[mythtv-users] How does test_ioctl relate to mythtvsetup?

Jarod C. Wilson jcw at wilsonet.com
Fri Feb 13 20:57:38 EST 2004

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On Friday 13 February 2004 04:47, Mark Crutch wrote:
> After some six months of trying various distributions, HOWTOs and web
> sites, I've finally made some significant progress on the road to MythTV
> happiness. But I still have one significant hurdle to overcome. My
> configuration is:-
> * Epia M10K motherboard, using the on-board video out with the VIA binary
> drivers * PVR350 - Only being used for capture (until the output can also
> handle MythVideo better) * Stock RH9 download kernel (2.4.20-8 - I pretty
> much have to stick with this for the VIA drivers) * Alsa using the SPDIF
> output on the motherboard and the via82xx driver * MythTV suite (0.14)
> installed from atrpms using apt, roughly following Jarod's guide
> I can capture video using "cat /dev/video3 > test.mpg". To get a real
> image, rather than static, I have to set up various parameters using
> test_ioctl as follows pretty much as per the PAL settings in Jarod's guide.
> I've had to make some minor changes (input=2, -p 4, running -u 0xff last)
> to get everything recording okay.
> After doing the test_ioctl stuff, I can tune to a channel using ptune.pl
> from the ivtv code, and can capture audio and video as expected. Playing it
> back with "mplayer -ao alsa9:spdif test.mpg" playes fine.
> Now here's the problem. When I try to watch live TV in MythTV, I can get a
> picture (but no sound), but it seems to be locked on the channel I used for
> the test above. I.e. I can't change channels.
> Looking through the archives, it seems that MythTV should handle all the
> stuff that I'm currently doing with test_ioctl and ptune.pl, but if I
> reboot and launch MythTV without setting any of these, I get nothing but a
> black screen.
> Obviously I've set something wrongly in mythtvsetup, but I can't find any
> reference that tells me how the test_ioctl parameters correspond to the
> mythtvsetup options. Jarod's guide simply says "MythTV now controls some
> (all?) of these functions internally, so be sure to set similar values when
> we get to the MythTV setup portion" but doesn't go into any more detail.

No, I don't go into detail there, because I refer people to this page, which 
pretty much covers it:


> So, for example, does setting "PAL" as my video format automatically
> achieve the same as "test_ioctl -u 0xff"?


> Or maybe the "-p 4" part?

No, that is the input. "-p 4" corresponds (usually) to the tuner input.

> Or
> both? Or am I looking in completely the wrong place anyway? Which parts (if
> any) do I need to run _before_ launching mythbackend, and which are taken
> care of by the parameters in mythtvsetup?

Pretty much everything will be taken care of by mythtvsetup and your recording 
profiles (set those in mythfrontend). You *might* have to set the input=2 
thing, I'm not really sure. All four of my ivtv cards just work. ;-)

> Any help would be greatly appreciated, because I'd hate to have come so
> close to finally fall at the last hurdle.

You probably aren't too far off. At the very least, it sounds like you have 
the wrong default input set up in mythtvsetup, so start there.

> BTW, this isn't intended as a criticism of Jarod's guide at all - it's an
> awesome resource and my problem is probably down to the places where I had
> to deviate from it.

I'm a big boy. I can take criticism. And I gladly welcome suggestions for 
improvement. =)

- -- 
Jarod C. Wilson, RHCE

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