Mailing List Archive: Problem with change inputs on TV Tuner card

I tried typing "C" (per keys.txt to change inputs) and have lost video as a
result - the video is all black. Typing C again brings up the popup "Composite
0" and I can see the popups when I change channels. Video card is a PVR-250.

I've tried stopping and restarting mythbackend and restarting Linux as well as
reconfiguring (using setup) from scratch. None of this helps. mplayer also
can't play files I save using "cat /dev/video0 > sample.mpg".

When I turn off power and then power on and boot, I can capture and play video
with mplayer. Once I start MythTV I have the same black video display (except
for popups). I shut down the backend. Files that I now save with cat
/dev/video0 play back black in mplayer.

I don't see any error messages in the mythbackend or mythfrontend terminal
windows.

Any suggestions as to what I should try? Is there debug output I can capture
that will help?

Thanks,
Vince

PS: I know typing "C" was dumb since I don't have any other video inputs, but I
am having sound sync problems and was just trying things to see what they did -
hoping I would stumble across a solution to the sound sync problem (couldn't
find a solution in the user's archive.)

I think there may be a MythTV problem (bug?) here.

When I start mythbackend, it shows what I believe to be 10 possible video
inputs:
Composite 0 to 4
Tuner 0
S-Video 0 to 3

I only have input on Tuner 0.

When I type "C" to change the input on the TV tuner card, I see a popup that
says "Composite 0". I wait for this popup to go away and try "C" over and over
again (I tried this a total of 12 times). The popup ALWAYS show "Composite 0".
It never goes back to "Tuner 0".

As is reasonable to expect, MythTV has changed setting on the PVR250. Using
test_ioctl, the width, VIDIOC_G_INPUT, and VIDIOC_G_FREQUENCY were changed (720
to 480, 4 to 0, and 0 to 2804 respectively). When I change these values back
using test_ioctl, I can record again using cat and play using mplayer but not
with MythTV.

The mythconverg database contains "Composite 0" both in the defaultinput column
in the capturecard table and in the inputname column in the cardinput table.

When I go back to the myth setup program and set the Capture Card's Default
Input to "Tuner 0", the TV works again.

I'm not happily fully setup yet, but am making progress.

Thanks to Isaac and the rest of the MythTV team for all their great work!

Vince