The original blog post can be found at the Bitmovin Techblog and has been modified/updated here to focus on and highlight research aspects.

The 130th MPEG meeting concluded on April 24, 2020, in Alpbach, Austria … well, not exactly, unfortunately. The 130th MPEG meeting concluded on April 24, 2020, but not in Alpbach, Austria.

Because of the Covid-19 pandemic, the 130th MPEG meeting has been converted from a physical meeting to a fully online meeting, the first in MPEG’s 30+ years of history. Approximately 600 experts attending from 19 time zones worked in tens of Zoom meeting sessions supported by an online calendar and by collaborative tools that involved MPEG experts in both online and offline sessions. For example, input contributions had to be registered and uploaded ahead of the meeting to allow for efficient scheduling of two-hour meeting slots, which have been distributed from early morning to late night in order to accommodate experts working in different time zones as mentioned earlier. These input contributions have been then mapped to GitLab issues for offline discussions and the actual meeting slots have been primarily used for organizing the meeting, resolving conflicts, and making decisions including approving output documents. Although the productivity of the online meeting could not reach the level of regular face-to-face meetings, the results posted in the press release show that MPEG experts managed the challenge quite well, specifically

• MPEG ratifies MPEG-5 Essential Video Coding (EVC) standard;
• MPEG issues the Final Draft International Standards for parts 1, 2, 4, and 5 of MPEG-G 2nd edition;
• MPEG expands the coverage of ISO Base Media File Format (ISOBMFF) family of standards;
• A new standard for large scale client-specific streaming with MPEG-DASH;

Other Important Activities at the 130th MPEG meeting: (i) the carriage of visual volumetric video-based coding data, (ii) Network-Based Media Processing (NBMP) function templates, (iii) the conversion from MPEG-21 contracts to smart contracts, (iv) deep neural network-based video coding, (v) Low Complexity Enhancement Video Coding (LCEVC) reaching DIS stage, and (vi) a new level of the MPEG-4 Audio ALS Simple Profile for high-resolution audio among others

The corresponding press release of the 130th MPEG meeting can be found here: https://mpeg.chiariglione.org/meetings/130. This report focused on video coding (EVC) and systems aspects (file format, DASH).

MPEG ratifies MPEG-5 Essential Video Coding Standard

At its 130th meeting, MPEG announced the completion of the new ISO/IEC 23094-1 standard which is referred to as MPEG-5 Essential Video Coding (EVC) and has been promoted to Final Draft International Standard (FDIS) status. There is a constant demand for more efficient video coding technologies (e.g., due to the increased usage of video on the internet), but coding efficiency is not the only factor determining the industry’s choice of video coding technology for products and services. The EVC standard offers improved compression efficiency compared to existing video coding standards and is based on the statements of all contributors to the standard who have committed announcing their license terms for the MPEG-5 EVC standard no later than two years after the FDIS publication date.

The MPEG-5 EVC defines two important profiles, including “Baseline profile” and “Main profile”. The “Baseline Profile” contains only technologies that are older than 20 years or otherwise freely available for use in the standard. In addition, the “Main Profile” adds a small number of additional tools, each of which can be either cleanly disabled or switched to the corresponding baseline tool on an individual basis.

It will be interesting to see how EVC profiles (baseline and main) will find its path into products and services given the existing number of codecs already in use (e.g., AVC, HEVC, VP9, AV1) and those still under development but being close to ratification (e.g., VVC, LCEVC). That is, in total, we may end up with about seven video coding formats that probably need to be considered for future video products and services. In other words, the multi-codec scenario I have envisioned some time ago is becoming reality raising some interesting challenges to be addressed in the future.

Research aspects: as for all video coding standards, the most important research aspect is certainly coding efficiency. For EVC it might be also interesting to research its usability of the built-in tool switching mechanism within a practical setup. Furthermore, the multi-codec issue, the ratification of EVC adds another facet to the already existing video coding standards in use or/and under development.

