• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Chapter 4. BIFS: Scene Description > A Peek Ahead on BIFS

4.4. A Peek Ahead on BIFS

The following BIFS tools were being finalized at the time this book was written. They are specified in Amendments 1 and 2 to the second edition of the MPEG-4 Systems standard [MPEG4-1]. Their importance in terms of enabling applications justifies this anticipation.

4.4.1. Media Nodes

It was found quite early in the design of BIFS that the control features of some nodes inherited from VRML were impossible to use in the same way across all delivery scenarios. Rather than making the viewing experience for the same content different for different delivery scenarios, it was decided to restrict the semantics of the fields startTime and stopTime of the MovieTexture and Sound nodes and to design new, more complex nodes that would work the same way in all scenarios. These new nodes are MediaSensor, MediaControl, and MediaBuffer. These nodes are the only ones that deal with media time. The notion of stream segment is also linked with the Media nodes. Stream segments are named portions of a stream. They are defined by a SegmentDescriptor (see Chapter 3).


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint