2.2.1 Common Header

The common header specifies the size and type of a header. Every header MUST begin with the common header. The common header MUST NOT appear by itself.

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Header Signature
Size

Header Signature (4 bytes):  A predefined value that identifies the specific header. (The value is given in the section that defines each specific header.)

Size (4 bytes):  Size in bytes of the header, plus the size of header-specific variable length data fields if present. Some, but not all, headers have such fields following the header itself, and their size is included in this number. The value MUST be a multiple of 8. Adding the size to the starting offset of a header gives the starting offset of the next header.

All headers defined in section 2.2.2 to section 2.2.6 contain the common header. Unless otherwise specified, "Header Signature" refers to the Header Signature field of the common header that is embedded in the other headers.