Instruction manual

HDE-3000 - 34 -
Caption Server
Caption Server is a device that sends caption data to another device like a MPEG
emission encoder. The HDE-3000 can be set up to be a caption server using one of the
two following protocols: The “Grand Alliance” protocol (SMPTE RP 2007) is a serial
communications protocol for transmitting caption data from a “caption server” to an
MPEG emission encoder. This protocol is sometimes referred to as “the old 19200
protocol” or “the push protocol”. The “SMPTE333” protocol (SMPTE 333M) is similar to
“grand alliance”, but SMPTE333 is more complex. The SMPTE333 protocol is
sometimes referred to as “the pull protocol”.
NOTE! IMPORTANT!
The required baud rate and format for SMPTE333
is 38400 baud and 8-none-1.
The required baud rate and format for Grand Alliance
is 19200 baud and 8-none-1.
You must manually select the correct baud rate and format for the selected protocol.
When using an HDE3000 as a “caption server”, it is necessary to turn off the open
caption decoder. In the menu “2.2 OPEN CAP DECODER SETUP MENU”, set both
items to “OFF”. Failure to turn off the open caption decoder will cause serial
communication problems between the HDE3000 and the MPEG emission encoder.
Using an HDE3000 as a “Caption Server”
A typical caption server is a relatively simple device that has only an SD video
input and a serial port. SD video containing line 21 EIA608 captions is fed to the
caption server, and it up-converts (or “transcodes”) the EIA608 caption to EIA708
and transmits the EIA608 and EIA708 captions to an MPEG encoder via serial
(SMPTE333).