Forkortelser innen dagligtale er en selvfølge, men hva betyr alle? Håper dere er med å bidra her i denne tråden.
LASER = Light Amplification by Stimulated Emition of Radiation.
Viser resultater 1 til 7 av 7
10-02-2004, 00:55 #1
Forkortelser - Her er de alle listet
10-02-2004, 01:09 #2
Noen ganger må man bare Google
Her er iallefall litt å lese og tenke på.
Du finner igjen en hel del i denne teksten som du sikkert har hørt før og lurt på hva det egentlig betyr. Iallefall gjorde jeg det.
Scientific-Atlanta, Inc. 1
Frequently Asked Questions
1. What is HDTV? HDTV stands for High-Definition Television.
2. What is Aspect Ratio? Aspect ratio is the width of a picture relative to its height. 4:3 and 16:9 are common aspect ratios. HDTV Is 1/3 Wider Than NTSC 16 49 3HDTV NTSC Extra Picture The majority of current NTSC transmissions are 4:3 aspect ratio. Virtually all HDTV transmissions are in 16:9 aspect ratio.
3. What is the ATSC? ATSC stands for the Advanced Television Systems Committee. It was responsible for defining the 18 different formats of HDTV. It was formed to develop technical standards for advanced television systems, including high-definition television. The ATSC specifies MPEG2 for video compression and AC-3 (more commonly known as Dolby Digital) for audio compression. The 18 formats of HDTV are as follows: Scan Lines PixelizationFrame Rate Aspect Ratio Formats 525 Total 480 Active 480 x 640 24p, 30p, 60p, or 60i fps 4:3 4 SDTV 525 Total 480 Active 480 x 704 24p, 30p, 60p, or 60i fps 4:3 or 16:9 8 (4x2) 750 Total 720 Active 720 x 1280 24p, 30p, 60p 16:9 3 HDTV 1125 Total 1080 Active 1080 x 192024p, 30p, 60i 16:9 3
Generally all HDTV ready monitors or integrated HDTV sets are capable of supporting an SDTV (480i) signal. Some also support a 480P signal. Not all HDTV monitors support both 720P and 1080i HDTV signals. For instance, some plasma displays only support 720P.
4. What is MPEG? MPEG stands for Motion Picture Experts Group, the standard settings body that developed the video and audio compression standards used in today’s digital television transmissions. MPEG has several different standards for video compression. MPEG1 was the original compression standard meant for use in computers. MPEG2 was developed for broadcast television applications. MPEG2 has several profiles and levels.
5. What is MP@ML? This stands for main profile at main level. This is the format used for most standard-definition digital channels. It supports resolutions up to 720 x 480i and data rates up to 15 Mbps.
6. What is MP@HL? This stands for main profile at high-level. This is the format used for high-definition digital channels. It supports resolutions up to 1920 x 1080i and data rates up to 19.25 Mbps.
7. What is Interlaced Scanning? Interlaced scanning is a broadcast process used in TV sets in which half the lines are transmitted as one field and the other half is transmitted as the second field. These two fields are displayed sequentially to form an image. High-definition television has several scan rates. The most common of these is broadcast at a total of 1125 interlaced lines, of which 1080 of those lines are visible (hence the term 1080i).
8. What is Progressive Scanning? Computer monitors typically use progressive scanning. This scanning process paints all the horizontal scan lines on the screen at one time. The other common scanning scheme used in HDTV is broadcast at 750 progressive lines, of which 720 of those lines are visible (hence the term 720P). Some television broadcasters have chosen to broadcast 525 progressive lines, of which 480 of those lines are visible (hence the term 480P). Many DVD players output the picture in 480P format.
9. What is Scan Rate? Scan rate has two components. There is a vertical scan rate and a horizontal scan rate. The vertical scan rate is the number of frames/fields per second transmitted. The horizontal scan rate is the number of horizontal lines of video transmitted per second. The vertical frame rates supported in the ATSC specification are 24P, 30P, 60P, and 60i.
10. What is Frame Rate? A frame of video is a complete image in a sequence of images. The frame rate is the number of frames transmitted every second.
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11. What is Data Rate? How Does it Impact Video Quality? The data rate is the number of bits per second used to transmit a video and audio stream. The ATSC specification calls for 19.25 Mbps data rate for a high-definition terrestrial transmission. However, some cable/satellite broadcasters use a lower data rate since most of these transmissions are movies without a lot of high-speed motion. Generally, a higher data rate will translate to better video quality, especially with high-speed motion scenes. For content such as movies, you most likely would not be able to tell the difference between a data rate of 12 Mbps and one of 19 Mbps. For content such as sports, you probably would see a difference between those data rates.
