PBS
Soon after the first World War in 1933, on May 8, 1933, the U.S. government established and operated radio station DZFM (then KZFM) in the Philippines on frequency 710 kHz with a power of 10,000 watts through the United States Information Service. In September 1946, two months after the Philippines became an independent country from the U.S.A., KZFM was turned over to the Philippine government. With the transfer was born the Philippine Broadcasting Service, PBS the second broadcasting organization after Manila Broadcasting Company.
The station was first operated by the Department of Foreign Affairs until it was transferred to the Radio Broadcasting Board (RBB) which was created by President Manuel Quezon on September 3, 1937. Meanwhile in the same year, an international telecommunications conference in Atlantic City, New Jersey, reassigned the letter "D" to replace the former "K" as the initial call letter for all radio stations in the Philippines. In January 1942, the RBB was abolished to give way to the establishment of the Philippine Information Council (PIC) which then assumed the function of the RBB, including the operation of DZFM. In turn, the PIC was abolished on July 1, 1952, and since then, until the creation of the Department of Public Information in 1959, DZFM and the Philippine Broadcasting Service (PBS) had been operated under the Office of the President.
Over the years hence, the PBS had acquired 13 more radio stations, one TV station which it time-shared with two other organizations, and changed its name to Bureau of Broadcast Services. At the same time that the BB was blazing a broadcasting trail now known as "network broadcasting", another government organization was building up its broadcast capability to rival, or in some instances, to complement, that of the BB. The National Media Production Center, NMPC, had acquired the facilities of the Voice of America in Malolos, Bulacan in 1965 and steadily brought the old complex up to standards by a steady overhaul, fine-tuning, and outright replacement of outmoded equipment and machines. The NMPC operated the Voice of the Philippines, VOP, on both medium wave-918 kHz and shortwave 9.810 mHz transmissions. In 1975, the NMPC obtained DWIM-FM. With this new station and some provincial stations that came under its wings earlier, the NMPC was a network and effectively covered a wide range of the Philippine listenership.
Public broadcasting in the Philippines was thus represented by the BB and the NMPC and catered to the educational and cultural needs of its audiences while endeavoring to keep it entertained with fare from indigenous material. Public service features were the keystone of its programs.
The BB and the NMPC were brought under one administrative roof in 1980 when the Office of Media Affairs was created to provide a loose union for both networks within the ABS-CBN Broadcast Center on Broadcast Drive in Quezon City. It was not an ideal situation, to say the least, since, as there had been no clear guidelines on the proper implementation of their respective operational strategies, the BB and the NMPC often squabbled, to the detriment of public broadcasting goals.
After the EDSA Revolution, the Office of Media Affairs was abolished, followed by the NMPC, and finally, the BB. In their stead was a plan, a vision, for one, single government broadcasting organization that would not be an echo device for the government, or much less, for any one man, but would instead dedicate itself to the service of the people through honest, balanced, and meaningful broadcasting.
That lay the blueprints and groundwork of the Bureau of Broadcast Services.
During Aquino administration, PBS transferred its office from ABS-CBN complex to PIA Building in Visayas Avenue.
Sunday, November 29, 2009
ISDBT
integrated Services Digital Broadcasting (ISDB) is a Japanese standard for digital television (DTV) and digital radio used by the country's radio and television stations. ISDB replaced the previously used MUSE "Hi-vision" analogue HDTV system.
ISDB is maintained by the Japanese organization ARIB. The standards can be obtained for free at the Japanese organization DiBEG website and at ARIB.
The core standards of ISDB are ISDB-S (satellite television), ISDB-T(terrestrial), ISDB-C (cable) and 2.6GHz band mobile broadcasting which are all based on MPEG-2 video and audio coding as well as the transport stream described by the MPEG-2 standard, and are capable of high definition television (HDTV). ISDB-T and ISDB-Tsb are for mobile reception in TV bands. 1seg is the name of an ISDB-T service for reception on cell phones, laptop computers and vehicles.
The concept was named for its similarity to ISDN, because both allow multiple channels of data to be transmitted together (a process called multiplexing). This is also much like another digital radio system, Eureka 147, which calls each group of stations on a transmitter an ensemble; this is very much like the multi-channel digital TV standard DVB-T. ISDB-T operates on unused TV channels, an approach taken by other countries for TV but never before for radio.
