- المجال:
- Number of terms: 20560
- Number of blossaries: 0
- Company Profile:
Tektronix provides test and measurement instruments, solutions and services for the computer, semiconductor, military/aerospace, consumer electronics and education industries worldwide.
An individual horizontal sweep across the face of the display by the electron beam. It takes 525 of these scan lines to make up a single frame of an NTSC picture and 625 for PAL.
Industry:Software
A simple picture intended to be superimposed over the video. Display size varies but is bound to CCIR 601 picture dimensions (720 x 480 for NTSC-rate displays or 720 x 576 for PAL-rate displays).
Industry:Software
Operation where the bit rate changes with time during the decoding of a compressed bit stream. Although variable bit rate is acceptable for plain linear playback, one important consideration not to use variable bit rate is that reasonably quick random access becomes nearly impossible. There is no table of contents or index in MPEG. The only tool the play back system has for approximating the correct byte position is the requested play back time stamp and the bit rate of the MPEG stream.
MPEG streams do not encode their play back time. To approximate an intermediate position in a variable bit rate stream, the play back system must grope around near the end of the stream to calculate the playback time, and assume the stream is approximately constant bit rate. The groping around for the correct position can take several seconds. This is not appropriate for an interactive presentation or game. This groping around is, at least, annoying when trying to view a portion of a movie but it is not even possible for video streams because there are no time stamps (the SMPTE. time codes in video streams need not be continuous or unique).
Audio streams are always fixed bit rate.
Industry:Software
The hardware (and software in AVC) package which expands the standard pattern system to include rotary wipes, and rotating patterns (and matrix wipes in AVC).
Industry:Software
RealAudio is an on-line audio software platform, from the company Progressive Networks, dedicated to audio links on the Internet via 14.4 kbit/s, 28.8 kbit/s or faster connections. RealAudio software features a player, a server, and development tools, and is available for Windows, Unix, and Apple Macintosh environments.
Industry:Software
a) A MAC standard proposed for studio intraconnection by the SMPTE working group on CAV standards. The S-MAC system uses time compression and time-domain multiplexing techniques to convey (Y, CR, CB) video signals - a version of (Y, R-Y, B-Y). b) A MAC designed for single transmission of CAV signals in a television facility or between facilities. See also MAC.
Industry:Software
A technique used in many ATV schemes (including all of the MACs) for squeezing a signal of a certain duration into a time period of lesser duration. This effectively multiplies the bandwidth of the original signal by the compression factor. If the higher bandwidth is not available, horizontal resolution is lost. Time compression is most frequently used for color components (which can often afford the resolution loss due to restricted visual acuity) and for widescreen panels (with the resolution loss made up via some sub-channel).
Industry:Software
For a definition of “TV” column codes.
See Terrestrial Transmission Standards.
(
Industry:Software
SVM is one of the many tricks manufacturers use to get more light out of a picture tube, at the cost of real picture detail. It changes the speed or velocity of the beam as it is scanned from the left to the right side of the picture. In the process, it distorts real picture detail, causing dark areas of the picture on light backgrounds to be reproduced much larger than normal and light areas on dark backgrounds to be reproduced much smaller than normal. When the beam spends more time “writing” light areas, the phosphors receive more energy and produce more light output. The fact that this will contribute to phosphor blooming, as well as detail distortion seems to be lost on a number of manufacturers calling it a “feature.” The presence or absence of SVM can be easily detected by displaying the needle pulse test pattern. In the test pattern, the width of the white line on the black background, and black line on the white background are the same. In a set with SVM, the width of the black line will be much larger than the white line. If SVM is found on a set, look for an ability to turn it off. Several sets provide this option in the mode of the set designed to accurately reproduce the signal source. In some other sets, it is easily defeated by a qualified service technician.
Industry:Software
