Aspect Ratio - the ratio of image width to image height. The term may apply to the display device configuration, or the shape of the content being displayed. (See Letterboxing) HDTV uses an aspect ratio of 16 units wide by 9 units high. Conventional television programming and displays are at an aspect ratio of 4 - 3. Digital SDTV programs may aspect ratios from 4 - 3 to 16 - 9, dependant on content and its source (e.g. upconverted NTSC is likely to be 4 - 3).
DTH - Direct-to-Home satellite delivery. May also be called DBS or Direct broadcast satellite. In Canada, Bell ExpressVu and Star Choice provide DTH services in both HDTV and SDTV.
Datacasting - The inclusion of additional data in the broadcasting stream. Such data may be related to the current program (e.g. sports statistics) or may be completely independent (e.g. software downloading or traffic advisories).
Fire Wire - A digital interface originated by Apple Computer that can transport data at 100, 200, or 400 Mbps. It is widely used to interconnect digital video devices, such as cameras and displays. Also referred to as IEEE- 1394.
SDTV - "Standard Definition Television." SDTV are based on 480 lines of vertical resolution and may have either 4 - 3 or 16 - 9 aspect ratios, and surround sound. Several SDTV programs are sent together to form the simulcast bundle. While SDTV pictures are of significantly better quality than NTSC, they are not up to the standard of HDTV.
Simulcast - The broadcast of the same program simultaneously over two or more different systems or channels, such as in HDTV and in NTSC. CRTC regulations require today that broadcasters simulcast much of their schedules.
D-ILA - (Direct-drive Image Light Amplifier) (see LCOS)
DTVLink - This logo is on equipment that has IEEE 1394 and DTCP.
Dolby Digital 5.1 - Also known as AC-3, it provides 6 channels of sound: left, center, right, left rear, right rear, and sub-woofer. It is also called "5.1 channels" since the 6th channel has reduced bandwidth. Dolby Digital 5.1 is the audio standard for all U.S. digital TV stations, most DVDs, some DBS programs, and many theaters.
LFE - (Low Frequency Effects) - Sub-woofer. The 6th channel in a 5.1 channel system.
RGB - 1. red-green-blue - 2. a 3-wire standard