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I have a program that's analyzing the PCR value of several ts streams coming from satellite source. It all looks fine for days but sometimes after let say 17 days the program notice a PCR rewind (not a wraparound) for a certain ts stream.

The program has a build in future to detect a normal PCR value wraparound with values mentioned in the following post: Maximum value of PCR

A wrap around occurs each +-26h30m. Than the value resets itself to 0. I see in my analyzing program that the PCR value suddenly jumps from 26:15:34 to a 24:25:58 value. For the first value the PCR wraparound should have taken place 15 minutes later but instead it got a new PCR value and the PCR wraparound took place +- 2h5m later. I can confirm that the new PCR value (re winded value) is now the active/correct PCR value of that certain ts stream.

Does anyone recognize or can explain this kind of behavior?

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Gregory
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1 Answers1

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The stream might have switched to a different encoder. If this is an expected discontinuity it should be signaled using the discontinuity_indicator in the adaptation field.

aergistal
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  • I added the indicator you mentioned to the analyzing output of the program and had another hit on a pcr abrupt change. previous_pcr=26:09:02.433, pcr=1:28:54.443,discontinuity_indicator=0. Maybe to signaling of this indicator is not done correctly by the distributor? – Gregory Sep 29 '16 at 13:47
  • @Gregory If the PCR gap is more than 100 ms and there's no discontinuity indicator then it's a PCR error. – aergistal Sep 29 '16 at 13:56