BBC Turns To Dirac Pro To Navigate HD In Beijing

By Carolyn Braff
Producing sports
in HD is nothing new for the BBC Network, but taking that HD production across
the globe to China
has created some issues as the countdown to the Opening Ceremonies continues. The
BBC’s technical team, however, is up to the task and has found multiple
solutions to the problems posed by large-scale HD production.
“The HD
aspect isn’t new to us, but in terms of the impact of HD, the two things that
cause the biggest headaches are cable runs and audio,” explains Charlie Cope,
lead editor and technical consultant for BBC post production. “We’ve had to put
an awful lot of extra fiber to deal with the length of cable runs, but the most
complex thing is the audio.”
Cope
explained that while a high definition video feed is relatively simple, the
audio tends to complicate matters in terms of how to allocate audio tracks to
different operations. The audio distribution from the host broadcaster is in
5.1 and while the BBC does not have to spend money to decode and encode it, the
network does need to provide a stereo option for its news division.
“You have
to be a bit inventive in how you manage that,” Cope says.
Another
issue is a lack of high definition circuits.
“We have a
lot of aspirations to deliver the venues in HD, but we only have SD circuits
booked,” Cope explains. To get around that, the BBC is experimenting with Dirac
Pro, which allows HD to be carried on an uncompressed SD circuit using motion
compensated wavelet coding.
“It can
bring an HD feed back into the IBC, but there are monitoring issues, since you
can’t pick out problems on a monitor from a scrambled signal,” Cope says.
The BBC is
also splitting its environment, relying on a Split Remote Concept to send the
feed to London for editing before transmitting the final version from Beijing,
which can create further sound issues.
“The
latency between London and Beijing
is 380 milliseconds, so that’s one of the big challenges is how you deal with
that,” Adams explains. “Worst case scenario,
it gets delivered back in SD and upconverted.”