBoxes when tracks are de-fragmented. Further, DashEventMessageBoxes cannot be de-multiplexed from track files based on ISO/IEC 23009-1 or ISO/IEC 23000-19.
Objectives: This AMD specifies alternative methods for carriage of DashEventMessageBox structures using ISOBMFF Timed metadata track format. This event message track format associates the timeline of the DashEventMessageBox to the ISOBMFF track timeline. The specified track format enables all common ISOBMFF processing such as multiplexing and de-fragmentation.