MPEG expands the Coverage of ISO Base Media File Format (ISOBMFF) Family of Standards

At the 130th WG11 (MPEG) meeting, the ISOBMFF family of standards has been significantly amended with new tools and functionalities. The standards in question are as follows:

• ISO/IEC 14496-12: ISO Base Media File Format;
• ISO/IEC 14496-15: Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format;
• ISO/IEC 23008-12: Image File Format; and
• ISO /IEC 23001-16: Derived visual tracks in the ISO base media file format.

In particular, three new amendments to the ISOBMFF family have reached their final milestone, i.e., Final Draft Amendment (FDAM):

1. Amendment 4 to ISO/IEC 14496-12 (ISO Base Media File Format) allows the use of a more compact version of metadata for movie fragments;
2. Amendment 1 to ISO/IEC 14496-15 (Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format) adds support of HEVC slice segment data track and additional extractor types for HEVC such as track reference and track groups; and
3. Amendment 2 to ISO/IEC 23008-12 (Image File Format) adds support for more advanced features related to the storage of short image sequences such as burst and bracketing shots.

At the same time, new amendments have reached their first milestone, i.e., Committee Draft Amendment (CDAM):

1. Amendment 2 to ISO/IEC 14496-15 (Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format) extends its scope to newly developed video coding standards such as Essential Video Coding (EVC) and Versatile Video Coding (VVC); and
2. the first edition of ISO/IEC 23001-16 (Derived visual tracks in the ISO base media file format) allows a new type of visual track whose content can be dynamically generated at the time of presentation by applying some operations to the content in other tracks, such as crossfading over two tracks.

Both are expected to reach their final milestone in mid-2021.

Finally, the final text for the ISO/IEC 14496-12 6th edition Final Draft International Standard (FDIS) is now ready for the ballot after converting MP4RA to the Maintenance Agency. WG11 (MPEG) notes that Apple Inc. has been appointed as the Maintenance Agency and MPEG appreciates its valuable efforts for the many years while already acting as the official registration authority for the ISOBMFF family of standards, i.e., MP4RA (https://mp4ra.org/). The 6th edition of ISO/IEC 14496-12 is expected to be published by ISO by the end of this year.

Research aspects: the ISOBMFF family of standards basically offers certain tools and functionalities to satisfy the given use case requirements. The task of the multimedia systems research community could be to scientifically validate these tools and functionalities with respect to the use cases and maybe even beyond, e.g., try to adopt these tools and functionalities for novel applications and services.

A New Standard for Large Scale Client-specific Streaming with DASH

Historically, in ISO/IEC 23009 (Dynamic Adaptive Streaming over HTTP; DASH), every client has used the same Media Presentation Description (MPD) as it best serves the scalability of the service (e.g., for efficient cache efficiency in content delivery networks). However, there have been increasing requests from the industry to enable customized manifests for more personalized services. Consequently, MPEG has studied a solution to this problem without sacrificing scalability, and it has reached the first milestone of its standardization at the 130th MPEG meeting.

ISO/IEC 23009-8 adds a mechanism to the Media Presentation Description (MPD) to refer to another document, called Session-based Description (SBD), which allows per-session information. The DASH client can use this information (i.e., variables and their values) provided in the SBD to derive the URLs for HTTP GET requests. This standard is expected to reach its final milestone in mid-2021.

Research aspects: SBD’s goal is to enable personalization while maintaining scalability which calls for a tradeoff, i.e., which kind of information to put into the MPD and what should be conveyed within the SBD. This tradeoff per se could be considered already a research question that will be hopefully addressed in the near future.

An overview of the current status of MPEG-DASH can be found in the figure below.

The next MPEG meeting will be from June 29th to July 3rd and will be again an online meeting. I am looking forward to a productive AhG period and an online meeting later this year. I am sure that MPEG will further improve its online meeting capabilities and can certainly become a role model for other groups within ISO/IEC and probably also beyond.

