[mythtv-users] Yet another ugly bit of usability surfaces

[f-myth-users at media.mit.edu]

...aaaand, back to my least-favorite form:  Capture Cards.

Here I am, sitting in Capture Cards in my misconfigured R5A22:

    Capture cards
    (New capture card)
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]

There are actually only 4 tuners in the machine right now, 'cause I
stuck a video card back into it.  Booting it caused it to prompt for
the root password and then run mythtv-setup automatically, presumably
because a tuner vanished, although it didn't have the decency to say
so.  Why there are -still- five tuners in the list above is... dubious.

This leads to a really interesting question:  if I boot it headless,
'cause I've added a tuner, does that mean it tries to run mythtv-setup
on its nonexistent X display?  Or does it just err out?  I sorta hope
the latter, so there aren't two copies running (the other being on my
ssh connection) while I'm trying to reconfigure the device numbers.

I'm afraid to try to fix this by running mythtv-setup on the -frontend-,
of course, which is the machine with a single 350 in it, since it's my
understanding that mythtv-setup will wind up setting up only the cards
in the machine it's run on, though talking to the database wherever
that is.  So really, I have to ssh in.  Right?  At least once I replace
the video card with the fifth tuner.

But wait, it gets much better.

I go down to the SECOND tuner in the list, e.g.,

    Capture cards
    (New capture card)
    [ MPEG : /dev/video0 ]
--> [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]

I hit Return.  I go to "Video device" and carefully use the arrow keys
to change it to /dev/video1, knowing as I do (now) that typing in that
field will be thrown away as soon as I select the Finish button.

I hit Return.

-Now- the menu looks like this:

    Capture cards
    (New capture card)
    [ MPEG : /dev/video1 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]

WTF???

This is absolutely repeatable.  I just did it three times in a row,
to prove to myself that I hadn't screwed up and picked off the wrong
entry without noticing.

So apparently the position of the tuners in the list is random?
Meaningless?  Is there any way to keep track of the tuners?  Does
their order matter?  Is whatever is called /dev/video0 used -first-,
assuming I haven't gone into the priorities menu and changed that?
Or is it the top tuner in the list?  Or is it something else?

This matters for a number of reasons having to do with (a) debuggability,
(b) the principle of least surprise, (c) cabling, and (d) sources.

Or, I suppose, I could (and probably should) just flush all my tuners
from the database and start over.  And probably boot.  And powercycle.
And leave the machine off for a minute or two first.  Where's that
chicken I'm supposed to be waving?  Dead of avian flu?  Well, it
was supposed to be dead anyway...

Especially since, if I -now- pick off the second in the list:

    Capture cards
    (New capture card)
    [ MPEG : /dev/video1 ]
--> [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]

...I can change it to /dev/video2 and its order doesn't move around:

    Capture cards
    (New capture card)
    [ MPEG : /dev/video1 ]
    [ MPEG : /dev/video2 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]
    [ MPEG : /dev/video0 ]

...and if I continue to do that (e.g., pick off the third in the list,
then the fourth), I eventually wind up in this situation:

    Capture cards
    (New capture card)
    [ MPEG : /dev/video1 ]
    [ MPEG : /dev/video2 ]
    [ MPEG : /dev/video3 ]
    [ MPEG : /dev/video4 ]
    [ MPEG : /dev/video0 ]

...and now there's this interesting thing:  Because there's no fifth
tuner in the machine, the /dev/video4 entry WON'T LET ME CHANGE THE
DEFAULT INPUT from "Composite 0", though it won't tell me why---the
field just magically won't accept a new setting from the arrow keys.
At least, I -assume- the lack of a fifth tuner, when it was originally
configured to have one, is why this behavior is happening; I can only
guess.

So why's the entry there?  How come I could change its device number,
but not its default input?  If I can't actually -do- anything to the
damned thing, and in fact the tuner isn't even in the machine, why am
I presented with the tuner?  And if the idea is to enable me to change
it and -then- stick in the tuner, why is it preventing me from changing
the default input?

This whole menu needs a complete re-think.

Yucko.

P.S.  If I change an entry from /dev/video0 to /dev/video1, the input
magically changes from Tuner 0 to Composite 0.  That's pretty annoying;
now I have to change it back.  And then I'm left wondering, "is there
some sort of leftover Tuner 0 on /dev/video0?"  I don't even know if
that's a well-formed question; probably not.  It just looks like any
change of devnum resets the default input in the UI.  Why?  Who knows!
But it sure means there's a hidden ordering to which fields have to be
changed when...