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current_next_indicator – A 1-bit field, which when set to '1' indicates that the PSIP_section sent is
currently applicable. When the current_next_indicator is set to '1', then the version_number shall be
that of the currently applicable PSIP_section. When the bit is set to '0', it indicates that the
PSIP_section sent is not yet applicable and shall be the next PSIP_section with the same
section_number, table_id_extension, and table_id to become valid.
section_number – This 8-bit field gives the number of the PSIP_section. The section_number of the
first section in a PSIP table shall be 0x00. The section_number shall be incremented by 1 with
each additional section in PSIP table. The scope of the section_number shall be defined by the
table_id and table_id_extension. That is, for each PSIP table and value of the table_id_extension
field, there is the potential for the full range of section_number values.
last_section_number – This 8-bit field specifies the number of the last section (that is, the section
with the highest section_number) of the PSIP table of which this section is a part. Its scope is
the same as for the section_number field.
protocol_version – An 8-bit unsigned integer field whose function is to allow, in the future, this
table type to carry parameters that may be structured differently than those defined in the
current protocol. At present, the only valid value for protocol_version is zero. Non-zero values
of protocol_version may be used by a future version of this standard to indicate structurally
different tables.
CRC_32 – This is a 32-bit field that contains the CRC value that gives a zero output of the
registers in the decoder defined in ISO/IEC 13818-1, Annex A after processing the entire
private section.
Note that individual PSIP tables defined in this Standard may further constrain the above
fields. But when not further constrained in each table, the above semantics shall apply.
4.2 Extensibility
The PSIP protocol describes a number of tables conveying system information and content guide
data structures. The Standard is designed to be extensible via the following mechanisms:
Reserved fields. Fields in this Standard marked reserved shall be reserved for use either when
revising this Standard, or when another standard is issued that builds upon this one. See
Section 4.4.
Standard table types. As indicated in Table 4.2, table_id values in the range 0xCE-0xDF and
0xE6-0xFE shall be reserved for use either when revising this PSIP Standard, or when
another standard is issued.
Protocol version field. Future substantive structural modifications shall be accommodated by
defining different protocol version numbers. Backwards compatible additions or
modifications may be added without incrementing the protocol version number.
4.3 User Private Ranges
Certain fields in this Standard are defined to include “user private” ranges:
• table_ID values in the range 0x40 through 0xBF
• MGT table_type values in the range 0x0400 through 0x0FFF