[mythtv-users] Problems with DVB-C Streams: Audio and Video Playback

[Rho]

Hello

I've upgraded my MythTV system (running SVN trunk, revision 15947) with
a DVB-C card, and after some minor installation problems (mainly kernel
related), I was finally able to tune channels and play with mplayer and
record streams.

I quickly started MythTV and imported my channels.conf, switched on the
TV, but the picture/audio is getting quite a hiccup after a few seconds
- I've got glitches in the MPEG stream, audio dropping out from now and
then ... the log shows a lot of "TeletextDecoder: No Teletext Viewer
defined!", which i deem not problematic, a few "VBI: Unknown descriptor:
<xxx>" and later on a few messages coming from ffmpeg like "mpeg2video"
"MPEG motion vector out of boundary", "slice mismatch" and (exemplary)
"concealing 387 DC, 387 AC, 387 MV errors".


I've spent a few hours trying to find out what's going wrong, with not
much luck until now.

As a resumee:

- created channels.conf with w_scan [1]

- tuned channels using czap and the channels.conf created above

- played dvb-stream using mplayer with absolutely no problems, even HD
streams

- made a few futile efforts scanning for channels in MythTV and
eventually imported channels.conf created above

- checked database for (hopefully) correct entries, see extract from
channels.conf [2] and matching entry in the DB [3]

- switched playback using libmpeg and ffmpeg, with different deint's

everything to no avail ... is there anybody having similar problems? Any
hints on where I should have a closer look?


Best regards

Rho



[1] http://wirbel.htpc-forum.de/w_scan/index2.html

[2] channels.conf:
SF1(GAG):386000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_256:1011:1012:1010

[3] mythconverg DB entries for channel SF1:

<mythconverg>
    <!--
   SELECT * FROM channel JOIN dtv_multiplex ON (channel.mplexid =
   dtv_multiplex.mplexid ) WHERE callsign = "SF1"
   -->
      <channel>
          <chanid>5010</chanid>
          <channum>1010</channum>
          <sourceid>4</sourceid>
          <callsign>SF1</callsign>
          <name>SF1</name>
          <icon></icon>
          <videofilters></videofilters>
          <xmltvid></xmltvid>
          <recpriority>0</recpriority>
          <contrast>32768</contrast>
          <brightness>32768</brightness>
          <colour>32768</colour>
          <hue>32768</hue>
          <tvformat>Default</tvformat>
          <commfree>0</commfree>
          <visible>1</visible>
          <outputfilters></outputfilters>
          <useonairguide>0</useonairguide>
          <mplexid>32</mplexid>
          <serviceid>1010</serviceid>
          <tmoffset>0</tmoffset>
          <atsc_major_chan>0</atsc_major_chan>
          <atsc_minor_chan>0</atsc_minor_chan>
          <last_record>0000-00-00 00:00:00</last_record>
          <default_authority></default_authority>
          <commmethod>-1</commmethod>
          <mplexid>32</mplexid>
          <sourceid>4</sourceid>
          <transportid>1</transportid>
          <networkid>1</networkid>
          <frequency>386000000</frequency>
          <inversion>a</inversion>
          <symbolrate>6900000</symbolrate>
          <fec>none</fec>
          <modulation>qam_256</modulation>
          <lp_code_rate>auto</lp_code_rate>
          <visible>0</visible>
          <sistandard>dvb</sistandard>
          <serviceversion>20</serviceversion>
          <updatetimestamp>2008-02-13 21:59:44</updatetimestamp>
      </channel>
</mythconverg>