[mythtv-commits] Ticket #4218: DVB-S channel scan does not work on Eutelsat W4 (36.0E)

MythTV mythtv at cvs.mythtv.org
Sat Nov 24 17:00:05 UTC 2007


#4218: DVB-S channel scan does not work on Eutelsat W4 (36.0E)
---------------------------------------+------------------------------------
 Reporter:  Andrew Junev <a-j at a-j.ru>  |       Owner:  danielk
     Type:  defect                     |      Status:  new    
 Priority:  major                      |   Milestone:  0.21   
Component:  channelscan                |     Version:  head   
 Severity:  medium                     |     Mlocked:  0      
---------------------------------------+------------------------------------
 Channel scan does not work when searching for channels on Eutelsat W4
 (36.0E).

 If I choose a "Full Scan (tuned)" in mythtv-setup, put in the transponder
 data, I get that particular transponder scanned. Those channels work Ok
 until I scan a different transponder on this satellite. Whenever a second
 transponder is scanned, all of the channels stop working.

 I noticed there are some transponders that have equal 'transportid' on
 this particular satellite (not sure if it's common for all DVB-S). This
 doesn't seem to be working properly in Myth. In my situation it lead to
 the following:
 During a scan of the first transponder, there are some channels found that
 are (for example) on frequency 12096000 which is a multiplexid 495. When I
 scan a different transponder, mythtv-setup updates dtv_multiplex table and
 multiplexid=495 gets mapped to a new frequency (let's say, 12245000). Of
 course the old channels won't work any longer.

 But that doesn't seem to be the only problem with channel scan. I
 discovered that 'transponder list' that is automatically detected for
 Eutelsat W4 is always the same, although it is far from being complete.
 When I scan only transponders from the transponder list (without adding
 new ones), dtv_multiplex remains unchanged. But 'multiplexid' in the
 'channel' table still gets changed "without any reason" whenever I do a
 new scan. In any case the result is the same: I can't watch any channels
 if I scan more than one transponder.

 This behaviour is stable and repeatable for Eutelsat W4. I first detected
 it with myth 0.20.2 and now it's the same in the SVN of 0.21.

 # /usr/local/bin/mythbackend --version
 Source code version     : 14946
 SVN branch              : trunk
 Library API version     : 0.21.20071123-1
 Network Protocol Version: 36
 Options compiled in:
  linux release using_oss using_alsa using_arts using_backend using_dbox2
 using_dvb using_frontend using_hdhomerun using_iptv using_ivtv
 using_joystick_menu using_lirc using_v4l using_x11 using_xrandr using_xv
 using_xvmc using_xvmcw using_xvmc_vld using_bindings_perl using_opengl
 using_live
 # uname -a
 Linux mythbackend 2.6.22.9-61.fc6 #1 SMP Thu Sep 27 18:48:03 EDT 2007 i686
 i686 i386 GNU/Linux

 I can do additional tests and provide some logs, if needed. I just don't
 know which logs to provide, as it seems that the 'regular' logs does not
 contain anything to trace this problem.

-- 
Ticket URL: <http://svn.mythtv.org/trac/ticket/4218>
MythTV <http://svn.mythtv.org/trac>
MythTV


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