October/November/December 2019 I 13
STREAMING VIDEO—AV CONTENT
DELIVERED OVER ETHERNET NETWORKS
AV content can be streamed over Ethernet LANs
and WANs, as well as the internet. This allows real-
time delivery of AV content, such as presentation
materials, videoconferencing, lectures, music, movies,
concerts, and sporting events. Often, this material can
be recorded and stored for later viewing on demand.
The Role of Video Compression
in Ethernet Transmission
The data rate of uncompressed digital video is too high
for delivery over Ethernet networks. Therefore, video
compression is employed. Video codecs—encoders/
decoders—compress and decompress the video bit stream
using various algorithms. The H.264/AAC codec is in
widespread use today. Just as it replaced its predecessors,
H.264/AAC will give way to more efficient codecs with
fewer design tradeoffs as 1080p HD video is overtaken by
4K UHD and beyond. The design tradeoffs that all codecs
seek to minimize involve a careful balance between image
quality, bit rate, and processing latency based on application
requirements. Streaming movies in 4K to large
displays requires the best image quality possible. In order
to achieve this higher quality, bit rate and latency are
sacrificed through use of more network bandwidth and
more complex processing. On an interactive link for con-
ferencing, low latency is paramount, so image quality and
bit rate are sacrificed. All codecs, including H.264/AAC,
rely on the following compression techniques to some
extent to achieve the tradeoffs described:
• Chrominance Subsampling—Chrominance
represents how much data in a pixel is allocated
to color. In chrominance subsampling, the video
signal is separated into a brightness channel and
two-color channels. The color channels are sampled
at a lower rate than the brightness. Color information
is decreased, but eyes are less sensitive
to color than to brightness, making the impact
barely noticeable.
The data rate of uncompressed
digital video is too high for
delivery over Ethernet networks.
Therefore, video compression
is employed.
BICSI EVENTS ARE HAPPENING ALL AROUND THE WORLD IN 2019
3rd Annual ACE Summit, Dubai, UAE....................................................................................................... 8 October
EMEA Saudi Arabia Tech Roadshow, Jeddah, Riyadh, Al Khobar, Saudi Arabia ...13, 15, 17 October
EMEA Italy Conference & Exhibition, Rome, Italy ............................................................................30 October
CALA Puerto Rico Conference & Exhibition, San Juan, Puerto Rico ....................................7 November
BICSI Day Greece, Athens, Greece ...........................................................................................................15 November
BICSI Day Korea, Seoul, Korea ..................................................................................................................15 November
BICSI Day Ecuador, Quito, Ecuador ........................................................................................................21 November
Japan Conference & Exhibition, Tokyo, Japan ................................................................................21 November
Southeast Asia Conference & Exhibition, Manila, Philippines ...................................... 25-26 November
South Pacific Australia Conference & Exhibition, Melbourne, Australia .................26-28 November
EMEA Tech Breakfast, Dubai, UAE ..........................................................................................................5 December
Speaking and sponsorship slots are available. Email global@bicsi.org or call Amy Slowik,
Global Events Supervisor, at +1 813.769.1844 for information. Visit bicsi.org/conferences
for details and the most up-to-date schedule.
/conferences
link