Link electronics Caption Encoder/Decoder SD SDI/Analog PTC-892, Инструкция по эксплуатации

Страница: 36 / 38

PTC-892 version 1 C 36
What are TSID and PSID?
What is TSID?
Transmission Signal Identifier (TSID) is a 16-bit packet contained within the
Extended Data Services (XDS) of the EIA-608B specification. Each television station is
assigned a unique TSID assigned by the FCC. The TSID code is inserted into the TV
Station video signal. The recent FCC mandate, states that the TSID ID packet must be
presented in the broadcast station’s NTSC signal if the station chooses to have PSIP
guide information.
The FCC has emphasized that when the NTSC channel is announced in PSIP,
the transmission of the NTSC TSID in line 21, field 2 (XDS Channel) of the NTSC
broadcast signal, is now mandatory.
In other words, to ensure proper operation of digital TV Sets, the TSID data
within the NTSC signal must be present. Digital TV Sets will compare the TSID
information in the PSIP with the TSID information in the NTSC broadcast signal,
verifying that the NTSC signal referenced in the PSIP is actually the desired signal.
What is PSIP?
The Program and Systems Information Protocol (PSIP) is the ATSC standard for
digital television channel naming, numbering and navigation. DTV Receivers use PSIP
information to tune and label digital and analog channels.
PSIP is data that is transmitted along with a station's DTV signal that tells DTV
receivers important information about the station and what is being broadcast. The most
important function of PSIP is to provide a method for DTV receivers to identify a DTV
station and to determine how a receiver can tune to it. PSIP identifies both the DTV
channel and the associated NTSC (analog) channel. It helps maintain the current
channel branding because DTV receivers will electronically associate the two channels
making it easy for viewers to tune to the DTV station even if they do not know the
channel number.
In addition to identifying the channel number, PSIP tells the receiver whether
multiple program channels are being broadcast and, if so, how to find them. It identifies
whether the programs are closed captioned, conveys V-chip information, if data is
associated with the program, and much more. If broadcasters do not include properly
encoded PSIP data in their DTV signals, receivers may not correctly identify and tune to
the station. Therefore, it is vital that all broadcasters understand PSIP and include the
data in their DTV stations signals. PSIP is a mandatory Advanced Television Systems
Committee (ATSC) Standard.