What is a syntax?
Generally speaking, a syntax specifies the structure of a bitstream: how different parameters, tags, etc., are mapped and laid out on the bitstream. For multiplexing purposes, it is important for the syntax to provide patterns which can be recognized with an extremely high degree of confidence. These patterns are called synchronisation patterns. In addition, an indication of time and of the bit rate of the bitstream may also be provided. Equipped with such elements, a bitstream corresponding to an MPEG-2 syntax is a self contained bitstream on which a receiver can slave itself, in order to acquire that bitstream exactly synchronised with the production of that bitstream. However, time indication and bit rate indication are not mandatory.