12. What Does Component Video Mean? It means that video is represented as three different components which may be combined in an HDTV to provide video. There are different component video formats such as YPbPr and RGB.
13. What Does YPbPr Mean? YPbPr is the component video format in which the luminance (Y) is represented separately from the color components (Pb and Pr). The majority of HDTV’s today support this format. These HDTV’s accept the YPbPr formatted video per EIA specification 770.3. The Y output on HDTV’s and HDTV receivers is provided as a Green jack, the Pb is provided as a Blue jack, and the Pr is provided as a Red jack. The colors themselves are not to be confused as an RGB output.
14. What Does RGB Mean? RGB is the component format in which the primary colors (red, green, and blue) are transmitted as three independent components. Some older HDTV monitors have only RGB inputs. Monitors with RGB inputs also require separate horizontal and vertical sync inputs.
15. What are the Differences Between an HDTV and an SDTV? Some of the differences between and HDTV and a regular TV are summarized in the chart below: NTSC HDTV (ATSC) Total Lines 525 1125 (Interlaced) or 750 (Progressive) Active Lines 480 1080 (Interlaced) or 720 (Progressive) Sound 2 Channels (Stereo)5.1 Channels (Surround) Aspect Ratio 4:3 16:9 Max. Resolution 720 x 480 1920 x 1080 Pixels Rectangular Square HDTV is a digitally delivered signal whereas SDTV had historically been delivered as an analog signal; however it is now being delivered digitally in many cable and satellite systems. An HDTV signal provides six times the number of pixels than an SDTV signal, resulting in a much sharper image on the display.
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16. What Does DVI Mean? What is HDCP? What is HDMI? DVI stands for digital visual interface. DVI is an all-digital link between a video/audio source such as an HDTV set-top and a display device such as an HDTV. The DVI link provides an uncompressed digital stream at rates up to 5 Gbps between the two devices. The DVI link does not contain audio, and as such, audio still need to be connected from the set-top to the HDTV or home theatre system. One advantage of DVI is that the link allows graphics to be sent along the link as well. This allows the user interface from the set-top to be displayed on the HDTV. The DVI 1.0 connector and cable on the set-top and HDTV looks as follows: Drawing Courtesy of Silicon Image HDCP stands for High-Bandwidth Digital Content Protection. HDCP is the copy protection standard that is tied to DVI. HDMI is the next generation of DVI. HDMI stands for High-Definition Multimedia Interface. The main difference between HDMI and DVI 1.0 is that HDMI adds audio to the DVI link and is a smaller connector. The HDMI interface will be backwards compatible to the DVI 1.0 interface, meaning that you can connect up a set-top to an HDTV, where one has DVI 1.0 and the other has HDMI. HDMI is not expected in HDTV’s until 2004. The HDMI connector and cable on the set-top and HDTV will look as follows: Drawing Courtesy of Silicon Image Scientific-Atlanta, Inc. 4
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1. How Many HDTV’s Have Been Shipped to date in North America? Through the end of 2001, approximately 2.5 million HDTV’s (includes monitors and integrated receivers) had been sold. The forecast for 2002 is 2.1 million units. A total of 30 million units are expected to be sold over the next five years. Source: Consumer Electronics Association
2. Are Local TV Stations Broadcasting in HDTV? There are many local TV stations that are transmitting digital signals now. However, just because a station is transmitting a digital signal does not mean it is transmitting an HDTV signal. Some stations are using the new bandwidth to broadcast several standard-definition channels. Most stations however, once they begin broadcasting in digital are offering HD content from their parent station (i.e. CBS, ABC, NBC, Fox, WB, UPN, or PBS).
3. What is the Schedule for Broadcasters to Transmit in HDTV? The FCC had required all commercial stations in the U.S. to be broadcasting in digital by May 1, 2002. To date, 422 stations are now broadcasting a digital signal. Digital television signals are now being broadcast in 128 markets which comprises 87.13% of U.S. TV households. In addition, 45% of U.S. TV households live in markets where there are four or more broadcasters delivering a digital signal.
4. What Cable Channels are Available in HDTV? Currently, HBO and Showtime have high-definition channels. The Discovery Channel also just launched HD service. Many cable systems offer local channels that have HD content also.
