Pick a Free OS

Linux and the TV

About eight years ago, everybody was talking about the

convergence of technology. Computers had just gained the status

of "Multimedia" machines. One could watch full motion,

high-resolution videos in tiny 320x200 windows played off a

massive 650mb cdrom disc and listen to exciting FM quality music

from tinny 8 bit cards. And then someone realized that every

device on earth could be integrated into the computer. One can

now find integrated 3d video cards, audio cards, mpeg decoders,

internal modems, web cams, pluggable microwave (huh?), and most

importantly, TV Tuner Cards.

TV Tuner cards have existed for quite some time. Today one can

pickup a TV tuner card for less than $50 or even find it

integrated in the 3D/2D video card. Before you throw your TV set

off the terrace, it would be worth contemplating the fact that

most TV Tuner cards can hardly match the quality of any decent TV

set. Unlike TV sets, which run on an analog system and do not

rely on image precision, computer CRTs have to display images

with a lot more detail. In most cases due to the low resolution

of broadcasts, the computer CRT cannot display a sharp image.

Computer CRTs display colors, relatively less sharply and

vibrantly compared to TV sets.

A TV Tuner card has three important components. The tuner chip is

used to "listen" to a specific broadcast frequency. Most cards

have major problems tuning weak signals, especially when an

antenna is the input source. A video decoder chip processes the

incoming signal and processes the broadcast format

(PAL/NTSC/SECAM) and pushes it to an overlay area of the main

video card. The overlay area is a part of the video memory which

is directly written onto by the TV tuner to display the TV

channel. Finally a sound decoder chip, processes the audio

signals and can additionally decode Stereo/Dolby signals before

feeding it to the speakers.

If you do however have the money, a TV card is a cool gadget to

have on your computer. Besides catching up on news or sports

while using some software, you can also receive

S-Video/Composite/RF signals and perform video/frame capture.

Getting your TV card running under Linux is not very difficult.

However there is a lack of easily available documentation on the

Internet. The standard bttv driver provided with most kernels has

limited support for tuner cards.

This document will focus on getting your TV tuner card working