Programming Metadata Communication Protocol
Encyclopedia
Programming Metadata Communication Protocol (PMCP) is a standard for use within digital television
broadcast facilities for transfer of the source data used to generate electronic program guide
listings and other program-related information. The resulting data may then be sent to a PSIP generator for conversion to broadcast-ready format.
PMCP is an XML-based platform-independent protocol for the exchange of data, which may then be transported between systems in a variety of forms such as files, messages, web or e-mail services.
(EPG). The data which populates the EPG comes from the ATSC's Program and System Information Protocol
(PSIP). PMCP provides the source data for PSIP, including which programs are airing on which channel, at which time. It also includes a great deal of extended data, including a synopsis of the program, year of production, V-Chip rating data, closed captioning indication, etc.
PMCP, defined in the Advanced Television Systems Committee's A/76B, provides ATSC broadcasters with a standardized means to exchange system information (SI) among systems that create and manage these data elements. These systems can be outside Program listing services, program management systems, traffic (commercial and program scheduling) and broadcast automation systems, which all contribute a portion of the PSIP data to a PSIP Generator.
PMCP data can be used to create MPEG-2
Program Specific Information (PSI, generally Program Association and Program Map Tables) mostly useful to receiving devices and PSIP, the Program and System Information Protocol, published as ATSC A/65, which generally includes program and channel guides which are useful for viewers deciding which television program to watch. Although most ATSC users are terrestrial broadcasters, PMCP includes the capability to specify information used in cable and satellite-delivered ATSC transports.
At the heart of PMCP is an XML
Schema (actually a collection of XML Schema Definition files), which provide a standardized structure into which PSI and PSIP-related data may be exchanged. PMCP does not dictate systems' internal database structures; it is simply a platform-independent protocol for the exchange of data.
PMCP may be transported between systems in a variety of forms. It may be exchanged as files, messages, or web services. Nothing in the specification would prevent the exchange of PMCP messages using simple email.
PMCP's development is managed by the ATSC's TSG/S1 group, which meets as needed, and reports to the Technology and Standards Group within the ATSC. It is an open, due process group, with a diverse membership, which during the heydey of PMCP development, numbered in the dozens.
PMCP was first published as A/76 in November 2004, and enjoys adoption from a variety of broadcast equipment and system vendors. Two revisions (largely backwards-compatible) with the standard have been made. ATSC A/76a extended PMCP to include metadata necessary for proper signaling of ACAP data broadcast elements, and A/76B, was released in 2007, fixed some errors and made the schema usable with the related SMPTE S2021 (BXF) schema.
Digital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...
broadcast facilities for transfer of the source data used to generate electronic program guide
Electronic program guide
Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming...
listings and other program-related information. The resulting data may then be sent to a PSIP generator for conversion to broadcast-ready format.
PMCP is an XML-based platform-independent protocol for the exchange of data, which may then be transported between systems in a variety of forms such as files, messages, web or e-mail services.
Standards
The Programming Metadata Communication Protocol (PMCP) is critical to viewers of digital television in the United States and other ATSC countries. When viewing digital television channels, people have become accustomed to navigating between channels via an electronic program guideElectronic program guide
Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming...
(EPG). The data which populates the EPG comes from the ATSC's Program and System Information Protocol
Program and System Information Protocol
The Program and System Information Protocol is the protocol used in the ATSC digital television system for carrying metadata about each channel in the broadcast MPEG transport stream of a TV station and for publishing information about television programs so that viewers can select what to watch...
(PSIP). PMCP provides the source data for PSIP, including which programs are airing on which channel, at which time. It also includes a great deal of extended data, including a synopsis of the program, year of production, V-Chip rating data, closed captioning indication, etc.
PMCP, defined in the Advanced Television Systems Committee's A/76B, provides ATSC broadcasters with a standardized means to exchange system information (SI) among systems that create and manage these data elements. These systems can be outside Program listing services, program management systems, traffic (commercial and program scheduling) and broadcast automation systems, which all contribute a portion of the PSIP data to a PSIP Generator.
PMCP data can be used to create MPEG-2
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...
Program Specific Information (PSI, generally Program Association and Program Map Tables) mostly useful to receiving devices and PSIP, the Program and System Information Protocol, published as ATSC A/65, which generally includes program and channel guides which are useful for viewers deciding which television program to watch. Although most ATSC users are terrestrial broadcasters, PMCP includes the capability to specify information used in cable and satellite-delivered ATSC transports.
At the heart of PMCP is an XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
Schema (actually a collection of XML Schema Definition files), which provide a standardized structure into which PSI and PSIP-related data may be exchanged. PMCP does not dictate systems' internal database structures; it is simply a platform-independent protocol for the exchange of data.
PMCP may be transported between systems in a variety of forms. It may be exchanged as files, messages, or web services. Nothing in the specification would prevent the exchange of PMCP messages using simple email.
PMCP's development is managed by the ATSC's TSG/S1 group, which meets as needed, and reports to the Technology and Standards Group within the ATSC. It is an open, due process group, with a diverse membership, which during the heydey of PMCP development, numbered in the dozens.
PMCP was first published as A/76 in November 2004, and enjoys adoption from a variety of broadcast equipment and system vendors. Two revisions (largely backwards-compatible) with the standard have been made. ATSC A/76a extended PMCP to include metadata necessary for proper signaling of ACAP data broadcast elements, and A/76B, was released in 2007, fixed some errors and made the schema usable with the related SMPTE S2021 (BXF) schema.