[mythtv-users] feedback for feature request: ability to define input connections as inactive

[Joe Harvell]

I recently filed a bug report (http://svn.mythtv.org/trac/ticket/3093)
having to do with input connections with no video sources.  The bug is
that the frontend crashes when you try to access the program guide if
there are no input connections associated to video sources.  The
response I got was that the frontend should not crash, but instead, the
program guide should show nothing.  I argue that as long as you have
channels defined you should be able to look in the program guide and
make schedules.

Another problem associated with input connections is that if you have a
capture card defined, but none of that specific capture card's input
connections is associated with a video source, the backend complains
that init of that card failed.  Then later, the backend crashes if you
look at "Tuner Status" from "System Status" in mythfrontend.  I think
this is a big problem when you have a capture card whose inputs are all
temporarily unusable (e.g., disconnected).  You have to delete the
capture card and restart the backend if you don't want the scheduler to
try to use it to make recordings.

An easy way to address both above problems is to allow input connections
to be put in an "inactive" state.  Inactive in this context means that
they are not eligible for watching LiveTV or making recordings.  This
inactive state is what you would put the input connections in when
nothing is connected to them.  This can be implemented by adding a
boolean column to table cardinput with a default value of TRUE.  It
should not be allowed to assign active=TRUE and have no video source.

Currently, you can't even define an input connection without assigning a
video source to it.  Table cardinput does not get populated at all if
you don't assign a video source.  Similarly, rows are deleted from
cardinput if you delete the video source from them.  This means the
system throws away all the configuration data associated with the input
connection if you want to temporarily delete the association to the
video source.  This would no longer be necessary if the active/inactive
flag were there to tell you whether to use the input connection or not.

The reason the program guide doesn't show anything if you have no card
inputs with video sources is because the program guide needs to know
which channels have video sources.  But it shouldn't matter whether they
are currently usable (e.g. physically connected) to be able to look at
the listings.  If we no longer make input connections existence
dependent on their associated video sources, the system has all the data
it needs to be able to build the program guide and make schedules.

It seems like most of the code that would need to change would be
limited to code specifically involved in selecting input connections for
Live TV and making recordings.

I would be willing to implement and test this.


Comments?
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Joe Harvell