Video and audio compression
ISDB has adopted the MPEG-2 video and audio compression system. ATSC and DVB also adopted the same system. DVB and ISDB also provide for other video compression methods to be used, including JPEG and MPEG-4, although JPEG is only a required part of the MHEG standard. Brazil is using ISDB for terrestrial broadcasting (ISDB-T) with video encoded with MPEG-4 AVC (H.264) and audio with HE-AAC ([2]). Other countries in South America are following Brazil adopting ISDB-T with H.264 and HE-AAC.
[edit] Transmission
The various flavors of ISDB differ mainly in the modulations used, due to the requirements of different frequency bands. The 12 GHz band ISDB-S uses PSK modulation, 2.6 GHz band digital sound broadcasting uses CDM and ISDB-T (in VHF and/or UHF band) uses COFDM with PSK/QAM.
[edit] Interaction
Besides audio and video transmission, ISDB also defines data connections (Data broadcasting) with the internet as a return channel over several media (10Base-T/100Base-T, Telephone line modem, Mobile phone, Wireless LAN (IEEE 802.11) etc.) and with different protocols. This is used, for example, for interactive interfaces like data broadcasting (ARIB STD B-24) and electronic program guides (EPG).
[edit] Interfaces and Encryption
The ISDB specification describes a lot of (network) interfaces, but most importantly the Common Interface for Conditional Access (ARIB STD-B25) with the Common Scrambling Algorithm (CAS) system called MULTI2 required for (de-)scrambling television.
The ISDB CAS system is operated by a company named B-CAS in Japan; the CAS card is called B-CAS card. The Japanese ISDB signal is always encrypted by the B-CAS system even if it is a free television program. That is why it is commonly called "Pay per view system without charge".[citation needed] An interface for mobile reception is under consideration.[citation needed]
ISDB supports RMP (Rights management and protection). Since all digitial television (DTV) systems carry digital data content, a DVD or high-definition (HD) recorder could easily copy content losslessly. Hollywood[who?] requested copy protection; this was the main reason for RMP being mandated. The content has three modes: “copy once”, “copy free” and “copy never”. In “copy once” mode, a program can be stored on a hard disc recorder, but cannot be further copied; only moved to another copy-protected media—and this move operation will mark the content “copy one generation”, which is mandated to permanently prevent further copying. “Copy never” programming may only be timeshifted and cannot be permanently stored. Currently[when?], the Japanese government is evaluating using the Digital Transmission Content Protection (DTCP) "Encryption plus Non-Assertion" mechanism, to allow making multiple copies of digital content between compliant devices[3
integrated Services Digital Broadcasting (ISDB) is a Japanese standard for digital television (DTV) and digital radio used by the country's radio and television stations. ISDB replaced the previously used MUSE "Hi-vision" analogue HDTV system.
ISDB is maintained by the Japanese organization ARIB. The standards can be obtained for free at the Japanese organization DiBEG website and at ARIB.
The core standards of ISDB are ISDB-S (satellite television), ISDB-T(terrestrial), ISDB-C (cable) and 2.6GHz band mobile broadcasting which are all based on MPEG-2 video and audio coding as well as the transport stream described by the MPEG-2 standard, and are capable of high definition television (HDTV). ISDB-T and ISDB-Tsb are for mobile reception in TV bands. 1seg is the name of an ISDB-T service for reception on cell phones, laptop computers and vehicles.
The concept was named for its similarity to ISDN, because both allow multiple channels of data to be transmitted together (a process called multiplexing). This is also much like another digital radio system, Eureka 147, which calls each group of stations on a transmitter an ensemble; this is very much like the multi-channel digital TV standard DVB-T. ISDB-T operates on unused TV channels, an approach taken by other countries for TV but never before for radio.
Video and audio compression
ISDB has adopted the MPEG-2 video and audio compression system. ATSC and DVB also adopted the same system. DVB and ISDB also provide for other video compression methods to be used, including JPEG and MPEG-4, although JPEG is only a required part of the MHEG standard. Brazil is using ISDB for terrestrial broadcasting (ISDB-T) with video encoded with MPEG-4 AVC (H.264) and audio with HE-AAC ([2]). Other countries in South America are following Brazil adopting ISDB-T with H.264 and HE-AAC.