5. What Satellite Channels are Available in HDTV? Satellite generally offers the same HDTV channels as cable. DirecTV has had an exclusive HD channel called HDNet. However, HDNet is working on agreements with cable operators and is expected to begin service in some cable systems in 2002.
6. Do EchoStar and DirecTV Offer HDTV Programming? Yes
7. Why are Some HDTV’s 4:3 Aspect Ratio and Others 16:9? There has been no set standard for TV manufacturers to follow. True HDTV is widescreen 16:9 aspect ratio; however, there are many 4:3 models that are offered by the TV manufacturers. System Requirements 1. How Much Channel Bandwidth Is Required for HDTV? A full HDTV stream occupies 3 MHz of channel bandwidth. This equates to a data rate of 19.25 Mbps. Generally, two HDTV streams can be placed into one 6 MHz chunk of bandwidth provided that the stream is QAM modulated at a QAM 256 rate.
10-02-2004, 01:11 #3
VGA=Video Graphics Array
10-02-2004, 01:13 #4
The High-Definition Multi-media Interface (HDMI) is an industry-supported, uncompressed, all-digital audio/video interface. HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, DVD player, and A/V receiver and a compatible digital audio and/or video monitor, such as a digital television (DTV).
HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC The Advanced Television Systems Committee (ATSC) is the group that helped to develop the new digital television standard for the United States, also adopted by Canada, and being considered by Mexico and other countries. It is a competitor to the more widely used DVB standards.
The ATSC standard uses AC-3 (Dolby Digital) audio. It allows for the transmission of multiple channels of information per analog channel. For example, the UHF channel 35 might carry up to 4 standard-definition programs.
..... Click the link for more information. HDTV High Definition Television (HDTV) means broadcast of television signals with a higher resolution than traditional formats (NTSC, SECAM, PAL) allow. Its introduction coincides with that of digital television (DTV).
Technical detailsThe HDTV screen uses a 16:9 aspect ratio. The high resolution images (1920 pixels × 1080 lines or 1280 pixels × 720 lines) allow much more detail
..... Click the link for more information. standards and supports 8-channel digital audio, with bandwidth to spare to accommodate future enhancements and requirements.
A high-bandwidth version of the standard 19-pin Type A HDMI connector, called Type B, has been defined, although it is not yet in common use. This has 29 pins, allowing it to carry an expanded video channel for use with high-resolution displays.
Type A HDMI is backwards-compatible with the single-link Digital Visual Interface The digital visual interface (DVI) is a form of video connector made to maximize the display quality of flat panel LCD computer monitors and high-end video cards. It was developed by an industry consortium, the Digital Display Working Group (DDWG).
Existing standards, such as VGA, are analog, as are the monitors they are plugged in to. However, LCD monitors and plasma screens internally use a digital signal. Using VGA cabling results in the computer signal being converted from the internal digital format to analog on the VGA cable, then back to digital in the monitor for display. Obviously a better solution, provided by DVI, is to simply supply the original digital signal to the monitor directly.
..... Click the link for more information. (DVI) used on computer monitors and graphics cards. This means that a DVI source can drive an HDMI monitor, or vice versa, by means of a suitable adapter or cable, but the audio and remote control features of HDMI will be unavailable. Type B HDMI is similarly backwards-compatible with dual-link DVI.
The HDMI Founders include leading consumer electronics manufacturers Hitachi, Matsushita Electric Industrial (Panasonic), Philips, Sony, Thomson (RCA), Toshiba, and Silicon Image. Digital Content Protection, LLC (a subsidiary of Intel) is providing High-bandwidth Digital Content Protection (HDCP HDCP (High-bandwidth Digital Content Protection) is a specification developed by Intel Corporation to "protect" digital audio and video content as it travels across Digital Visual Interface (DVI) or High Definition Multimedia Interface (HDMI) connections. The HDCP specification is proprietary and implementation of HDCP requires a license.
HDCP is licensed by Digital Content Protection,
..... Click the link for more information. ) for HDMI. In addition, HDMI has the support of major motion picture producers Fox, Universal, Warner Bros. and Disney, and system operators DirecTV, EchoStar (Dish Network) as well as CableLabs.
10-02-2004, 01:17 #5
Hadde vært greit å sitte i stolen til "Vil du bli millionær?" på 1.000K og fått spørsmålet: Hva står forkortelsen VGA og LASER for.
Greit å vite at man da enkelt svarer: Light Amplification by Stimulated Emition of Radiation og Video Graphics Array.
10-02-2004, 01:29 #6
10-02-2004, 01:36 #7
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