The original blog post can be found at the Bitmovin Techblog and has been modified/updated here to focus on and highlight research aspects.

The 128th MPEG meeting concluded on October 11, 2019 in Geneva, Switzerland with the following topics:

• Low Complexity Enhancement Video Coding (LCEVC) Promoted to Committee Draft
• 2nd Edition of Omnidirectional Media Format (OMAF) has reached the first milestone
• Genomic Information Representation – Part 4 Reference Software and Part 5 Conformance Promoted to Draft International Standard

The corresponding press release of the 128th MPEG meeting can be found here: https://mpeg.chiariglione.org/meetings/128. In this report we will focus on video coding aspects (i.e., LCEVC) and immersive media applications (i.e., OMAF). At the end, we will provide an update related to adaptive streaming (i.e., DASH and CMAF).

Low Complexity Enhancement Video Coding

Low Complexity Enhancement Video Coding (LCEVC) has been promoted to committee draft (CD) which is the first milestone in the ISO/IEC standardization process. LCEVC is part two of MPEG-5 or ISO/IEC 23094-2 if you prefer the always easy-to-remember ISO codes. We introduced MPEG-5 already in previous posts and LCEVC is about a standardized video coding solution that leverages other video codecs in a manner that improves video compression efficiency while maintaining or lowering the overall encoding and decoding complexity.

The LCEVC standard uses a lightweight video codec to add up to two layers of encoded residuals. The aim of these layers is correcting artefacts produced by the base video codec and adding detail and sharpness for the final output video.

The target of this standard comprises software or hardware codecs with extra processing capabilities, e.g., mobile devices, set top boxes (STBs), and personal computer based decoders. Additional benefits are the reduction in implementation complexity or a corresponding expansion in spatial resolution.

LCEVC is based on existing codecs which allows for backwards-compatibility with existing deployments. Supporting LCEVC enables “softwareized” video coding allowing for release and deployment options known from software-based solutions which are well understood by software companies and, thus, opens new opportunities in improving and optimizing video-based services and applications.

Research aspects: in video coding, research efforts are mainly related to coding efficiency and complexity (as usual). However, as MPEG-5 basically adds a software layer on top of what is typically implemented in hardware, all kind of aspects related to software engineering could become an active area of research.

Omnidirectional Media Format

The scope of the Omnidirectional Media Format (OMAF) is about 360° video, images, audio and associated timed text and specifies (i) a coordinate system, (ii) projection and rectangular region-wise packing methods, (iii) storage of omnidirectional media and the associated metadata using ISOBMFF, (iv) encapsulation, signaling and streaming of omnidirectional media in DASH and MMT, and (v) media profiles and presentation profiles.

At this meeting, the second edition of OMAF (ISO/IEC 23090-2) has been promoted to committee draft (CD) which includes

• support of improved overlay of graphics or textual data on top of video,
• efficient signaling of videos structured in multiple sub parts,
• enabling more than one viewpoint, and
• new profiles supporting dynamic bitstream generation according to the viewport.

As for the first edition, OMAF includes encapsulation and signaling in ISOBMFF as well as streaming of omnidirectional media (DASH and MMT). It will reach its final milestone by the end of 2020.

360° video is certainly a vital use case towards a fully immersive media experience. Devices to capture and consume such content are becoming increasingly available and will probably contribute to the dissemination of this type of content. However, it is also understood that the complexity increases significantly, specifically with respect to large-scale, scalable deployments due to increased content volume/complexity, timing constraints (latency), and quality of experience issues.

Research aspects: understanding the increased complexity of 360° video or immersive media in general is certainly an important aspect to be addressed towards enabling applications and services in this domain. We may even start thinking that 360° video actually works (e.g., it’s possible to capture, upload to YouTube and consume it on many devices) but the devil is in the detail in order to handle this complexity in an efficient way to enable seamless and high quality of experience.