[edit] Transmission
The various flavors of ISDB differ mainly in the modulations used, due to the requirements of different frequency bands. The 12 GHz band ISDB-S uses PSK modulation, 2.6 GHz band digital sound broadcasting uses CDM and ISDB-T (in VHF and/or UHF band) uses COFDM with PSK/QAM.
[edit] Interaction
Besides audio and video transmission, ISDB also defines data connections (Data broadcasting) with the internet as a return channel over several media (10Base-T/100Base-T, Telephone line modem, Mobile phone, Wireless LAN (IEEE 802.11) etc.) and with different protocols. This is used, for example, for interactive interfaces like data broadcasting (ARIB STD B-24) and electronic program guides (EPG).
[edit] Interfaces and Encryption
The ISDB specification describes a lot of (network) interfaces, but most importantly the Common Interface for Conditional Access (ARIB STD-B25) with the Common Scrambling Algorithm (CAS) system called MULTI2 required for (de-)scrambling television.
The ISDB CAS system is operated by a company named B-CAS in Japan; the CAS card is called B-CAS card. The Japanese ISDB signal is always encrypted by the B-CAS system even if it is a free television program. That is why it is commonly called "Pay per view system without charge".[citation needed] An interface for mobile reception is under consideration.[citation needed]
ISDB supports RMP (Rights management and protection). Since all digitial television (DTV) systems carry digital data content, a DVD or high-definition (HD) recorder could easily copy content losslessly. Hollywood[who?] requested copy protection; this was the main reason for RMP being mandated. The content has three modes: “copy once”, “copy free” and “copy never”. In “copy once” mode, a program can be stored on a hard disc recorder, but cannot be further copied; only moved to another copy-protected media—and this move operation will mark the content “copy one generation”, which is mandated to permanently prevent further copying. “Copy never” programming may only be timeshifted and cannot be permanently stored. Currently[when?], the Japanese government is evaluating using the Digital Transmission Content Protection (DTCP) "Encryption plus Non-Assertion" mechanism, to allow making multiple copies of digital content between compliant devices[3
IRD
An integrated receiver/decoder (IRD) is an electronic device used to pick-up a radio-frequency signal and convert digital information transmitted in it.
Consumer IRDs commonly called a set-top box are used by end users and are much cheaper compared to professional IRDs. To curb content piracy, they also lack many features and interfaces found in professional IRDs such as outputting uncompressed SDI video or ASI transport stream dumps. They are also designed to be more aesthetically pleasing.
PID
Commonly found in radio, television, Cable and satellite broadcasting facilities, the IRD is generally used for the reception of contribution feeds that are intended for re-broadcasting. The IRD is the interface between a receiving satellite dish or Telco networks and a broadcasting facility video/audio infrastructure.
Professional IRDs have various features that consumer IRDs lack such as:
SDI outputs.
ASI inputs / outputs.
AES/EBU Audio decoding.
VBI reinsertion.
WSS data and pass through.
Transport stream demultiplexing.
Genlock input.
Frame synchronization of digital video output to analogue input.
Closed captions and VITS/ITS/VITC Insertion.
Video test pattern generator.
Remote management over LAN/WAN.
GPI interface - For sending external alarm triggers.
Rack mountable.
An integrated receiver/decoder (IRD) is an electronic device used to pick-up a radio-frequency signal and convert digital information transmitted in it.
Consumer IRDs commonly called a set-top box are used by end users and are much cheaper compared to professional IRDs. To curb content piracy, they also lack many features and interfaces found in professional IRDs such as outputting uncompressed SDI video or ASI transport stream dumps. They are also designed to be more aesthetically pleasing.
PID
Commonly found in radio, television, Cable and satellite broadcasting facilities, the IRD is generally used for the reception of contribution feeds that are intended for re-broadcasting. The IRD is the interface between a receiving satellite dish or Telco networks and a broadcasting facility video/audio infrastructure.
Professional IRDs have various features that consumer IRDs lack such as:
SDI outputs.
