HDTV Contemporary systems

Main article: Large-screen television technology

Components of a typical satellite HDTV system:
1. HDTV Monitor
2. HD satellite receiver
3. Standard satellite dish
4. HDMI cable, DVI-D and audio cables, or audio and component video cables

Besides a HD-ready television set, other equipment is needed to view HD television. Cable-ready TV sets can display HD content without using an external box. They have a card slot for inserting a CableCARD.^[17].

High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, high definition discs (BD and HD DVD), internet downloads and the latest generation of video game consoles.

Recording and compression

Main article: High-definition pre-recorded media and compression

HDTV can be recorded to D-VHS (Data-VHS), W-VHS (analog only), to a HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD recorders), or a HDTV-ready HTPC. Some cable boxes are capable of receiving or recording two broadcasts at a time in HDTV format, and HDTV programming, some free, some for a fee, can be played back with the cable company's on-demand feature. The massive amount of data storage required to archive uncompressed streams make it unlikely that an uncompressed storage option will appear in the consumer market soon. Realtime MPEG-2 compression of an uncompressed digital HDTV signal is also prohibitively expensive for the consumer market at this time, but should become inexpensive within several years (although this is more relevant for consumer HD camcorders than recording HDTV). Analog tape recorders with bandwidth capable of recording analog HD signals such as W-VHS recorders are no longer produced for the consumer market and are both expensive and scarce in the secondary market.

In the United States, as part of the FCC's "plug and play" agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" Firewire (IEEE 1394) upon request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes, but some cable TV companies have. As of July 2004, boxes are not included in the FCC mandate. This content is protected by encryption known as 5C.^[18] This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all fair use of the content.

http://en.wikipedia.org/wiki/High-definition_television