Set-top box
In entertainment electronics, a set-top box (abbreviated to STB , also known as an accessory device ) is a device that is connected to another - usually a television set - and thus offers the user additional options for use.
species
There are basically three types of add-on devices:
- Active ones that supply data or functions to the basic device without needing feedback from it themselves (e.g. video games , DVD player ).
- Passives that rely on the data or capabilities of the base device but do not provide any new functions themselves (rarely).
- Bidirectionals that have both active and passive capabilities (e.g. all types of recorders , as they are usually also playback devices).
Some types of STBs also communicate with each other and do not require the base unit for at least some of their functions (e.g. recording from a separate satellite receiver ).
The most important capabilities provided by STBs are playing media ( VHS , DVD , etc.), which may be interactive ( game consoles ), recording received data and receiving programs via alternative transmission channels ( satellite , Internet ) or methods ( digital , encrypted) ). Many functions initially only provided by STBs - especially active ones - are later (often only optional) integrated directly into the main devices. There are televisions with integrated VHS or DVD drives or DVB receiver (s).
Rather rare STBs are those that receive data from weather stations and process them graphically, or those that provide at least basic Internet access via the television set. There are also external advertising filters and home automation controls . Others, e.g. B. Teletext decoders or UHF converters are now extinct.
Products
A selection of available set-top boxes (alphabetically):
- Amazon Fire TV
- Apple TV
- d-box
- Dreambox - hard drive STB from Dream Multimedia
- Horizon
- Mediabox of the multimedia operating company (MMBG)
- Nvidia Shield TV
- ReelBox
- Roku Player
- SNES , PlayStation , Xbox - game consoles
- TiVo - PVR ( US and UK only )
- Xiaomi Mi Box S
connection
There are several types of interfaces to connect STBs to televisions and recorders. A classic, universal method is the use of a UHF modulator that generates its own TV channel that is transmitted via a coaxial antenna cable. In Europe, the French SCART connection became the most important type of analog connector and protocol, but S-Video was also of great importance. Sound inputs and outputs are also often designed as cinch sockets or plugs. In addition, there are often S / PDIF outputs for digital audio transmission. For digital image and data transmission, the industry relies on DVI , Firewire (also known as i.Link or IEEE 1394 ), Ethernet , SDI , HD-SDI and HDMI , the latter five standards also offer embedded audio . HDMI is the most widespread interface in the end-user sector today.
Development path
One or more set-top boxes are traditionally used to retrofit a more expensive item such as a television with missing functions, so that the new acquisition can be postponed. Since each additional set-top box makes the interaction more complex for the user, the most common function of set-top boxes is to integrate the natural development path into the main object. For example, today's televisions have many features that a few years ago required multiple set-top boxes. The user not only benefits from the fact that he can operate everything with a remote control, a status display and a menu, but also that mode changes are reduced and he only has to set one device.
criticism
In the operation of set-top boxes for television reception ( digital receiver , satellite receiver ) to conventional television sets , video and DVD recorders with terrestrial television - reception part there are some limitations:
- Basically, you automatically need an additional remote control to control another device. Most basic functions of the devices can be controlled via universal remote controls after appropriate configuration, but special operating steps usually still require the basic remote controls of all devices. If HDMI-CEC is implemented on the connected devices, it may also be possible to dispense with an additional remote control.
- Conventional video recorders do not offer the option of automatically selecting a program on the set-top box. The receiver and recorder must then be operated or programmed independently of one another.
- Televisions that rely on receiver set-top boxes are being degraded to mere monitors. Special functions such as channel preview and extended teletext functions are regularly lost and are replaced by the possibilities of the respective receiving device. Users of older television sets that are equipped with no or poor teletext can, however, experience added value in information provided that teletext is integrated in the DVB receiver.
- The mobility of portable devices is also restricted if a set-top box is also required.
Many of these problems can be traced back to the fact that at the beginning of digitization conventional television sets only had analog reception parts and were not prepared for DVB reception. In the course of the general changeover to DVB (analog PAL technology existed in satellite television in Germany until April 30, 2012), all television sets are now offered with integrated DVB receivers; Hard disk recorders with DVB receivers are available for recording DVB broadcasts .
See also
- Digital television in general
- Electronic Program Guide (EPG)
