44 SMPTE Motion Imaging Journal
|
June 2018
1545-0279/18©2018SMPTE
TECHNICAL PAPER
broadcast delivery. Despite the progressively increasing
broadband bandwidths to subscribers, the cost of uni-
cast delivery to the online media delivery service pro-
viders of a large array of titles in ultrahigh-definition
(UHD) high dynamic range–wide color gamut neces-
sitates higher video compression. While the H.265/
High Efficiency Video Coding (HEVC) standard offers
an excess of 30% bit savings over the well-entrenched
H.264/Advanced Video Coding (AVC)
standard,
1
its adoption is mired in
unclear royalty payments to orga-
nizations with essential patents. In
September 2015, Alliance for Open
Media (AOM) embarked on develop-
ing a royalty-free standard achieves a
compression efficiency that far exceeds
that of H.265/HEVC.
2
The codebase
used as the starting point for develop-
ing the first version of the standard
was Google’s VP10 that had already
extended Google’s libvpx codec with
new coding tools.
3
Aspects from other
royalty-free codecs, such as Thor
4
and Daala,
5
were integrated into this
codebase. In addition, many new tools
have been experimentally integrated
into it. The tools are legally studied to
ensure that they are good candidates
for a royalty-free standard. As of April
2017, several of these tools that have
offered good compression gains without disproportion-
ate increase in decoding complexity have been enabled
by default, while the remaining experimental tools are
being refined. This paper presents an analysis of the
compression efficiency offered by the different tools in
the default set and in the experimental set. These are
compared against the popular open-source implementa-
tions of H.264, H.265, and VP9, namely, ×264, ×265,
and libvpx.
6–8
Though some comparison in this regard
has been done in Ref. 9, since newer tools have been
consolidated recently and conditions like intraperiod
are different, this analysis is expected to provide
different results.
Abstract
To achieve improved quality of service and efficiencies with
higher resolution, high dynamic range, and wide color gamut
in online media delivery, there is a need for advanced video
compression standards. Alliance for Open Media (AOM),
a joint development foundation, is targeting AOMedia
Video 1 (AV1) as a royalty-free video coding format that
is likely to be nalized before the end of 2017. Built on top
of Google’s VP9 codec, AV1 has brought
in new coding tools from other open source
royalty-free codecs. Multiple new royalty-
free coding tools have been contributed by
the members of AOM. In this paper, we
provide an analysis of the coding gains
offered by the default and experimental
tools in AV1 and the corresponding decod-
ing complexity increase for the over-the-
top adaptive bit-rate streaming delivery
use-cases. Also, the coding gains are com-
pared against the compression performance
of ×264, ×265, and libVP9 open-source
codecs to highlight the potential bit sav-
ings possible with AV1 using multiple
video quality metrics such as peak signal-
to-noise ratio, structure similarity, and
Netix’s Video Multi-Assessment Fusion
metric. These results indicate that AV1
offers competitive compression perfor-
mance over H.265 without signicantly
increasing the decoding complexity.
Keywords
Alliance for Open Media, compression efficiency, decoder
complexity, over-the-top video delivery, royalty-free, video
coding standards
Introduction
T
he ability to watch personalized content anytime
and anywhere at ever increasing resolution, frame
rate, and quality has resulted in online media
delivery gaining momentum over the traditional
Digital Object Identier 10.5594/JMI.2018.2821419
Date of publication: 1 June 2018
In this paper, we
provide an analysis
of the coding gains
offered by the
default and
experimental tools
in AV1 and the
corresponding
decoding
complexity
increase for the
over-the-top
adaptive bit-rate
streaming delivery
use-cases.
Analysis of the Emerging AOMedia AV1
Video Coding Format for OTT Use-Cases
By Sriram Sethuraman, Cherma Rajan, and Kaustubh Patankar
TECHNICAL PAPER
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