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Remultiplexing Issues

Remultiplexing — taking an existing transport stream as input and re-encapsulating it into a new TS — can introduce problems that are difficult to diagnose with ETSI TR 101 290 errors alone.

Encapsulation of a stream that already has errors

When a remultiplexer receives a TS that contains CCE errors and re-encapsulates it, it creates new TS packets with fresh, correct continuity counters. The result: a stream that passes CC checking cleanly — but is missing content.

Encapsulation of a "broken" stream — errors are hidden, content is still missing

Subscriber devices will experience service problems (image glitches, missing audio segments, incomplete PSI/SI) with no ETSI TR 101 290 errors to indicate why.

Diagnosis: Connect TS Analyzer directly to the input of the remultiplexer (i.e., the source signal before remultiplexing) and check for CCE errors there. If errors are present at the input but absent at the output, the remultiplexer is masking errors by re-packaging them. Fix the source — not the remultiplexer.

A faulty remultiplexer producing random content

In rare but real cases, a malfunctioning remultiplexer (or one that fails to validate its input) may pack a stream consisting essentially of random bytes. This produces:

  • An enormous and constantly growing number of unique PIDs visible in the statistics screen
  • Random PSI/SI sections appearing and disappearing
  • An avalanche of Unreferenced_PID errors (3.4) as random PID values accumulate
  • Absence of PAT (1.3a) or wildly inconsistent PMT (1.5a) errors
  • Receiving devices attempting to process "noise" as valid TS, leading to high CPU load and freezing

Diagnosis: The combination of rapidly accumulating unreferenced PIDs + absent PAT + many PMT errors strongly suggests a remultiplexer fault. Feed the remultiplexer's source signal into TS Analyzer and verify it is a valid TS with no structural errors. If the source is clean but the remultiplexer output is not, the remultiplexer is the problem.

Remultiplexer reconfiguration artifacts

After reconfiguring a remultiplexer (adding or removing services, changing PIDs), brief transient errors are normal. Allow a few seconds for the output to stabilize before drawing conclusions. Transient CCE errors, missing PAT sections, and temporarily absent PMTs during this window are expected and do not indicate a fault.

If errors persist beyond a few seconds after reconfiguration, investigate:

  1. Whether the new configuration is valid (no PID conflicts, PCR PID correctly assigned).
  2. Whether PCR restamping is enabled if service bitrates have changed (not all remultiplexers support this).
  3. Whether the PSI/SI generator has been updated to reflect the new service composition.

PCR restamping

When a remultiplexer changes the timing or bitrate of a service, the PCR values in the original stream become incorrect for the new bitrate. A remultiplexer that supports PCR restamping corrects the PCR values to match the new stream timing. Without restamping, PCR_accuracy_error (2.4) will be permanently active for the affected services and decoder synchronization may degrade over time.

Enable PCR restamping on the remultiplexer wherever the feature is available.