In Broadcast - April 2020 - 56

56

www.inbroadcast.com | Vol: 10 - Issue 4 | April 2020

InMedia

Encode/Decode - Bits per Buck
Video compression, live or file-based, is all about generating the most cost
efficient and high quality final picture to increasingly discerning viewers
Contributing Editor Adrian Pennington investigates...

W

hile H.264/AVC continues to
be a pillar of online streaming,
as the most used video codec in
2019 according to survey data from
Bitmovin, the market is shifting to
MPEG successor H.265 / HEVC and
planning to implement the similarly
performing
non-MPEG
standard
AV1 both which roughly double the
compression efficiency for the same
bit rate.
Matters are moving at pace in AV
streaming standards not least because
of huge acceleration in demand for
delivering more volume at greater
quality and at lower cost.
Two new standards are due
to be ratified by MPEG later
this year which go some way to
address this.
MPEG-5
Essential
Video
Coding / EVC will have roughly
the same performance as HEVC.
It will be offered in a royalty
free baseline version, using
patent licences which have
expired, and in a version which offers
more advanced features which users
can choose to pay for or not.
EVC
will
require
hardware
implementation is likely to take at
least a couple of years for initial
adoption to take hold in devices
including TV sets and smartphones.
Low Complexity Video Coding is a
software addition for any codec (AVC,
HEVC, EVC, or in future, VVC) which is
designed to improve the performance
of underlying hardware encoder. This
solution is based on V-Nova's Perseus
Plus compression tech and makes it
a cheaper alternative for companies
than ripping and replacing devices in
the field.

A patent pool for this along
with costs (i.e. €0.24 for display
devices including smartphones
- which is a lot when you tot up
how many iPhones Apple sells)
has been announced but the
Alliance has yet to respond.

Versatile Video Codec is the nextgen codec from MPEG targeting
immersive media applications like VR
and 8K. This will also require hardware
implementations and there is no word
yet on cost, expect that it will be
licensed and everyone is keen to avoid
a repeat of the opaque patent pool
administration of HEVC.
Sticking with standards and usage
costs, the instigators of AV1, Alliance
for Open Media which includes all the
members of FAANG had previously
declared the codec to be licence free.
That is being challenged by companies
including Philips, Ericsson Dolby and
Orange who state that AV1 contains
some of their patented developments.
What is the best way of delivering
8K content such as Insight TV's
Endurance 24 Hours of Spa?

Powered by AI
It's likely that the traditional
methodology
to
optimising
video streaming workflows has run its
course. Future advances will be made
in software and automated by AI.
One of the important ways that AI
can do this is by calculating bitrate
to optimise bandwidth usage while
maintaining an appropriate level of
quality. This is something that simply
cannot be done by hand; there is too
much information to process in the
time before network conditions change
again.
The video streaming world is also
looking at content-aware encoding
(CAE) in which an algorithm can
understand what kind of content is
being streamed, and optimise bitrate,
latency, and protocols, accordingly, for
use in both live and VOD workflows.
Haivision
Lightflow
Encode,
for
example,
uses
proprietary
machine
learning
to
make
smart
analysis
of
video content (per
title or per scene), to
determine the optimal
bitrate
ladder
and
encoding configuration
for each video. It uses
a video quality metric called

LQI which represents how good the
human visual system perceives video
content at different bitrates and
resolutions. Haivision claims this
results in significant bitrate reductions
and perceptual quality improvements,
ensuring that an optimised cost-quality
value is realised.
Harmonic's
software-based
Electra XOS live video processor is
another example and it being used
by Australian SVOD Foxtel to deliver
UHD programming within existing
bandwidth constraints. This features
EyeQ content-aware technology (see
what they did there?), which aims to
reduce OTT delivery costs and improve
viewer experiences.
Harmonic also uses CAE and has
conducted tests, including of an 8K
broadcast with BT Sport of a Rugby 7s
match late last year, which validates
that CAE efficiency depends on content
complexity. Indeed, its CAE tests on 8K
live streaming is claimed to match the
efficiency of that promised by VVC in
2022, "proving that we can use today's
technology to deliver tomorrow's
content, and without burning the
budget," says Thierry Fautier, VP of
Video Strategy at Harmonic.
"8K is now being delivered with
technology that was developed almost
three years ago. Operators want more
affordable bit rates, with a goal to
come close to what is currently used
for 4K OTT streaming (a 25 Mbps
connection is required for Netflix in
HDR). We have demonstrated that it is
now possible with a range of 14 Mbps
to 39 Mbps, without any optimisation
done for 8K, using cloud-powered
encoding and CAE technology."
iSize Technologies has developed
BitSave v.2 for the perceptual
optimisation of video prior to
encoding. What this means is that the
AI optimises video frames before the
video is actually compressed. This
'precoder' enhances details of the
areas of each frame that affect the
perceptual quality score of the
Harmonic Electra XOS
http://www.inbroadcast.com https://www.v-nova.com/ https://www.v-nova.com/ https://netinsight.net/ https://www.harmonicinc.com https://www.harmonicinc.com https://www.harmonicinc.com
In Broadcast - April 2020

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