ASI inputs / outputs.
AES/EBU Audio decoding.
VBI reinsertion.
WSS data and pass through.
Transport stream demultiplexing.
Genlock input.
Frame synchronization of digital video output to analogue input.
Closed captions and VITS/ITS/VITC Insertion.
Video test pattern generator.
Remote management over LAN/WAN.
GPI interface - For sending external alarm triggers.
Rack mountable.
IRD
An integrated receiver/decoder (IRD) is an electronic device used to pick-up a radio-frequency signal and convert digital information transmitted in it.
Consumer IRDs commonly called a set-top box are used by end users and are much cheaper compared to professional IRDs. To curb content piracy, they also lack many features and interfaces found in professional IRDs such as outputting uncompressed SDI video or ASI transport stream dumps. They are also designed to be more aesthetically pleasing.
An integrated receiver/decoder (IRD) is an electronic device used to pick-up a radio-frequency signal and convert digital information transmitted in it.
Consumer IRDs commonly called a set-top box are used by end users and are much cheaper compared to professional IRDs. To curb content piracy, they also lack many features and interfaces found in professional IRDs such as outputting uncompressed SDI video or ASI transport stream dumps. They are also designed to be more aesthetically pleasing.
cable
is two or more wires or ropes running side by side and bonded, twisted or braided together to form a single assembly. In mechanics, cables are used for lifting and hauling; in electricity they are used to carry electrical currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. Mechanical cable is more specifically called wire rope.
Electric cables discussed here are mainly meant for installation in buildings and industrial sites. For power transmission at distances from some km's to 600 km see high voltage cable, power cables and HVDC
Cable television is a system of providing television to consumers via radio frequency signals transmitted to televisions through fixed optical fibers or coaxial cables as opposed to the over-the-air method used in traditional television broadcasting (via radio waves) in which a television antenna is required. FM radio programming, high-speed Internet, telephony, and similar non-television services may also be provided.
The abbreviation CATV is often used to mean "Cable TV". It originally stood for Community Antenna Television, from cable television's origins in 1948: in areas where over-the-air reception was limited by distance from tranmitters or mountainous terrain, large "community antennas" were constructed, and cable was run from them to individual homes.
It is most commonplace in North America, Europe, Australia and East Asia, though it is present in many other countries, mainly in South America and the Middle East. Cable TV has had little success in Africa, as it is not cost-effective to lay cables in sparsely populated areas. So-called "wireless cable" or microwave-based systems are used instead.
is two or more wires or ropes running side by side and bonded, twisted or braided together to form a single assembly. In mechanics, cables are used for lifting and hauling; in electricity they are used to carry electrical currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. Mechanical cable is more specifically called wire rope.
Electric cables discussed here are mainly meant for installation in buildings and industrial sites. For power transmission at distances from some km's to 600 km see high voltage cable, power cables and HVDC
Cable television is a system of providing television to consumers via radio frequency signals transmitted to televisions through fixed optical fibers or coaxial cables as opposed to the over-the-air method used in traditional television broadcasting (via radio waves) in which a television antenna is required. FM radio programming, high-speed Internet, telephony, and similar non-television services may also be provided.
The abbreviation CATV is often used to mean "Cable TV". It originally stood for Community Antenna Television, from cable television's origins in 1948: in areas where over-the-air reception was limited by distance from tranmitters or mountainous terrain, large "community antennas" were constructed, and cable was run from them to individual homes.
It is most commonplace in North America, Europe, Australia and East Asia, though it is present in many other countries, mainly in South America and the Middle East. Cable TV has had little success in Africa, as it is not cost-effective to lay cables in sparsely populated areas. So-called "wireless cable" or microwave-based systems are used instead.
vtr
By the late 1990s videotape was familiar to most television viewers in developed countries. The videocassette was a central product throughout the home video market and in various formats was widely used as a consumer item for home recording. Despite these widespread and common uses, however, videotape is of relatively recent origin. Its immediate antecedent is, of course, audiotape.
