[mythtv-users] Fine Tuning Question

[Ray Olszewski]

At 04:40 PM 5/29/2003 -0400, Jeff Waters wrote:
[...]
>Hmmm I'm going to sound really dumb here,.. but where do you specify
>your tuner type? (I've no clue what the tv wonder uses) And... where do
>I use bttv?

bttv is a kernel module that provides the interface to many v4l 
(video4linux) vidcap cards ... the ones that use the bt848 or bt878 chips. 
If you run "lsmod", it should show that bttv is running. You'll also see an 
i2c module (I forget the excact identifier) and a tuner module (which 
handles channel changing).

I don't use Mandrake myself, so I'm not certain where you specify module 
options. The usual place is /etc/modules.conf . bttv autoprobes cards and 
tries to figure out the card type and the tuner type on its own. In your 
case, it *may* be guessing the wrong tuner type (possibly guessing type 2 
when you have type 17, but here I'm really going out on a limb, based not 
on personal knowledge but imperfect memory of other messages I've seen here).

Anyway, to see what you have, check the dmesg buffer right after you 
boot/init the system (use the command "dmesg" to do this), or see if 
Mandrake, like may distros, copies the initial contents of this buffer to a 
file in /var/log . Either way, look for lines with "bttv" in the to see 
what you are getting.

There is no man page for bttv, since it is a kernel module. Look in the 
kernel documentation (that comes with kernel source) for a bttv 
subdirectory, to see the docs for this module.

Before xawtv started scanning for channels, you had to tell it what 
frequency set to use. Some USA cable operators use us-cable, others 
us-cable-hrc, and there's no way to know unless they tell you (or you try 
both and then use the one that works better). The two frequency sets are 
somewhat similar, so if you guessed wrong, you might be seeing what you 
describe.

So ... to sum it up ... your problem still may be wrong tuner type or wrong 
frequency set. You haven't told us enough to tell. But with this additional 
information, you may be able to track down the needed details.

>To be honest I bought the card, slapped it in and Mandrake said hey
>there is a new card and I started up xawtv and it scanned for channels
>and I was up and working... of course all the channels were off by 1 and
>fuzzy so I messed around with it till I figured out it was +111 off in
>the fine tuning. So I've been adjusting it like that since I bought it a
>year ago. I've used (here in Ohio) Time Warner and now Wide Open West
>cable.
>I have never messed with Bttv... although from your response it seems I
>should have.
>I guess I need to read the man page on bttv then.