Measurement Functions
2–8
MTD200 MPEG Test Decoder User Manual
PMT_error (1st priority)
The PMT (Program Map Table) is a table for detailed program descriptions
referenced in the PAT. As essential information for the MPEG-2 decoder, it
contains the PIDs of all packets of the individual TV, audio, and data streams
(elementary-stream PIDs) as well as the PIDs of packets serving for the
transmission of PCR values associated with the program. Like the PAT, the PMT
is of key importance for decoding TV and audio programs. If PMT is not
available or contains an error, the MPEG-2 decoder will not be able to select and
decode a program from the transport stream multiplex.
The syntactic structure of a PMT is defined in MPEG-2 systems (ISO/IEC
13818-1). In contrast to the PAT, the PIDs of the individual PMTs are variable;
MPEG-2 permits values ranging from 0x0010 to 0x1 FFE (compare to DVB
ETS 300468: 0x0020 to 0x1 FFE). The table may be divided into a maximum of
256 sections with one section for each program. The table index (table_id) of
each section must be 0x02.
In the DVB Measurement Guidelines (ETR290), the preconditions for a
PMT_Error message are set as follows (abbreviated designations in parentheses
are as text displayed in the monitoring report):
PMT ERROR is signaled if
PMT table index does not equal 0x02 (TABLE ID)
or
PMT is transmitted in encrypted form (SCRAMBLED)
or
PMT is not transmitted at least every 0.5 second (UPPER DISTANCE)
An error of this type (cumulative message) is indicated by the LED labeled PMT
lighting (line of LEDs at front panel). Detailed information on the type of PMT
error as defined in the above table can be obtained from the monitoring report.
Summary of Contents for MTD200
Page 1: ...User Manual MTD200 MPEG Test Decoder 070 9951 00...
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Page 29: ...Introduction to Digital TV Transmission Technique 1 14 MTD200 MPEG Test Decoder User Manual...
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Page 167: ...Remote Control 5 70 MTD200 MPEG Test Decoder User Manual...
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Page 174: ...Maintenance and Checking 6 6 MTD200 MPEG Test Decoder User Manual...
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Page 204: ...Glossary Glossary 10 MTD200 MPEG Test Decoder User Manual...
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