[mythtv-commits] Ticket #9777: Channel scanner stores centre freq instead of offset for DVB-T

[MythTV]

#9777: Channel scanner stores centre freq instead of offset for DVB-T
--------------------------------------------+----------------------------
 Reporter:  david_a <baroque@…>             |          Owner:  danielk
     Type:  Bug Report - General            |         Status:  new
 Priority:  minor                           |      Milestone:  unknown
Component:  MythTV - Channel Scanner        |        Version:  0.24-fixes
 Severity:  medium                          |     Resolution:
 Keywords:  offset frequency                |  Ticket locked:  0
--------------------------------------------+----------------------------

Comment (by david_a <baroque@…>):

 Yes any additional info on a workaround (esp. if it may be quicker than
 manually adjusting and re-scanning the relevant transports) would be worth
 recording in the wiki.

 Another comment worth noting in this discussion (given this particular
 detail may not be obvious unless a person has RF receiver experience) is
 that broadcast tuners use their own automatic fine tuning to lock onto a
 signal once they've been commanded to a frequency which is 'close enough'
 to the real one.  The design of the tuner determines how close is close
 enough, and is the reason why some tuners don't care if the commanded
 frequency might be 125kHz away from the real transmitter frequency, but
 others do. It also follows from this that the value stored in the
 dtv_multiplex table does not have to match exactly the transmitter
 frequency, but needs to be close enough that all models of tuner will
 lock.

 But ultimately the reason for documenting this bug was to provide enough
 detail to allow the code to be modified so that, in any country such as
 Australia which employs DVB-T offsets, the scan would provide a working
 result automatically without requiring the user to resort to external
 utilities or manual adjustments.

-- 
Ticket URL: <http://code.mythtv.org/trac/ticket/9777#comment:5>
MythTV <http://code.mythtv.org/trac>
MythTV Media Center