feature iptv
Software based
transmission
By John Wadle - VP for technology, OmniBus Systems.
T
he continued advance of IT system working reliably. A The technical challenges
within broadcast operations manufacturer’s update to the firmware
has transformed much of the of a single device can cause problems The challenges involved in delivering a
content acquisition and throughout the entire chain. With the scheduled transmission via a software-
management process into quantity and diversity of equipment
file-based workflows
The ability to
based solution, while providing the
involved, this is a complex and
same level of sophistication and
operating on IT servers and networks. move [the expensive system to maintain. reliability offered by specialised
One major exception to this trend,
transmission]
The costs of deploying and operating
broadcast hardware and automation
however, has been the transmission
process to a
such a full-featured transmission chain
systems, are substantial.
process - automated sequencing and
software-
for each channel can be prohibitive,
In 2004, OmniBus began a project to
playout - which remains dependent
based system
particularly for new players. This
develop a software-based transmission
upon specialised broadcast hardware. complexity and expense hinder the solution running on standard IT
For this process, transmission of a
on an IT
ability to launch new services.
hardware as an alternative to trad-
moderately complex channel can platform Facing this cost, some operators itional hardware transmission. The
involve a dozen or more specialised
provides a
resort to basic, ‘cuts only’ linear
objectives for this project included a
hardware components linked by an
new, cost-
playout using only a router and video
comprehensive set of features:
automation system. In many cases, the
effective
server. The resultant channels can
• Support for multiple video
costs associated with this traditional have an unprofessional look with no
approach to transmission are prohibitive
model for
compression formats, including MPEG
video or audio transitions and little or
2, MPEG 4/H.264, Windows
for IPTV operators intending to set up transmission no branding. Media/AV1, and DV25/50 with real-
and manage their own playout facilities.
operating as
This approach may have been
time encoding and decoding.
The ability to move this process to a
an extension
acceptable for new services in the past
• SD and HD channel transmission in
software-based system on an IT
of the IPTV IT
but now, with the fierce competition
both SDI and streaming video formats.
platform provides a new, cost-effective
infrastructure
for viewers, the creative elements of a
• Real-time up, down, and aspect ratio
model for transmission operating as an broadcast channel have become conversion.
extension of the IPTV IT infrastructure
already in
increasingly important. Sophisticated
• Real-time video & audio transition
already in place. place. programme presentation - with effects.
aesthetically pleasing transitions,
• Two-dimensional (2D) DVE moves for
It’s time for a change animated branding graphics, and picture-in-picture (squeezebacks).
creative promos between programmes
• Support for multiple audio tracks
To understand the details of this new - helps to differentiate one channel including Dolby 5.1 and PCM stereo.
model, let us first examine a traditional from another, builds brand identity and • Linear keying with in-out transition
‘transmission chain’ (See Figure 1). creates viewer loyalty. effects.
In Figure 1, each component of the For IPTV providers, the answer to • Animated graphics using GIFs or Targa
transmission chain is independently crafted, yet cost effective, transmission sequences.
controlled by the automation system lies in moving to an all-software solution • Character generator for creation of
using the unique protocol of each operating on a standard IT platform. text overlays.
device. During playout, a complex
interstitial sequence managed by
automation can require actions by six
or more broadcast devices, often with
dozens of control messages flowing
between automation and the devices
within a single video frame.
In addition to the complexity and
Right: Figure 1:
Typical broadcast
rigorous timing of such operations, an
transmission chain
overriding challenge is keeping such a
with automation.
28 l ibe l January/February 2009 l www.ibeweb.com
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