The processes of recording audiotape and videotape work on the same principle. An audio or video recording head is a small electromagnet containing two coils of wires separated by a gap. An electrical current passing through the wires causes a magnetic charge to cross the gap. When tape, coated with metal particles, passes through the gap patterns are set on the material. On audiotape, each syllable, musical note, or sneeze sets down its own distinct pattern. For videotape, which carries several hundred times as much information as audiotape, each image has its own pattern. In 1951, engineers at Bing Crosby Enterprises demonstrated a black-and-white videotape recorder that used one-inch tape (tape size refers to tape width) running at 100 inches per second. At that rate a reel of tape three feet in diameter held about fifteen minutes of video. Crosby continued to fund the research, driven not only by a sense of commercial possibilities for videotape, but reportedly also by his wish to record television programs so that he could play golf without being restricted to live performances. Two years later RCA engineers developed a recorder which reproduced not only black-and-white but color pictures. However, tape ran past the heads at a blinding 360 inches per second, which is 20 miles per hour. Neither machine produced pictures of adequate quality for broadcast. It simply was not possible to produce a stable picture at such a high tape speed.
By the late 1990s videotape was familiar to most television viewers in developed countries. The videocassette was a central product throughout the home video market and in various formats was widely used as a consumer item for home recording. Despite these widespread and common uses, however, videotape is of relatively recent origin. Its immediate antecedent is, of course, audiotape.
The processes of recording audiotape and videotape work on the same principle. An audio or video recording head is a small electromagnet containing two coils of wires separated by a gap. An electrical current passing through the wires causes a magnetic charge to cross the gap. When tape, coated with metal particles, passes through the gap patterns are set on the material. On audiotape, each syllable, musical note, or sneeze sets down its own distinct pattern. For videotape, which carries several hundred times as much information as audiotape, each image has its own pattern. In 1951, engineers at Bing Crosby Enterprises demonstrated a black-and-white videotape recorder that used one-inch tape (tape size refers to tape width) running at 100 inches per second. At that rate a reel of tape three feet in diameter held about fifteen minutes of video. Crosby continued to fund the research, driven not only by a sense of commercial possibilities for videotape, but reportedly also by his wish to record television programs so that he could play golf without being restricted to live performances. Two years later RCA engineers developed a recorder which reproduced not only black-and-white but color pictures. However, tape ran past the heads at a blinding 360 inches per second, which is 20 miles per hour. Neither machine produced pictures of adequate quality for broadcast. It simply was not possible to produce a stable picture at such a high tape speed.
vtr.(video tape recorder)
a device for recording television programs on magnetic tape for delayed transmission or for storage.
Videotaping is similar to audiotape recording. The electronic impulses of television pictures (video signal) and sound (audio signal) are recorded on the videotape by magnetizing the iron oxide coating on the videotape. During playback, the recorded video and audio signals are converted again by the television set into television pictures and sounds. However, the amount of electronic information is many times greater for video than for audio recording.
vtr system
There are many different systems of treating and recording the video signals. Videotape recording systems can be divided roughly into three subsections: analog and digital; composite (Y/C), and component; and tape formats.
analog and digital system
Both analog and digital systems are used in naval imaging facilities. The analog system is easier to understand if you think of it in the same terms as a record and a phonograph. Analog systems record the continually fluctuating video signal that is created and processed by a video source (camera) on videotape.During playback, the recorded information is retrieved as an identical, continually fluctuating signal from the videotape.
a device for recording television programs on magnetic tape for delayed transmission or for storage.
Videotaping is similar to audiotape recording. The electronic impulses of television pictures (video signal) and sound (audio signal) are recorded on the videotape by magnetizing the iron oxide coating on the videotape. During playback, the recorded video and audio signals are converted again by the television set into television pictures and sounds. However, the amount of electronic information is many times greater for video than for audio recording.
vtr system
There are many different systems of treating and recording the video signals. Videotape recording systems can be divided roughly into three subsections: analog and digital; composite (Y/C), and component; and tape formats.
analog and digital system
Both analog and digital systems are used in naval imaging facilities. The analog system is easier to understand if you think of it in the same terms as a record and a phonograph. Analog systems record the continually fluctuating video signal that is created and processed by a video source (camera) on videotape.During playback, the recorded information is retrieved as an identical, continually fluctuating signal from the videotape.
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