Page 131 - ITU Journal, ICT Discoveries, Volume 3, No. 1, June 2020 Special issue: The future of video and immersive media

ITU Journal: ICT Discoveries, Vol. 3(1), June 2020

OVERVIEW OF MPEG-5 PART 2 –
LOW COMPLEXITY ENHANCEMENT VIDEO CODING (LCEVC)

Florian Maurer , Stefano Battista , Lorenzo Ciccarelli , Guido Meardi , Simone Ferrara
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1 RWTH Aachen University, Germany, Università Politecnica delle Marche (UNIVPM), Italy, V-Nova, UK

Abstract – This paper provides an overview of MPEG-5 Part 2 Low Complexity Enhancement Video Coding
(LCEVC), a novel video coding standard from the MPEG ISO Working Group. The codec is designed for use in
conjunction with existing video codecs, leveraging specific tools for encoding "residuals", i.e. the difference
between the original video and its compressed representation. LCEVC can improve compression efficiency
and reduce the overall computational complexity using a small number of specialized enhancement tools.
This paper provides an outline of the coding structure of encoder and decoder, coding tools, and an overview
of the performance of LCEVC with regard to both compression efficiency and processing complexity.

Keywords – Low Complexity Enhancement Video Coding (LCEVC), MPEG-5 Part 2, multi-resolution video
coding, video compression.

1. INTRODUCTION is the case, changing codecs cannot be done without
relevant up-front investments and large amounts of
This paper provides an overview of MPEG-5 Part 2 time. Accordingly, having the possibility to upgrade
Low Complexity Enhancement Video Coding an ecosystem without the need to replace it
(LCEVC), a new video coding standard developed by completely and still having the freedom to select a
MPEG that is scheduled to be published as base codec of their choice is an important option
ISO/IEC 23094-2 [1]. that operators need to have.
Rather than being a replacement for existing video Further, service operators, small and big alike, are
coding schemes, LCEVC is designed to leverage increasingly concerned about the cost of delivering
existing (and future) codecs to enhance their a growing number of services, often using
performances whilst reducing their computational decentralized infrastructures such as cloud-based
complexity. It is not meant to be an alternative to systems or battery-powered edge devices. The need
other codecs, but rather a useful complement to any to increase the overall efficiency of video delivery
codec.
systems must also be balanced with the seemingly
This is achieved by a combination of processing an conflicting needs to upgrade video resolutions and
input video at a lower resolution with an existing consume less power.
single-layer codec and using a simple and small set Finally, the “softwarization” of solutions across the
of highly specialized tools to correct impairments, technological spectrum has brought up the need to
upscale and add details to the processed video. have also codec solutions which do not necessarily
require a bespoke dedicated hardware for
2. COMMERCIAL REASONS FOR THE operating efficiently, but rather can operate as a
STANDARD software layer on top of existing infrastructures and

LCEVC was driven by several commercial needs put deliver the required performances.
forward to MPEG by many leading industry experts LCEVC seeks to solve the above issues by providing
from various areas of the video delivery chain, from a solution that is compatible with existing
vendors to traditional broadcasters, from satellite (and future) ecosystems whilst delivering it at a
providers to over-the-top (OTT) service providers lower computational cost than it would be
and social media [2]. otherwise possible with a tout-court upgrade.
Service providers work with complex ecosystems. Aside from rapidly improving the efficiency of
They make choices on codecs based on various legacy workflows, LCEVC can also improve the
factors, including maximum compatibility with business case for the adoption of next-generation
their existing ecosystems, costs of deploying the codecs, by combining their superior coding
technology (including royalty rates), etc. Sometimes efficiency with significantly lower processing
they are forced to make certain choices. Whichever requirements.

© International Telecommunication Union, 2020 109