[mythtv] Merging cards and inputs, testing help needed

Devin Heitmueller devin.heitmueller at gmail.com
Tue Jan 20 22:15:14 UTC 2015

Hi David,

This is definitely interesting work.  A couple of questions, related
to hybrid cards (i.e. card which have both a DVB and V4L2 input which
cannot be used at the same time).

1.  How do you know a V4L2 device and a DVB device are part of the
same hybrid card?  Do you have some heuristic that you have written
which tells you the device nodes are from the same card?  (I'm asking
because I may be able to help in this area)
2.  How are you replacing the construct for what today are known as
"input groups"?  Today input groups are used to prevent the DVB and
V4L2 device from being used simultaneously.  Presumably you'll need to
provide some similar capability to either indicate within a card that
certain inputs cannot be used simultaneously, or be able to detect
this condition programatically.

If you've already thought through these cases and have a solution, I'm
happy to offer some input (my involvement with the LinuxTV project as
well as having worked for a manufacturer of such tuners suggests I'm
well-versed in such issues).  If you haven't yet considered these
cases, I'm happy to talk through them a bit and explain some of the
challenges and why it may be more complicated than it looks.


Devin J. Heitmueller
AIM: devinheitmueller

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