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发布时间：2024-10-23 21:25
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热心网友
时间：2024-10-24 02:07
Special digital set-top boxes are available for receiving digital television broadcasts on TV sets without a built-in digital tuner. These boxes are particularly useful for systems like direct broadcast satellite (mini-dish) services, where they function as integrated receiver/decoders (IRDs).
For digital terrestrial television in the UK, digital set-top boxes are typically used to access services such as Freeview, operated by the Freeview Consortium. They also work with digital satellite providers like BSkyB and digital cable. These boxes enable viewers to access television, audio, and interactive services through features like the "Red Button" provided by broadcasters like the BBC and Sky.
However, current Freeview set-top boxes and televisions cannot decode the DVB-T2 protocol, which will be used for terrestrial high-definition broadcasts starting in 2009. Viewers will need to purchase an HD receiver when the transition occurs.
Set-top boxes are essential in Australia for receiving digital terrestrial broadcasts, as few television sets have built-in digital tuners. Foxtel set-top boxes, including the Foxtel iQ unit, are also used for subscription television services. For HDTV, media centers from Beyonwiz, which are available since March 2007, are employed.
In the United States, a very basic coupon-eligible converter box is supported through a $40 federal subsidy to encourage viewers of over-the-air television to adopt ATSC standards before the planned shutdown of full-power analog broadcasts in February 2009. These boxes are not readily available in Canada and Mexico, where digital television transition is not required, but ATSC-capable tuners are increasingly appearing in new TVs and related procts like computer video capture cards, satellite receivers, and DVD recorders globally.
Some digital set-top boxes also include a built-in digital video recorder (DVR), which leverages electronic program guide scheling data and records content to an internal hard drive.
（电视机的）机顶盒。