DASH and CMAF

The 4th edition of DASH (ISO/IEC 23009-1) will be published soon and MPEG is currently working towards a first amendment which will be about (i) CMAF support and (ii) event processing model. An overview of all DASH standards is depicted in the figure below, notably part one of MPEG-DASH referred to as media presentation description and segment formats.

The 2nd edition of the CMAF standard (ISO/IEC 23000-19) will become available very soon and MPEG is currently reviewing additional tools in the so-called technologies under considerations document as well as conducting various explorations. A working draft for additional media profiles is also under preparation.

Research aspects: with CMAF, low-latency supported is added to DASH-like applications and services. However, the implementation specifics are actually not defined in the standard and subject to competition (e.g., here). Interestingly, the Bitmovin video developer reports from both 2018 and 2019 highlight the need for low-latency solutions in this domain.

At the ACM Multimedia Conference 2019 in Nice, France I gave a tutorial entitled “A Journey towards Fully Immersive Media Access” which includes updates related to DASH and CMAF. The slides are available here.

Outlook 2020

Finally, let me try giving an outlook for 2020, not so much content-wise but events planned for 2020 that are highly relevant for this column:

• MPEG129, Jan 13-17, 2020, Brussels, Belgium
• DCC 2020, Mar 24-27, 2020, Snowbird, UT, USA
• MPEG130, Apr 20-24, 2020, Alpbach, Austria
• NAB 2020, Apr 08-22, Las Vegas, NV, USA
• ICASSP 2020, May 4-8, 2020, Barcelona, Spain
• QoMEX 2020, May 26-28, 2020, Athlone, Ireland
• MMSys 2020, Jun 8-11, 2020, Istanbul, Turkey
• IMX 2020, June 17-19, 2020, Barcelona, Spain
• MPEG131, Jun 29 – Jul 3, 2020, Geneva, Switzerland
• NetSoft,QoE Mgmt Workshop, Jun 29 – Jul 3, 2020, Ghent, Belgium
• ICME 2020, Jul 6-10, London, UK
• ATHENA summer school, Jul 13-17, Klagenfurt, Austria
• … and many more!

The original blog post can be found at the Bitmovin Techblog and has been modified/updated here to focus on and highlight research aspects.

The 126th MPEG meeting concluded on March 29, 2019 in Geneva, Switzerland with the following topics:

• Three Degrees of Freedom Plus (3DoF+) – MPEG evaluates responses to the Call for Proposal and starts a new project on Metadata for Immersive Video
• Neural Network Compression for Multimedia Applications – MPEG evaluates responses to the Call for Proposal and kicks off its technical work
• Low Complexity Enhancement Video Coding – MPEG evaluates responses to the Call for Proposal and selects a Test Model for further development
• Point Cloud Compression – MPEG promotes its Geometry-based Point Cloud Compression (G-PCC) technology to the Committee Draft (CD) stage
• MPEG Media Transport (MMT) – MPEG approves 3rd Edition of Final Draft International Standard
• MPEG-G – MPEG-G standards reach Draft International Standard for Application Program Interfaces (APIs) and Metadata technologies

The corresponding press release of the 126th MPEG meeting can be found here: https://mpeg.chiariglione.org/meetings/126

Three Degrees of Freedom Plus (3DoF+)

MPEG evaluates responses to the Call for Proposal and starts a new project on Metadata for Immersive Video

MPEG’s support for 360-degree video — also referred to as omnidirectional video — is achieved using the Omnidirectional Media Format (OMAF) and Supplemental Enhancement Information (SEI) messages for High Efficiency Video Coding (HEVC). It basically enables the utilization of the tiling feature of HEVC to implement 3DoF applications and services, e.g., users consuming 360-degree content using a head mounted display (HMD). However, rendering flat 360-degree video may generate visual discomfort when objects close to the viewer are rendered. The interactive parallax feature of Three Degrees of Freedom Plus (3DoF+) will provide viewers with visual content that more closely mimics natural vision, but within a limited range of viewer motion.

