In Broadcast - December 2020 - 48

www.inbroadcast.com | Vol: 10 - Issue 12 | InReview 2020

InUSA

With Millions Working Remotely,
2020 Was The Year
of The Codec
By
Michael Grotticelli...

eveloping and releasing new
codecs is hard work... both
technically and legally. Just ask the
people involved with MPEG's H.265/
HEVC, which provides efficiency gains
of 20-30 percent over H.264 but failed
to be embraced by the industry due to
patent-pools and licensing issues. This
created the need for a new codec to fill
the gap.
Enter not one but three new codecs,
which were all either standardized or
nearing this milestone in 2020.
Those new MPEG-5 codecs are:
Versatile Video Coding (VVC); dual
Essential Video Coding (EVC) profiles
(baseline and main) otherwise known
as MPEG-5 Part 1; and Low Complexity
Enhancement Video Coding (LCEVC),
aka, MPEG-5 Part 2.
In July, after several years of
research and standardization, the
Fraunhofer Heinrich Hertz Institute
announced the official release of the
H. 266/Versatile Video Coding (VVC)
spec. It was finalized by the Joint Video
Experts Team (JVET), a video expert
team of the MPEG working group of
ISO/IEC JTC 1 and the VCEG working
group of the ITU-T.
VVC offers the highest compression
efficiency of all video codecs and is
ideally suited to higher resolution
video streams due to its proprietary
coding tools, which can operate
on block sizes of up to 128x128
pixels - and with 64x64 sample
size transforms. VVC can achieve a
realistic reduction in bitrate of around
40 percent for existing HD and 4K
services deployed with HEVC, at the
same visual quality.
EVC, is an alternative to HEVC
(H.265/MPEG-H) and AVC (H.264/
MPEG-4 AVC), but with coding
efficiency similar to HEVC. It includes
two tool sets: a base and an enhanced
tool set. The base tool set is configured
with tools that were made public more
than 20 years ago. There are additional
tools in the enhanced tool set, each
of which provides a significant
improvement in coding efficiency
EVC was designed as a royaltyfree option for content producers

while also providing adequate tools
and algorithms to produce higher
quality video than the base tool set.
Curiously, the enhancement layer's
tools (also referred to as the Main
layer) are subject to royalties. Many
predict MPEG-5 EVC could become a
good solution for 4K content across a
multichannel video service provider
with hundreds of channels. The goal
of.
In October, the VC-6 - a new
VVC offers the highest compression efficiency of all video
codecs and is ideally suited to higher resolution video streams
standard authorised by the Society
of Motion Picture & TV Engineers
LCEVC-aware decoder (retrofitted via
(SMPTE) and LCEVC (MPEG-5 Part
software update or leveraging
2) a new standard was authorised
HTML5 scripts) puts the signal
by MPEG. VC-6 is an
back together again, while
AI-enhanced
codec
an LCEVC-unaware decoder
aimed at high-quality
can still decode the lower resolution
compression of still
base stream. This type of backward
and moving images.
compatibility can leverage the
It is optimized for
standard not just to improve the
intermediate, mezzanine LCEVC improves video compression efficiency while maintaining quality of streaming services, but
or contribution coding or lowering the overall encoding and decoding complexity
also to upgrade the resolution
applications
and
will
improve
On the encode side, you down- of broadcast services without much
performance (and storage) for editing, sample or separate the high increase in bandwidth and without
content contribution, live events, and frequencies (the image detail) from leaving any legacy decoder behind.
archiving.
the core signal, then you encode the
So far independent tests have shown
LCEVC leverages a base video core signal at a lower resolution with that if you're seeing 40-50 percent
codec (e.g., AVC, HEVC, AV1, EVC, a traditional codec. This technology bitrate reduction with H.265 today,
VVC etc.) and adds a low complexity is available in both hardware and applying LCEVC will give you another
enhancement that adds up to two software. Next you create the first 30 percent in bandwidth savings. And
layers of encoded residuals to level of correction, which is used whereas some compression suppliers
correct artifacts produced by the for correcting the impairments are touting the ability to deliver 4K
base video codec. It can also add generated by the base codec. Then video at 25-30 Mbps, LCEVC can do
detail and sharpness for the final there is a normative upsampling it at 12-15 Mbps. This includes live
output video. By doing so, it improves that operates as a sort of simplified encoding workflows, thanks to reduced
video compression efficiency while " super resolution " using a non-linear processing power requirements.
maintaining or lowering the overall cascade of parallel operations that is
At the end of the day, any of these
encoding and decoding complexity.
very fast. There are also the top-level new codecs offer the potential to
This is not to say that one is better details that cannot be predicted with preserve pristine video quality and
than the other. In fact, all of these a grade of upsampling, which are reduce
bandwidth
requirements
codecs show promise for real-time used to reconstruct true fidelity to the with the goal of improving user
contribution and live streaming. Time original. In addition, LCEVC improves engagement for service providers,
will tell which is embraced the most. the fidelity of dark scenes and helps to reducing storage requirements for
What they will do is help service reduce impairments such as banding.
editors and archives. And they can all
providers manage bandwidth and
On
the
decode
side,
the be deployed via a software upgrade.
handle spikes in live streaming traffic enhancement is received in a separate New deployments are happening
that typically occur with entertainment elementary stream multiplexed in SEI virtually every month, with more
and sports events online.
metadata or as a separate PID in a to come in 2021. The goal is to
It's said that LCEVC improves the transport stream. There are several significantly reduce the data rates
performance of all video codecs standard ways to distribute these of existing video services in order to
by being situated both around the signals, already supported by standard keep up with the ever increasing use of
encoder and behind the decoder in a workflows. Then at the receive end video by consumers.
transcoding ecosystem.
you have the de-muxing, where an
It's been a good year for encoding.

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