Summary

Optional Additional Supplemental Enhancement Information which can be added to an H.263 bitstream to provide backward-compatible enhancements, including:

•            Indication of use of a specific fixed-point IDCT.

•            Picture Messages, including the message types of:

-    Arbitrary Binary Data;

-    Text (Arbitrary, Copyright, Caption, Video Description, or Uniform Resource Identifier);

-    Picture Header Repetition (Current, Previous, Next with Reliable Temporal Reference, or Next with Unreliable Temporal Reference);

-    Interlaced Field Indications (Top or Bottom); and

-    Spare Reference Picture Identification.