Tutorial: Using TV Tuner Cards Under Linux

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.