This contains information related to one or more "group-of-pictures"
Byte# Data Details
===================================================================
1-4 Sequence header In Hex 000001B3
code
12 bits Horizontal size In pixels
12 bits Vertical size In pixels
4 bits Pel aspect ratio See below
18 bits Picture rate See below
1 bit Marker bit Always 1
10 bits VBV buffer size Minimum buffer needed to decode this
sequence of pictures; in 16KB units
1 bit Constrained
parameter flag
1 bit Load intra 0: false; 1: true (matrix follows)
quantizer matrix
64 bytes Intra quantizer Optional
matrix
1 bit Load nonintra 0: false; 1: true (matrix follows)
quantizer matrix
64 bytes Nonintra quantizer Optional
matrix
- Squence extension Optional
Data
- User data Optional application-dependent data
===================================================================
Aspect raios are defined by a code which represents the height and
width of the Video image.
Picture rates are also defined by a code that represents the number
of pictures that may be displayed each second.
Each group of pictures has a header that contains one "I picture"
and zero or more B and P pictures. The header is concerned with
the time synchronisation for the first picture in this group, and
the closeness of the previous group to this one.