New Audio Approach Brings Clarity to NBA Draft

By Dan Daley
Glowpoint revamped the audio portion of its IP video system for the 2008 NBA Draft last week, helping the NBA coverage sound as clear as a bell. A Sony PCS-1 video conferencing system
used an h.264 encode of both the video signal and the audio using the medium-resolution AAC codec within the MPEG-4 standard. The
change in hardware for this year’s draft event was driven in part
by a pursuit of improved audio. Previously, the video conferencing system
utilized the G.711 protocol, a PCM scheme that operates at an 8-kHz
sampling rate and 64 kbps per channel. It was intended to be used with
telephone audio and its response range was limited to about 4 kHz. Switching
to the AAC codec allows for up to 48 full-bandwidth audio channels in
a single stream plus 15 LFE channels and 15 more with metadata. It can
send audio on a limited number of channels at up to 320 kbps. In a nutshell,
the sound has gone from telephone to iPhone (which also uses the AAC
codec). Dan
Boland, vice president of broadcast and digital media for Glowpoint, says that
while the increased quality of the new system configuration offers improved
audio quality, the faster throughput of the sound has another element
that further enhances the draft proceedings on television. “The reduced
latency of the audio between talent and interview subjects like analysts
and teams representatives when there is a two-up on the screen means
there’s no more awkward silence while the [interviewee] waits for
the sound to catch up,” he explains. “They can respond immediately,
so the viewer will get quick, emotional responses or be able to watch
their reaction as they ponder a tough question. It really adds to the
narrative of the proceedings and engages the audience.”
The
faster signal throughput for audio and video via IP also helps with
the increased number of live source locations – 15 this year, including
team cities like New York, Chicago and Charlotte, as well as ESPN’s
broadcast hub in Bristol, CT.