B-MAC[1] is a form of analog video encoding, specifically a type of Multiplexed Analogue Components (MAC) encoding. MAC encoding was designed in the mid 80s for use with Direct Broadcast Satellite systems. Other analog video encoding systems include NTSC, PAL and SECAM. Unlike the FDM method used in those, MAC encoding uses a TDM method. B-MAC was a proprietary MAC encoding used by Scientific-Atlanta for encrypting broadcast video services; the full name was "Multiple Analogue Component, Type B".
The simultaneous PAL transmission of all TV-picture elements and the multiplexed transmission of the TV picture elements with D2-MAC.Simulated MAC signal. From left to right: digital data, chrominance and luminance
B-MAC uses teletext-style non-return-to-zero (NRZ) signaling with a capacity of 1.625 Mbit/s. The video and audio/data signals are therefore combined at baseband.
Both PAL (626/50) and NTSC (525/60) versions of B-MAC were developed and used.
User base (PAL/NTSC zones)
This system was used in South Africa[2] and Australia[3] (for TVRO until 2000).
MAC transmits luminance and chrominance data separately in time rather than separately in frequency (as other analog television formats do, such as composite video).
Audio and Scrambling (selective access)
Audio, in a format similar to NICAM was transmitted digitally rather than as an FM subcarrier.
The MAC standard included a standard scrambling system, EuroCrypt, a precursor to the standard DVB-CSA encryption system.
HD-MAC, an early high-definition television standard allowing for 2048x1152 resolution.
DVB-S, MAC technology was replaced by this standard
DVB-T, MAC technology was replaced by this standard
Referencesedit
^Report 1074-1 - Satellite transmission of multiplexed analogue component (MAC) vision signals(PDF). ITU. 1990. p. 48.
^Conradie, D.G. (19 June 1988). "The SABC's TV/radio satellite distribution system". COMSIG 88@m_Southern African Conference on Communications and Signal Processing. Proceedings. pp. 51–55. doi:10.1109/COMSIG.1988.49301. ISBN0-87942-709-4. S2CID 131163463 – via IEEE Xplore.
^"Scientific-Atlanta's PowerVu Technology Helping AFRTS Expand the Delivery of A Touch of Home to Military Abroad" (Press release). Atlanta, GA: Scientific Atlanta. PR Newswire. Retrieved 2014-05-29.
External linksedit
Multiplexed Analogue Components in "Analog TV Broadcast Systems" by Paul Schlyter
December 15, 2023
form, analog, video, encoding, specifically, type, multiplexed, analogue, components, encoding, encoding, designed, with, direct, broadcast, satellite, systems, other, analog, video, encoding, systems, include, ntsc, secam, unlike, method, used, those, encodin. B MAC 1 is a form of analog video encoding specifically a type of Multiplexed Analogue Components MAC encoding MAC encoding was designed in the mid 80s for use with Direct Broadcast Satellite systems Other analog video encoding systems include NTSC PAL and SECAM Unlike the FDM method used in those MAC encoding uses a TDM method B MAC was a proprietary MAC encoding used by Scientific Atlanta for encrypting broadcast video services the full name was Multiple Analogue Component Type B The simultaneous PAL transmission of all TV picture elements and the multiplexed transmission of the TV picture elements with D2 MAC Simulated MAC signal From left to right digital data chrominance and luminanceB MAC uses teletext style non return to zero NRZ signaling with a capacity of 1 625 Mbit s The video and audio data signals are therefore combined at baseband Both PAL 626 50 and NTSC 525 60 versions of B MAC were developed and used User base PAL NTSC zones This system was used in South Africa 2 and Australia 3 for TVRO until 2000 B MAC was used for satellite broadcasts of the American Forces Radio and Television Service from the early 1980s until 1996 1997 when the analogue standard was replaced by the digital PowerVu system 4 B MAC has not been used for DTH applications since Primestar switched to an all digital delivery system in the mid 1990s Contents 1 Technical details 2 See also 3 References 4 External linksTechnical details editMAC transmits luminance and chrominance data separately in time rather than separately in frequency as other analog television formats do such as composite video Audio and Scrambling selective access Audio in a format similar to NICAM was transmitted digitally rather than as an FM subcarrier The MAC standard included a standard scrambling system EuroCrypt a precursor to the standard DVB CSA encryption system See also editAnalog high definition television systems PAL what MAC technology tried to replace SECAM what MAC technology tried to replace A MAC B MAC C MAC D MAC E MAC S MAC D2 MAC HD MAC an early high definition television standard allowing for 2048x1152 resolution DVB S MAC technology was replaced by this standard DVB T MAC technology was replaced by this standardReferences edit Report 1074 1 Satellite transmission of multiplexed analogue component MAC vision signals PDF ITU 1990 p 48 Conradie D G 19 June 1988 The SABC s TV radio satellite distribution system COMSIG 88 m Southern African Conference on Communications and Signal Processing Proceedings pp 51 55 doi 10 1109 COMSIG 1988 49301 ISBN 0 87942 709 4 S2CID 131163463 via IEEE Xplore 8 3 Multiplexed Analogue Components Transmissions happy emu id au Scientific Atlanta s PowerVu Technology Helping AFRTS Expand the Delivery of A Touch of Home to Military Abroad Press release Atlanta GA Scientific Atlanta PR Newswire Retrieved 2014 05 29 External links editMultiplexed Analogue Components in Analog TV Broadcast Systems by Paul Schlyter Retrieved from https en wikipedia org w index php title B MAC amp oldid 1176248016, wikipedia, wiki, book, books, library,
