[mythtv] Problem with HDHR and QAM

Scott list-mythtv at bluecamel.eml.cc
Tue Sep 18 17:14:23 UTC 2007

I posted this to mythtv-users this AM but the more I look over it I
think it may be a bug somewhere. I'm not sure if the issue is the
QAM stream (PMT/PAT missing or bad?), the HDHR, or with the mythtv

Any suggestions on how to narrow down the problem and gather more data
would be great. Work arounds and fixes are even better. :)

I have an HDHR running the current 20070914 firmware and am using MythTV
fixes mythtv-0.20.2_p14498 on gentoo. I'm trying to setup QAM for TWC in
Raleigh/Durham for the first time.

My problem is I see all the channels I want except for two channels on
the same freuency. The problem is with channel 113.1 WTVD-DT ABC and
channel 113.4 WRAZ-DT NBC. These two channels show up fine in the HDHR
scan but not when MythTV does a scan. I have no problems with MythTV
scanning and tuning other QAM channels.

When I do a scan with the HDHR I get the following for 113:

   SCANNING: 729000000 (us-cable:113, us-irc:113)
   LOCK: qam256 (ss=88 snq=88 seq=100)
   PROGRAM: 1: 0.0
   PROGRAM: 2: 0.0
   PROGRAM: 3: 0.0
   PROGRAM: 4: 0.0
   PROGRAM: 5: 0.0
   PROGRAM: 6: 0.0

When I scan from MythTV this frequency returns a timeout - "no tables"
error. From the mythtv-setup debug output:

   2007-09-18 08:54:09.242 SIScan(1010317c/1): \
   Transport Scan Item 'QAM-256 Channel 113' #113
      mplexid(-1) standard(atsc) sourceid(1)
      UseTimer(0) scanning(0)
      timeoutTune(1000 msec)
      frequency(729000000) modulation(5)
      offset[0..2]: 0 0 0

If I use hdhomerun_config I can tune to both of these channels and
get good video and audio through vlc. Mythtv isn't picking them
up in the scan though.

Does anyone have any suggestion on how to get MythTV to pick up
these two QAM channels?

Here's the debug output after I've tuned the HDHR to the 113.1:

   tun: ch=qam256:729000000 lock=qam256 ss=87 snq=87 seq=100
   dev: resync=0 overflow=0
   ts:  bps=38809216 ut=92 te=0 miss=0 crc=0
   flt: bps=11027328
   net: pps=0 buferr=0 neterr=0 stop=0

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