Downconvert - The process which reduces the number of pixels in the scanning format used to represent an image, so that it may be reproduced on a display of lower resolution, such as a conventional television. For example, an HDTV image may be downconverted to an SDTV or NTSC image, but in the conversion significant detail information may be lost.
MMDS - Multichannel, Multipoint Distribution System. A wireless cable system capable of being encoded for pay-per-view and subscriber services.
Pixel - A picture element; a single displayable video dot. HDTV requires from 1 to 2 million pixels in the display for full resolution images to be shown.
Component video. This 3-wire convention was created for connecting DVD players to TVs or monitors. It avoids downgrading the signal to NTSC. The signals may be RGB or YPrPb. Some HD STBs have only component video output.
Line Doublers - This device converts NTSC or 480i into 480p. Line doublers with motion-adaptive processing can to an extent turn a 30 frames/sec image into a 60 frames/sec image, thus removing some of the jerkiness and blurriness associated with motion.
Multi-path interference - Some neighborhoods are plagued with this problem: - The signal finds more than one path to the antenna. Multi-path results from reflections off of buildings and diffraction around the sides of hills. For NTSC sets this will result in ghosts: multiple images shifted laterally. For DTVs the result can be an unusable signal, even though it may be strong. The solutions are moving the antenna or selecting a very directional antenna. Newer generations of DTV receivers are better able to cope with multi-path.
NTSC - NTSC is the acronym that stands for National Television Systems Committee"and the name of the current analog transmission standard used in the U.S., which the committee created in 1953.
Upconverting - Process by which a standard definition picture is changed to a simulated high-definition picture.
