DavidTimms/DVBFedoraLegacy

Digital Television in Fedora

This page provides information on setting up a Fedora based system to operate with Digital Video Broadcasting tuner hardware, so that television programs can be viewed.

Introduction

In many parts of the world, television stations have begun transmitting digital television signals. While different digital transmission systems have been created, this document is about devices and viewers using the Digital Video Broadcasting (DVB) standard.

Typically, as digital TV is introduced to a region, the TV stations continue to transmit their older analogue signals, and add the newer digital TV signals on a previously unused TV channel. By adding a DVB compliant TV tuner to a PC, a Fedora PC will be able to access these channels. There is however, some setup of hardware, drivers, and application software required so that the full range of tuning channels, recording, watching and manipulation of off-air TV channels can be enjoyed.

Note: Since the Fedora distribution is based in a country where MPEG patents are recognised, it is not possible to play back DVB TV channels using only Fedora software. This guide shows how to use the external software repository RPM Fusion to provide pre-compiled software for the actual TV playback.

Hardware Setup

There are at least three major types of DVB tuner: PCI, USB and FireWire. Your choice about which type to use should depend on things like:

- do I have a PCI slot available ? (-> PCI)
- do I have a USB port available ? (-> USB)
- do I have a FireWire port available ? (-> Firewire)
- do I mind opening my PC up ? (-> PCI)
- do I want to be able to use the tuner on different 

PCs ? (-> USB, maybe Firewire)

- do I want it to be portable ? (-> USB)
- do I want it to be a clean installation ? (-> PCI)
- some notebook PCs might come with a miniPCI or USB tuner built-in.

In all cases, a good antenna signal, and cable will be required to plug into the RF antenna socket of the device; "rabbit ears" antennas might work in an area of excellent TV coverage.

PCI

Use the manufacturer's instructions to install the card into the system. When Fedora is booted, attempt to locate the device using grep Multimedia Find out more information by using the pci identifier listed in the previous result: {{{ lspci -v -s 01:09.0 }}} With luck this includes a line indicating the kernel module loaded that is handling the device, eg. bttv.

USB

Start a terminal session and {{{ su -c 'tail -f /var/log/messages' }}} Plug the tuner device into the machine. In the terminal some information about detection of the USB hotplug and perhaps some firmware and or driver loading activity will be seen. (To be improved ;-) Instead of lspci, use lsusb to determine which usb ID is the TV tuner device, and then use lsusb -v to determine more information about that item.

FireWire

(To be improved ;-) Need information on how this stuff works with FireWire.

Firmware

Some devices require the machine that they are plugged into to download the firmware into the device before the device can begin to work. Firmware for some devices might:

- be included inside the device; the device just works
- already be packaged as part of the kernel-firmware package
- be available as an internal something-firmware package 

within the Fedora software repository

- be available outside Fedora, but already packaged as an RPM
- be available as some other archive (perhaps the windows

driver disk), that needs to be manually extracted and placed in the appropriate place Various pieces of technology can assist with loading the device firmware. However, this relies on users reporting the steps needed to be taken to enable specific hardware. This includes getting information on lsusb/lspci device tables, HAL event triggers, and PackageKit software installation triggers.

Driver

All devices require a series of drivers to enable their capabilities. There will be a hardware specific driver eg. dvb_bt8xx, pvrusb2. This driver is often a kernel module, but it might have been accepted to be a part of the kernel proper, or might be an external compilable module. If the driver is already loaded, it may have been shown in the earlier lspci status example. If the driver is not loaded automatically, it will be necessary to read the manufacturer's instructions, web site and google to determine how to proceed.

If a driver makes it into the kernel-firmware package, it can then be trigger to load automatically when a device that it is known to support is detected.

DVB utilities

All the DVB drivers make use of the kernel DVB subsystem module dvb_core. There are user tools to work with the DVB subsystem. They are found in the dvb-apps package: {{{ yum install dvb-apps }}} To see what tools get installed: {{{ rpm -q --fileprovide dvb-apps }}} Use these tools to confirm correct detection and operation of DVB subsystem using the following tools.

Initial tuning data file

/usr/share/dvb-apps/dvb-t/country-location: provides an initial-tuning-data-file for a specific country-location If there is no initial file for your area, and you create one, it should be sent upstream to the dvb-apps authors.

scandvb

scan for all channels on all transponders (carriers) present in the the initial tuning data file, and create a channels.conf eg: scandvb /usr/share/dvb-apps/dvb-t/au-Coonabarabran If this creates output, then repeat it with: {{{ scandvb /usr/share/dvb-apps/dvb-t/au-Coonabarabran >channel.conf }}} to create the channels definition file.

Xzap

Uses the channels.conf to tune the frontend to a specific transponder (carrier) and demultiplex the particular channel. The preceding X represents either ATSC, Cable, Satelite, or Terrestrial

A status line is shown indicating information such as signal strength, bit error rate and so on. It is updated once each second.

femon

Shows the current tuning and decoding statistics of the tuner each second.

lowlevel recording of a digital TV station

Once a Xzap has tuned a station, another terminal window can be used to record DVB channel (aka MPEG2 Program Stream), to a file: {{{ cat /dev/dvb/adapterX/dvr0 >/mediastoragepath/programname.datetime.mpg }}}

Once that has run for a minute or so, press control-c to terminate the concatenation. The stream can then be viewed using any mpeg2 video decoding software.

DVB Application Software

Live TV playback

There are various mpg2 playback software available for Fedora, none of which are available in Fedora's own repos. Use an external rpm repository like RPM Fusion, by first enabling the repository. Since you will probably like to examine a few different applications to determine which is the most suitable for you needs: {{{ yum install mplayer-gui xine gstreamer-plugins-ugly w_scan dvbcut }}} ... please provide some simple usage information if you know how ;-)

The "ABC TV" name must exactly match the channel name in your channels.conf file.

- mplayer dvb://"ABC TV"
- xine dvb://ABC TV

Recording and scheduled recordings

{{{ yum install vdr-femon klear }}} ... please provide some simple usage information / page if you know how ;-)

Full TV / media recording and playback suite

{{{ yum install mythtv-suite }}} ... please provide some simple usage information / page if you know how ;-)

Updates

We hope this has been useful in getting your DVB hardware working with Fedora. In any case feel free to update text on this page or link to other references if you feel they would have helped you get your tuner going more easily ;-)