The DDC-3335 is part of a family of data transcoders
for converting between the commonly used MPEG2
Transport Stream formats in the broadcast industry
for video distribution.
The DDC-3335 accepts any ASI input data rate
within the range of 1.5 Mb/s to 50 Mb/s.
The DDC-3335 accepts either a 188 or 204 byte
packet format ASI signal. For a 188 byte packet ASI
input, Reed Solomon check bytes are automatically
added to convert the signal to a 204 byte packet
signal. For a 204 byte packet ASI input, existing RS
check bytes are over-written.
Interleaving and Energy Dispersal (Scrambling) of
the signal is also performed. These two functions may
be disabled by the insertion of on board links.
188 to 204 byte conversion & RS encoding are also
link enabled/disabled. Disabling 188 to 204 byte
conversion disables RS insertion and interleaving
automatically. |
Two ASI and 1 SPI outputs conforming to the DVB
standard are provided.
The addition of RS encoding and optional
Interleaving and Scrambling make the DDC-3335
suitable for preparing an ASI signal for transport over
Telecom type lines or, in conjunction with IRT's
MDT-3510 QPSK modulator, microwave links.
The signal is also monitored for MPEG2 transport
stream sync errors and provides front panel LED
indications for input packet byte length, loss of input
and loss of sync. Alarm relay contacts are also
provided on the rear connector for remote monitoring
of alarm status.
The DDC-3335 is fabricated in IRT's standard
Eurocard format and may be housed in a variety of
IRT Eurocard frames alongside other standard
modules. |