At its 126th meeting, MPEG received five responses to the Call for Proposals (CfP) on 3DoF+ Visual. Subjective evaluations showed that adding the interactive motion parallax to 360-degree video will be possible. Based on the subjective and objective evaluation, a new project was launched, which will be named Metadata for Immersive Video. A first version of a Working Draft (WD) and corresponding Test Model (TM) were designed to combine technical aspects from multiple responses to the call. The current schedule for the project anticipates Final Draft International Standard (FDIS) in July 2020.

Research aspects: Subjective evaluations in the context of 3DoF+ but also immersive media services in general are actively researched within the multimedia research community (e.g., ACM SIGMM/SIGCHI, QoMEX) resulting in a plethora of research papers. One apparent open issue is the gap between scientific/fundamental research and standards developing organizations (SDOs) and industry fora which often address the same problem space but sometimes adopt different methodologies, approaches, tools, etc. However, MPEG (and also other SDOs) often organize public workshops and there will be one during the next meeting, specifically on July 10, 2019 in Gothenburg, Sweden which will be about “Coding Technologies for Immersive Audio/Visual Experiences”. Further details are available here.

Neural Network Compression for Multimedia Applications

MPEG evaluates responses to the Call for Proposal and kicks off its technical work

Artificial neural networks have been adopted for a broad range of tasks in multimedia analysis and processing, such as visual and acoustic classification, extraction of multimedia descriptors or image and video coding. The trained neural networks for these applications contain a large number of parameters (i.e., weights), resulting in a considerable size. Thus, transferring them to a number of clients using them in applications (e.g., mobile phones, smart cameras) requires compressed representation of neural networks.

At its 126th meeting, MPEG analyzed nine technologies submitted by industry leaders as responses to the Call for Proposals (CfP) for Neural Network Compression. These technologies address compressing neural network parameters in order to reduce their size for transmission and the efficiency of using them, while not or only moderately reducing their performance in specific multimedia applications.

After a formal evaluation of submissions, MPEG identified three main technology components in the compression pipeline, which will be further studied in the development of the standard. A key conclusion is that with the proposed technologies, a compression to 10% or less of the original size can be achieved with no or negligible performance loss, where this performance is measured as classification accuracy in image and audio classification, matching rate in visual descriptor matching, and PSNR reduction in image coding. Some of these technologies also result in the reduction of the computational complexity of using the neural network or can benefit from specific capabilities of the target hardware (e.g., support for fixed point operations).

Research aspects: This topic has been addressed already in previous articles here and here. An interesting observation after this meeting is that apparently the compression efficiency is remarkable, specifically as the performance loss is negligible for specific application domains. However, results are based on certain applications and, thus, general conclusions regarding the compression of neural networks as well as how to evaluate its performance are still subject to future work. Nevertheless, MPEG is certainly leading this activity which could become more and more important as more applications and services rely on AI-based techniques.

Low Complexity Enhancement Video Coding

MPEG evaluates responses to the Call for Proposal and selects a Test Model for further development

MPEG started a new work item referred to as Low Complexity Enhancement Video Coding (LCEVC), which will be added as part 2 of the MPEG-5 suite of codecs. The new standard is aimed at bridging the gap between two successive generations of codecs by providing a codec-agile extension to existing video codecs that improves coding efficiency and can be readily deployed via software upgrade and with sustainable power consumption.

The target is to achieve:

• coding efficiency close to High Efficiency Video Coding (HEVC) Main 10 by leveraging Advanced Video Coding (AVC) Main Profile and
• coding efficiency close to upcoming next generation video codecs by leveraging HEVC Main 10.

This coding efficiency should be achieved while maintaining overall encoding and decoding complexity lower than that of the leveraged codecs (i.e., AVC and HEVC, respectively) when used in isolation at full resolution. This target has been met, and one of the responses to the CfP will serve as starting point and test model for the standard. The new standard is expected to become part of the MPEG-5 suite of codecs and its development is expected to be completed in 2020.

