DigitalNow's DNTV LP on Linux

Introduction

So you've just got yourself one or maybe two DVB-T cards from DigitalNow. Well done. But this card is the DNTV low profile, a real beaut card very well suited to the HTPC or desktop that you're about to plug it in to. All well and good. However, you're a Linux dude you want a trouble free, hassle free howto on what you need to get it working. Well, that's what I'm about to show you how.

The reason I chose this card is because it doesn't use the BT878 driver, but the Conexant Reference Design Drivers. This just works!!! Unlike BT878 based cards. You've been warned...

Firstly, I run Gentoo Linux so what I show you will have to be carried over to whatever flavour of Linux you've chosen. What I'll be explaining should pretty much be the same across all Linux distributions so you'll be up and running in no time.

The Kernel

I'm running Con Kolivas patchset for my kernel but the things we'll be switching on will be available in all 2.6 kernels. I'm not going to show you how to build your kernel, just the options that you need.

Set the following in the following order:

Device Drivers -->
    Multimedia devices -->
        Video For Linux = M
        Digital Video Broadcasting Devices -->
            DVB For Linux = Y
            DVB Core Support = M
        Video For Linux -->
            Conexant 2388x (bt878 successor) support = M
            DVB/ATSC Support for cx2388x based TV cards = M
            Build all supported frontends for cx2388x based TV cards = Y

If you have a second card, I found it impossible to get it recognised except by a little bit of kernel hacking. All that's needed is a change to one line. From the root of your kernel source, edit drivers/media/video/cx88/cx88-cards.c and at around line 1442 (or search for 0xa8a6) you should see the following:

.subvendor = 0x17de,
.subdevice = 0xa8a6,
.card      = CX88_BOARD_DNTV_LIVE_DVB_T,

Change the last line to look like the following:

.subvendor = 0x17de,
.subdevice = 0xa8a6,
.card      = CX88_BOARD_CONEXANT_DVB_T1,

Build your kernel as normal, install your modules, install your kernel. Don't reboot just yet as we have to configure the modules.

The modules

When the cx88xx module is loaded, we need to set the card number to 19.

In Gentoo, as root:

# cd /etc/modules.d
# echo options cx88xx card=19 > cx88
# modules-update

All this does is manage the /etc/modules.conf file, so if you're running another flavour of Linux, just add the options text to the modules.conf file.

We need to autoload the modules when booting so add cx8800 and cx88-dvb to your /etc/modules.autoload.d/kernel-2.6 file.

That's it. Time to reboot your system. You should notice some DVB diagnostics appearing when you're coming back up. Good, good, good. If you have two cards, check that they're both recognised correctly.

Creating channels.conf

Just to help you get up and running, I'll show you how to get a working channels.conf file for your location. The channels.conf file is *very* much needed if you're going to use mplayer, which you most probably will. You'll need to install some more software.

On Gentoo, as root:

# emerge linuxtv-dvb-apps

or grab the source files from linuxtv.org

As yourself, a non-root user and using the correct file for your location:

% dvbscan /usr/share/dvb/dvb-t/au-Melbourne | tee channels.conf

Woohoo, you now have a channels.conf file which you now place in your ~/.mplayer directory. Give it a go:

% mplayer -vf lavcdeint "dvb://ABC TV"

Voila, you now have a working digital TV on your Linux box.

I have aliases set up for my own ease of use.

alias tv2='mplayer -vf lavcdeint "dvb://ABC TV"'
alias tv2.2='mplayer -vf lavcdeint "dvb://ABC2"'

...and so on.

Extras...

Besides mplayer, I also use the following:

Mythtv is the best and worst of opensource programming. It works, sort of, but you'll have to invest an awful lot of time setting it up and keeping it going. It was a while since I wrote that and lately, it's been pretty good: no dramas, no worries... it just works. Well done.

Kaffeine is a pretty handy TV application. Enter the channel configuration, press scan and start watching TV. Also has an instant record facilty. It's a bit buggy though but great for instant TV viewing with recording and timeshifting abilities. Again, lately Kaffeine has been very, very good and is now what I use for watching TV on my desktop. Well done to the crew doing Kaffeine.

I hope you've managed to get some useful information from here. Cruising the web, getting bits of useful information from here and there isn't much fun, so I thought I'd add to it ;-) Feedback to gro.dnomegduf@kcabdeefbvd will be appreciated.

Fudge
3 Nov 2007