[mythtv] Re: [mythtv-commits] mythtv commit: r7133 by danielk

[Allan Stirling]

Daniel Kristjansson wrote:
> On Thu, 2005-08-25 at 22:16 +0100, Allan Stirling wrote:
> 
>>2005-08-25 22:09:05.942 PSIP packet failed CRC check. pid(0x104) type(0x2)
> 
> 
> Ok, I'm ignoring your second problem for now. Attached is a patch
> that will print out the PMT that is failing the CRC check. If it
> looks ok then maybe we can just pretend that it is OK based on 
> some option or hardware detection rutine.
> 
> If it the PMT looks ok to you, you can try skipping the CRC check
> altogether when (TableID::PMT == psip->TableID()). See if that lets
> you tune. The CRC check should hardly ever fail for the PMT table
> unless there is a problem at the transmitter. There are layers of
> ECC protection before the CRC, and that table is sent so infrequently
> as compared to say EIT tables, that you shouldn't see any CRC failures
> on it by chance.
> 
> -- Daniel
> 
> 
> ------------------------------------------------------------------------
> 
> Index: libs/libmythtv/mpeg/mpegstreamdata.cpp
> ===================================================================
> --- libs/libmythtv/mpeg/mpegstreamdata.cpp	(revision 7135)
> +++ libs/libmythtv/mpeg/mpegstreamdata.cpp	(working copy)
> @@ -357,6 +357,14 @@
>          VERBOSE(VB_RECORD, QString("PSIP packet failed CRC check. "
>                                     "pid(0x%1) type(0x%2)")
>                  .arg(tspacket->PID(),0,16).arg(psip->TableID(),0,16));
> +
> +        if (TableID::PMT == psip->TableID() &&
> +            tspacket->PID() == _pid_pmt_single_program)
> +        {
> +            VERBOSE(VB_RECORD, "Garbled PMT looks like....\n"
> +                    <<ProgramMapTable(*psip).toString());
> +        }
> +
>          HT_RETURN(true);
>      }
>  
> 

If I manually override the CRC check, the PMT seems OK. However, tuning 
still fails - Only with this one card, again. I'm trying to have a look 
at the raw data with dvbsnoop now.

2005-08-26 22:30:54.654 PSIP packet failed CRC check. pid(0x104) type(0x2)
2005-08-26 22:30:54.654 Garbled PMT looks like....
Program Map Table ver(24) pid(0x104) pnum(51001)
      Unknown Descriptor (0xb) length(2)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x10) length(6)

  Stream #0 pid(0x909) type(video-mp2  0x2)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x2) length(3)
      Unknown Descriptor (0x6) length(1)
      Stream Identifier Descriptor (0x52) length(1)
  Stream #1 pid(0x90a) type(audio-mp2-layer[1,2,3]  0x4)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x3) length(1)
      ISO-639 Language Descriptor (0xa) length(4)
      Stream Identifier Descriptor (0x52) length(1)
  Stream #2 pid(0x90b) type(audio-mp2-layer[1,2,3]  0x4)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x3) length(1)
      ISO-639 Language Descriptor (0xa) length(4)
      Stream Identifier Descriptor (0x52) length(1)
  Stream #3 pid(0x90c) type(audio-mp2-layer[1,2,3]  0x4)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x3) length(1)
      ISO-639 Language Descriptor (0xa) length(4)
      Stream Identifier Descriptor (0x52) length(1)
  Stream #4 pid(0x90d) type(audio-mp2-layer[1,2,3]  0x4)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x3) length(1)
      ISO-639 Language Descriptor (0xa) length(4)
      Stream Identifier Descriptor (0x52) length(1)
  Stream #5 pid(0x90e) type(audio-mp2-layer[1,2,3]  0x4)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x3) length(1)
      ISO-639 Language Descriptor (0xa) length(4)
      Stream Identifier Descriptor (0x52) length(1)
  Stream #6 pid(0x90f) type(audio-mp2-layer[1,2,3]  0x4)
      Unknown Descriptor (0xe) length(3)
      Unknown Descriptor (0x3) length(1)
      ISO-639 Language Descriptor (0xa) length(4)
      Stream Identifier Descriptor (0x52) length(1)

2005-08-26 22:30:54.774 PSIP packet failed CRC check. pid(0x104) type(0x2)

Cheers,

Allan.