[mythtv-users] Setting up a Nebula DigiTV DVB-T Card (was: Setting up a DVB Card)

Sun May 8 22:53:49 UTC 2005

On Fri, 06 May 2005 09:23:30 +0100, "Nigel Metheringham"
<Nigel.Metheringham at dev.intechnology.co.uk> said:
> On Thu, 2005-05-05 at 20:45 +0200,
> Geek.Lists.MythTV at MattWynne.fastmail.fm wrote: 
> > Having read your post, I ran all the packages above (only the last three
> > actually updated anything, somehow I'd already got the first two) then
> > did 'make' and 'insmod'[2][3] of dvb-kernel (again!) but I still can't
> > see any 'DVB:' entries in dmesg[1]... which is my success criteria for
> > this step...
> 
> Not quite sure what you mean by this (the make & insmod) bit.
> Have you tried a reboot - this stuff is mainly pulled in by the early
> part of sysinit when it scans the pci bus and pulls in the appropriate
> driver sets

the make and insmod refer to the instructions in the 'Install Drivers'
section of Martin Smith's guide, where he describes how to get the
latest version of 'dvb-kernel' from cvs and build it, then use insmod to
install the modules you've built.

I'm very new to linux, and while I've been really impressed with apt-get
and yum, I'm fairly nervous about building anything and installing it
for fear of screwing the whole system up. Hence my enthusiasm when I saw
you had got things working, apparently without any building of code.

> > Would you mind explaining how you knew which apt-get packages you
> > needed, and how I would go about figuring out which I need for my Nebula
> > card? (according to the linuxtv wiki[4] it's the same as an ATI NXT6000)
> 
> Well the KWorld DVB card is cx88 based:-
>  % /sbin/lspci |grep Conexant
>  02:09.0 Multimedia video controller: Conexant Winfast TV2000 XP (rev 05)
>  02:09.2 Multimedia controller: Conexant: Unknown device 8802 (rev 05)
>  02:0a.0 Multimedia video controller: Conexant Winfast TV2000 XP (rev 05)
>  02:0a.2 Multimedia controller: Conexant: Unknown device 8802 (rev 05)
> 
> I have 2 cards installed, hence the 2 sets of entries

hmmm... my lspci output shows the cards as
00:0f.0 Multimedia video controller: Brooktree Corporation Bt878 Video
Capture (rev 11)
00:0f.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture
(rev 11)

I remember these flashing up when I first installed the card. So it
seems to me that the operating system regognises the card, but I thought
that I then need another layer of drivers on top (the DVB stuff) to
actually get the tv tuner to work - it that not correct?

Martin Smith's guide talks about building/installing the DVB modules so
that the output of 'dmesg' shows something like (his example):
DVB: registering new adapter (TT-Budget/WinTV-NOVA-T  PCI).
tda1004x: Detected Philips TDA10045H.
tda1004x: Detected Philips TDM1316L tuner.
DVB: registering frontend 0:0 (Philips TDA10045H)...

Now try as I might, I cannot get any 'DVB' messages to appear in that
output, and when I try the next step (running dvbscan from the dvb-apps
module on linuxtv.org) I get a message like this:
[root at MediaBox scan]# ./dvbscan dvb-t/uk-CrystalPalace > channels.conf
scanning dvb-t/uk-CrystalPalace
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
main:1958: FATAL: failed to open '/dev/dvb/adapter0/frontend0': 6 No
such device or address

so it seems to me that my problem is installing this 'front-end' DVB
driver which sits on top of the actual device's driver.

> 
> Basically I checked what kernel modules were in the ATrpms repo:-
>  % yum list '*2.6.11-1.14_FC3-kmdl*'
> 
> recognised cx88 as one that was relevant (you can use yum info if you
> don't know what a package is addressing).
> 
> Installing cx88 pulled in several of the other packages as dependencies,
> unfortunately it missed saa7134 which is required, but is not detected,
> so the first boot after did not load the drivers (errors show up
> somewhere related to symbols with names like saa*).   Adding that module
> set and booting fixed this.
> 
> Basically you need to identify exactly which chipset your card is using.
> If that is not one of the standard ones then you are going to have to
> find and build drivers for it.  Remember that modules are kernel
> configuration dependant so you can't pull modules for another kernel
> build into your kernel (unless you enjoy pain and crashes).
> 
> I got the DVB-T cards I use based on 2 criteria:-
>       * They are explicitly supported on the LinuxTV DVB-T pages (and
>         even so I initially got one for trials and then added the other
>         after I was sure it worked).
>       * These are the only cards I found with an accessible aerial in
>         and aerial out connections - so I need no splitters to make the
>         thing work.

This is a good point, might be worth forking out for another more
widely-used card rather than trying forever with this one. I know there
are people out there that have got this working though, which is the
infuriating thing...

see http://www.dtvforum.info/lofiversion/index.php/t14427.html

I notice in here he mentions 'did modprobe nxt600 && dvb-bt8xx to load
these modules'. Not sure what that means yet, but I'm going to read up
and try to get this to work, will post back results here when I make any
progress.

thanks for your help,
Matt