Research aspects: In addition to VVC and EVC, LCEVC is now the third video coding project within MPEG basically addressing requirements and needs going beyond HEVC. As usual, research mainly focuses on compression efficiency but a general trend in video coding is probably observable that favors software-based solutions rather than pure hardware coding tools. As such, complexity — both at encoder and decoder — is becoming important as well as power efficiency which are additional factors to be taken into account. Other issues are related to business aspects which are typically discussed elsewhere, e.g., here.

Point Cloud Compression

MPEG promotes its Geometry-based Point Cloud Compression (G-PCC) technology to the Committee Draft (CD) stage

MPEG’s Geometry-based Point Cloud Compression (G-PCC) standard addresses lossless and lossy coding of time-varying 3D point clouds with associated attributes such as color and material properties. This technology is appropriate especially for sparse point clouds.

MPEG’s Video-based Point Cloud Compression (V-PCC) addresses the same problem but for dense point clouds, by projecting the (typically dense) 3D point clouds onto planes, and then processing the resulting sequences of 2D images with video compression techniques.

G-PCC provides a generalized approach, which directly codes the 3D geometry to exploit any redundancy found in the point cloud itself and is complementary to V-PCC and particularly useful for sparse point clouds representing large environments.

Point clouds are typically represented by extremely large amounts of data, which is a significant barrier for mass market applications. However, the relative ease to capture and render spatial information compared to other volumetric video representations makes point clouds increasingly popular to present immersive volumetric data. The current implementation of a lossless, intra-frame G-PCC encoder provides a compression ratio up to 10:1 and acceptable quality lossy coding of ratio up to 35:1.

Research aspects: After V-PCC MPEG has now promoted G-PCC to CD but, in principle, the same research aspects are relevant as discussed here. Thus, coding efficiency is the number one performance metric but also coding complexity and power consumption needs to be considered to enable industry adoption. Systems technologies and adaptive streaming are actively researched within the multimedia research community, specifically ACM MM and ACM MMSys.

MPEG Media Transport (MMT)

MPEG approves 3rd Edition of Final Draft International Standard

MMT 3rd edition will introduce two aspects:

• enhancements for mobile environments and
• support of Contents Delivery Networks (CDNs).

The support for multipath delivery will enable delivery of services over more than one network connection concurrently, which is specifically useful for mobile devices that can support more than one connection at a time.

Additionally, support for intelligent network entities involved in media services (i.e., Media Aware Network Entity (MANE)) will make MMT-based services adapt to changes of the mobile network faster and better. Understanding the support for load balancing is an important feature of CDN-based content delivery, messages for DNS management, media resource update, and media request is being added in this edition.

On going developments within MMT will add support for the usage of MMT over QUIC (Quick UDP Internet Connections) and support of FCAST in the context of MMT.

Research aspects: Multimedia delivery/transport is still an important issue, specifically as multimedia data on the internet is increasing much faster than network bandwidth. In particular, the multimedia research community (i.e., ACM MM and ACM MMSys) is looking into novel approaches and tools utilizing exiting/emerging protocols/techniques like HTTP/2, HTTP/3 (QUIC), WebRTC, and Information-Centric Networking (ICN). One question, however, remains, namely what is the next big thing in multimedia delivery/transport as currently we are certainly in a phase where tools like adaptive HTTP streaming (HAS) reached maturity and the multimedia research community is eager to work on new topics in this domain.

The original blog post can be found at the Bitmovin Techblog and has been modified/updated here to focus on and highlight research aspects.

The 125th MPEG meeting concluded on January 18, 2019 in Marrakesh, Morocco with the following topics:

• Network-Based Media Processing (NBMP) – MPEG promotes NBMP to Committee Draft stage
• 3DoF+ Visual – MPEG issues Call for Proposals on Immersive 3DoF+ Video Coding Technology
• MPEG-5 Essential Video Coding (EVC) – MPEG starts work on MPEG-5 Essential Video Coding
• ISOBMFF – MPEG issues Final Draft International Standard of Conformance and Reference software for formats based on the ISO Base Media File Format (ISOBMFF)
• MPEG-21 User Description – MPEG finalizes 2nd edition of the MPEG-21 User Description

The corresponding press release of the 125th MPEG meeting can be found here. In this blog post I’d like to focus on those topics potentially relevant for over-the-top (OTT), namely NBMP, EVC, and ISOBMFF.

