TV tuner card

A TV card (or TV card ) is a generalized term for a computer expansion cards that are used to display TV signals on a screen or recorded on the hard disk. Also, there are solutions for connecting via ExpressCard or USB, which are especially interesting for notebooks. A distinction is made between products that receive terrestrial and cable television signals and others who may be directly connected to a satellite cable. For satellite use Cards that comes with a remote can be interposed.

Cards for analog terrestrial television and cable television

  • TV tuner: A TV card with built-in analog TV tuner ( tuner) TV station can receive from a home antenna or cable TV. The channel selection is performed by software. The tuner of some TV cards can also receive radio stations on the FM band in addition to television stations, in which case the audio signal is digitized at the tuner output.
  • Video Overlay: Older TV cards ( video overlay cards) generate the analog monitor signal itself and mix it together with the signal from the graphics card. The disadvantage here is that the latter often suffers, resulting in a graphic is blurred or darkened. Newer TV cards, however, write the image information directly into the frame buffer of the graphics card. The difference with TV tuner cards is that video overlay the signal can not search for it themselves and similar assistance by software need.
  • Genlock Interface: Some TV cards also offer the possibility to produce an analog video signal. In this case for video signal displayed cover images or a second video signal are mixed.
  • Hardware encoder: Some TV cards provide the ability to compress the video while recording in hardware. This relieves the processing during recording. Another option would be uncompressed capture the video and compress only in retrospect. Subsequent compression is anyway necessary if one extra editing (eg denoising and de -interlace ) recording or want a codec preferred to not support the hardware encoder.
  • Frame grabber: Because of the possibility to digitize analog video signals, TV cards are also somewhat inaccurately referred to as a frame grabber cards. However, pure frame grabber cards do not have a TV tuner, the analog composite or S -Video signal must be fed from an external source ( TV, TV tuner, video recorder, video camera).
  • Chipsets: The most common chipset was developed by Brooktree ( Conexant inzw ) with the names Bt848/849/878/879. This is supported by many popular operating systems.

Digital TV cards

Digital TV cards are available in cable TV DVB -C, DVB- T terrestrial and satellite DVB -S; combinations are also available. They include a DVB receiver; the radio is done by software. The received MPEG- 2 data stream differs from that of a DVD or Video CD only in details. He is decoded with inexpensive tickets by software and output on the graphics card, but also more expensive models have hardware MPEG -2 decoder. See also: DVB card.

To record a program, the data stream from a digital TV card only needs to a disk, due to the required memory capacity and write speed usually a hard disk is stored. In contrast, must be digitized for recording by an analog TV card analog video and audio signals and compresses computationally intensive real-time from the PC and then saved to disk. The recording via a digital TV card is independent of the type, therefore always with maximum quality. Only disturbances on the transmission path from the satellite, the DVB -T channels or from the cable TV network to the TV card reduce the quality of what is in picture and sound dropouts or " pixelated " images ( " blocks " in the picture) expresses. Also the requirements for the computer are much lower, which are avoided in computers with less computing power dropouts.

Relevance and future

In times in which winning online video and media libraries in importance and to provide for a number of TV content at any time on demand on the Internet, the question of the relevance and need for TV card is placed in trade publications increased. In fact, reports market research company InStat that in 2009, worldwide sales plummeted by 15%. However, expect to InStat, manufacturers of TV cards a sales boost by the arrival of Windows 7 with its improved integration of TV cards. In particular on the Windows Media Center here hopes ". Reinforce that Microsoft is advertising for TV card compatibility of the media center " " Manufacturers expect ," says InStat,

Even external providers have not been written off the TV card market. Thus, the Axel - Springer -Verlag has launched a software on the market in January 2010, specifically aimed at users of TV cards and works with Windows Media Center: In watchmi users can create personal channels, which then self-learning put together an individual program. The marketing of watchmi made ​​by the company "Axel Springer Media Impact". Apparently, started by watchmi user profiles to company or third party service provider are received, because watchmi should be able to be used by advertisers for targeting customers.

For purely analog TV cards, it will be only in Europe and other industrialized countries, a residual market, which is probably covered with used goods. Because of the conversion to digital TV ( DVB) will be to use only for the digitization of analog recorded movies analog TV cards. Only those cards that contain, in addition to an FM tuner, can still be used for a long time until the changeover to digital broadcasting for the recording of radio broadcasts.

Digital TV cards allow recording of TV content, regardless of the Internet. Since TV content on the Internet are often not available or only in a greatly reduced quality and a broadband Internet connection is required for transfers in streaming method, will probably remain a need for digital TV cards. For DVB -T or DVB -S reception also no cost is causative TV cable connection needed that is not already available in most rural areas.

Swell

  • Plug-in card
Electronic visual display S-Video Video-CD
628041
de