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

[Mark Crutch]

Previously, Jarod C. Wilson wrote:
> On Friday 13 February 2004 04:47, Mark Crutch wrote:
> > 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:
> 
> http://www.mythtv.org/docs/mythtv-HOWTO-9.html


I had checked that page but in the section for TV capture card configuration it just says: "Choose the appropriate settings for your particular tuner". Again, no indication of what is "appropriate" for a particular combination of test_ioctl parameters.

I'm not suggesting that either guide should necessarily go into detail about every option - obviously there are so many different configurations out there it would be impractical to do so (not to mention the phenomenal rate of development making it a bit of a moving target). But the context help in mythtvsetup typically always seems to be missing for those options that are perhaps the least obvious.

Not wanting to fan the flames of the mailing list vs. forum/whatever argument, but I think that a Wiki would be an ideal solution for helping to document the setup/config screens. Each option could be expounded on in much more detail than is available in the context help, and anyone would be able to add their own comments if they had to enter a non-obvious setting to get something to work.


> > So, for example, does setting "PAL" as my video format automatically
> > achieve the same as "test_ioctl -u 0xff"?
> 
> Yes.
> 
> > Or maybe the "-p 4" part?
> 
> No, that is the input. "-p 4" corresponds (usually) to the tuner input.

Yep, typically I realised this just afetr I clicked the "Send" button. As it happens, I did have to use "-p 4" which translated to "Tuner0", but I notice in the ivtv documentation that some people have to use other values for the -p option. Apart from the fact that "Tuner0" is the fifth item in the list, and that the -p options are zero-based, there is no real indication that the two are necessarily related. Perhaps just a minor addition to your guide such as this would help:-

"MythTV now controls some (all?) of these functions internally, so be sure to set similar values when we get to the MythTV setup portion (e.g. '-p 4' corresponds to the fifth input, 'Tuner0', in the setup program)"

This would give the clue that a different value for -p corresponds to a different input in the setup program.

> 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. ;-)

As it happens, my settings were correct (by luck more than judgement). I did have to set the input=2, after which I started getting static rather than a black screen. I'm not 100% sure that the two events are related, but I've set it in my rc.local just in case ;)

Once I'd got static, it was obvious that my tuner settings needed to be changed. This took me quite a while, and a lot of trial and error to sort out. Eventually I discovered that what mythtvsetup refers to as "Freq ID" (or similar - the top of the second page of the channel editor) is what ptune.pl refers to as the "Channel" (set with the -c option).

To me it was not obvious that a large entry box labelled "Freq ID" actually required me to enter the numeric value for my channel, so of course I'd been entering this value into the previous screen. Again, this is somewhere that a Wiki could expound on what each paramter actually means. At the very least, adding some context help to "Freq ID" would clarify things.


Anyway, I now have MythTV up and running, and am incredibly impressed with it. So far I've suffered (once) from the loss of sound using the PVRx50 that others seem to have experienced, so I'm not quite ready to throw out the VCR just yet. But on the whole it's an incredible system and I'm extremely grateful to all of the developers for the work they've put into it.

Mark