MediaSonic MS9000, Руководство пользователя

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HD Player Index
107 Rev. 6.4
A Black burst signal contains vertical sync, horizontal sync and chroma burst
information.
Block
•
Rectangular area of picture, usually 8 x 8 pixels in size, which are
individually subjected to DCT coding as part of a digital picture
compression process.
•
Artifact of compression generally showing momentarily as misplaced
rectangular areas of picture with distinct boundaries.
This is one of the major defects of digital compression, its visibility generally
depending on the amount of compression used, the quality of the original signal,
and the quality of the encoder. The visible blocks may be 8 x 8 DCT blocks or
"misplaced blocks"-16 x 16 pixel macroblocks, due to the failure of motion
prediction/estimation in encoder or other motion vector system, such as a
standards converter.
See also: DCT, JPEG, Macroblock, MPEG-2.
Brightness
This is the intensity of the video level and refers to how much light a display
emits.
Byte A group of data bits that are processed together. Typically, a byte consists of 8,
16, 24 or 32 bits.
1 Byte = 8 bits = 256 discrete values (brightness, color, etc.)
1 kilobyte = 1,024 bytes: (not 1000 bytes)
1 Megabyte = 1,048,576 bytes: (not 1 million bytes)
1 Gigabyte = 1,073,741,824 bytes: (not one billion bytes)
1 Terabyte = 1,099,511,627,776 bytes: (not one trillion bytes)
A full frame of digital television, sampled according to ITU-R 601, requires just
under 1 Mbyte of storage (701 kbytes for 525 lines, 829 kbytes for 625 lines).
HDTV frames are 4 - 5 times larger. Digital film frames may be that much larger
again.
CBR
Constant bit rate. CBR refers to the delivery of multimedia where there is
dedicated bandwidth and the data can be delivered at a guaranteed constant bit
rate. MPEG-1 and 2 are designed for CBR delivery. Constant bit rate cannot be
assured on the Internet or most Intranets. Protocols such as RSVP are being
developed and deployed to provide bandwidth guarantees.
CCIR Comité Consultatif International des Radio Communications (International
Radio Consultative Committee), an international standards committee no longer
in operation and replaced by the International Telecommunications Union (ITU).
CCIR-601 See : ITU-R BT.601-2.
Chroma
An NTSC or PAL signal is composed of two parts, which make up the picture.
The black and white portion (or Luma) and the color portion (Chroma).
Codec Coder-decoder. A device that converts analog video and audio signals into a
digital format for transmission over telecommunications facilities and also
converts received digital signals back into analog format.
Color bars A test pattern used to check if a video system is calibrated correctly. A video
system is calibrated if the colors are the correct brightness, hue and saturation.
Color depth
The number of bits used to represent the color of a pixel and thus how many
colors can be displayed. Color depth is typically 8-, 16-, or 24-bit. 8-bit would
give 256 colors. A high color pixel requires at lest 24-bit color (1.1164 billion
colors).