PMT

Description
The PMT ( Program Map Table ) gives information about the elements of the service. The value of the PMT PID which can be found in the PAT is free to choose within the 32-8190 range. The pids 0 - 31 & 8191 are reserved. It is permissible to map the PMT of different services in the transport stream on the same PID. In practice this is rare, each service often has its own PMT PID.
TR 101 290
  • The repetition rate must be less than 0.5 seconds.
  • The time between receiving the last byte of the section and the first byte of the next section should be at least 25 ms.
  • The Scrambling Control must have the binary value '00 ' ( umscrambled )
  • Descriptors
    The following descriptors may appear in the PMT :
  • VBI_data_descriptor
  • VBI_teletext_descriptor
  • mosaic_descriptor
  • stream_identifier_descriptor
  • teletext_descriptor
  • subtitling_descriptor
  • private_data_specifier_descriptor
  • service_move_descriptor
  • scrambling_descriptor
  • data_broadcast_id_descriptor
  • AC-3_descriptor
  • ancillary_data_descriptor
  • application_signalling_descriptor
  • adaptation_field_data_descriptor
  • related_content_descriptor
  • ECM_repetition_rate_descriptor
  • enhanced_AC-3_descriptor
  • DTS_descriptor
  • AAC_data_descriptor
  • extension_descriptor
  • user defined

  • name bits description
    PMT
    Table ID 8 Indicates to which table this section belongs, in this case PMT (0x02)
    section_syntax_indicator 1 Indicates whether a sub-table structure including CRC check is used.
    0 1 always binary value '0'
    Reserved 2 always binary value '11'
    Section length 12 The length of the section in bytes. This length starts immediately after this field and includes the CRC.
    Program number 16 Indicates the service of this PMT.
    reserved 2 always binary value '11'
    version_number 5 value between 0 to 31.
    A higher value indicates that the information has changed.
    current_next_indicator 1 This is to indicate whether a section is 'valid now' or 'valid in future'
    section_number 8 Value between 0x00 - 0xFF. Used to indicate the sections of a table. Up to 256 sections
    last_section_number 8 The number of the last section, so the receiver know when the table is completely received.
    reserved 3 always binary value '111'
    PCR PID 13 This 13-bit field indicates the PID of the TS packets in which the PCR is found for this service. If the service does not contain a PCR the value must be 0x1FFF
    reserved 4 always binary value '1111'
    Program info lengte 12 The length of the program descriptors. The first two bits must be 00. The remaining 10 bits give the length of the descriptors.
    Program Descriptor Loop
    Program Loop
    stream type 8 Indicates the type of the ES stream
    reserved 3 always binary value '111'
    Elementary pid 13 This 13-bit field indicates the PID of the Elementary stream
    reserved 4 always binary value '1111'
    ES info length 12 The length of the Elementary Stream Descriptors loop. The first two bits must be 00. The remaining 10 bits give the length of the descriptors.
    Elementary Stream descriptors loop
    CRC_32 32 Cyclic redundancy check