broadcast technology trends and insights 2015
Unified linear TV delivery
enabled by software-defined
video
UNIFYING TRADITIONAL AND
MULTI-SCREEN WORKFLOWS
As exciting new over-the-top
(OTT) and video-on-demand
(VoD) services offered by
traditional direct-to-home (DTH)
providers gain popularity, video
providers are able to quickly
scale up and introduce new
features thanks to the inherent
agility of software.
The software abstraction
of video processing functions
from underlying hardware
infrastructure allows encoders,
transcoders, origin servers and
multiplexers to be logically
configured as virtual modules
without the need for manual
cabling. Entire systems can
be managed and controlled
for network optimisation and
reliability through a unified
operator interface. New multi-
screen, live-to-VoD and targeted
advertising services can be
deployed alongside traditional
and new linear workflows
to further drive resource
management efficiencies.
Software-defined video
encoding, multiplexing and
system management can enable
operators to extract additional
capacity from their networks,
increase the QoS, and reliability
of linear TV delivery networks
through full system redundancy,
simplified workflows and
advanced configuration options.
Elemental video solutions can
integrate both linear and OTT
video delivery within a single
unified workflow. channels that need it most at any
point in time.
THE PROBLEM WITH STATIC
INFRASTRUCTURE
Most linear TV operations today
include legacy video processing
equipment dedicated to specific
tasks such as encoding, splicing
and multiplexing. Although these
workflows may perform well,
their functions remain tied to
specific hardware components,
many times all the way to the
chip level.
Today, support for content
distribution across most
traditional pay-TV networks
requires advanced compression
and statistical multiplexing
methodologies. Since QAM
bandwidth for delivering these
channels is fixed, one approach
to allocating bandwidth is to
simply divide the total available
bandwidth by the number of
sub-channels and then evenly
allocate constant bitrate (CBR)
encoding levels.
However, this static allocation
method is extremely inefficient
as bandwidth is equally spread
across simple and more complex
video scenes.
Instead, a more efficient
method is to pool together the
available bandwidth for several
sub-channels and apply active
variable bitrate (VBR) encoding
per sub-channel in order to
increase overall picture quality
and free up bandwidth for the THE FLEXIBILITY OF A
SOFTWARE APPROACH
Software-defined video solutions
are in part differentiated by the
ability to migrate changes and
improvements among different
codecs such as MPEG-2 and
H.264. This is not possible with
hardware-based solutions for
video compression.
For more aggressive unified
headend strategies, encoders
can ingest 4K/Ultra HD (UHD)
or HD content and transcode it
into parallel HEVC/H.265 4K/
UHD and MPEG-2 or H.264
HD and SD streams, allowing a
single system to create multi-
resolution channel outputs from
a single source. Whatever the
codec combination, an optimal
linear video delivery solution is
designed to adapt and grow
with rapidly evolving cable,
satellite and terrestrial network
requirements.
At a high level, multi-
screen video delivery requires
encoding, content protection
and monetisation in terms very
similar to traditional pay-TV
requirements. Encoding functions
differ in the ways metadata is
handled and in the types and
number of outputs required, but
input, redundancy and reliability
requirements are similar.
Down in the details, however,
many parts of the two delivery
Elemental Statmux allows simultaneous muxing for
Ultra HD, HD and SD.
18
www. a pb- n ews .co m
Keith Wymbs
Chief Marketing Officer
Elemental Technologies
workflows are significantly
different, with alternate
technologies for encryption,
alternate delivery protocols
and many different types of
metadata. Adding to these
differences is the frantic pace
of change driven by a heavy
dependence on consumer
devices that are typically updated
yearly and delivery standards
updating roughly every six
months.
Support for multi-screen video
delivery requires software-based
solutions that are nimble enough
to accommodate rapid change
while maintaining the reliability
required for 24/7 services. The
evolution of streaming protocols
and monetisation strategies for
OTT services generally requires
an advanced origin server, such
as Elemental Delta, to perform
just-in-time packaging, streaming
and digital rights management
(DRM).
Through an advanced
origin solution, content can
be encoded once, stored in a
deliverable mezzanine format,
and repackaged and encrypted
uniquely for new devices and
evolving customer expectations.
For a 24/7 service, regardless
of the deployment model or
workflow, the possibility of failure
at any point in the signal path
needs to be well understood,
with counter measures in place to
provide the shortest interruption
possible. All of this experience
can also be applied to traditional
video operations where the pace
of change needs to match that of
disruptive multi-screen services.
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