Network-Based Media Processing (NBMP)

The NBMP standard addresses the increasing complexity and sophistication of media services, specifically as the incurred media processing requires offloading complex media processing operations to the cloud/network to keep receiver hardware simple and power consumption low. Therefore, NBMP standard provides a standardized framework that allows content and service providers to describe, deploy, and control media processing for their content in the cloud. It comes with two main functions: (i) an abstraction layer to be deployed on top of existing cloud platforms (+ support for 5G core and edge computing) and (ii) a workflow manager to enable composition of multiple media processing tasks (i.e., process incoming media and metadata from a media source and produce processed media streams and metadata that are ready for distribution to a media sink). The NBMP standard now reached Committee Draft (CD) stage and final milestone is targeted for early 2020.

In particular, a standard like NBMP might become handy in the context of 5G in combination with mobile edge computing (MEC) which allows offloading certain tasks to a cloud environment in close proximity to the end user. For OTT, this could enable lower latency and more content being personalized towards the user’s context conditions and needs, hopefully leading to a better quality and user experience.

For further research aspects please see one of my previous posts. 

MPEG-5 Essential Video Coding (EVC)

MPEG-5 EVC clearly targets the high demand for efficient and cost-effective video coding technologies. Therefore, MPEG commenced work on such a new video coding standard that should have two profiles: (i) royalty-free baseline profile and (ii) main profile, which adds a small number of additional tools, each of which is capable, on an individual basis, of being either cleanly switched off or else switched over to the corresponding baseline tool. Timely publication of licensing terms (if any) is obviously very important for the success of such a standard.

The target coding efficiency for responses to the call for proposals was to be at least as efficient as HEVC. This target was exceeded by approximately 24% and the development of the MPEG-5 EVC standard is expected to be completed in 2020.

As of today, there’s the need to support AVC, HEVC, VP9, and AV1; soon VVC will become important. In other words, we already have a multi-codec environment to support and one might argue one more codec is probably not a big issue. The main benefit of EVC will be a royalty-free baseline profile but with AV1 there’s already such a codec available and it will be interesting to see how the royalty-free baseline profile of EVC compares to AV1.

For a new video coding format we will witness a plethora of evaluations and comparisons with existing formats (i.e., AVC, HEVC, VP9, AV1, VVC). These evaluations will be mainly based on objective metrics such as PSNR, SSIM, and VMAF. It will be also interesting to see subjective evaluations, specifically targeting OTT use cases (e.g., live and on demand).

ISO Base Media File Format (ISOBMFF)

The ISOBMFF (ISO/IEC 14496-12) is used as basis for many file (e.g., MP4) and streaming formats (e.g., DASH, CMAF) and as such received widespread adoption in both industry and academia. An overview of ISOBMFF is available here. The reference software is now available on GitHub and a plethora of conformance files are available here. In this context, the open source project GPAC is probably the most interesting aspect from a research point of view.

The original blog post can be found at the Bitmovin Techblog and has been modified/updated here to focus on and highlight research aspects.

The MPEG press release comprises the following aspects:

• Point Cloud Compression – MPEG promotes a video-based point cloud compression technology to the Committee Draft stage
• Compressed Representation of Neural Networks – MPEG issues Call for Proposals
• Low Complexity Video Coding Enhancements – MPEG issues Call for Proposals
• New Video Coding Standard expected to have licensing terms timely available – MPEG issues Call for Proposals
• Multi-Image Application Format (MIAF) promoted to Final Draft International Standard
• 3DoF+ Draft Call for Proposal goes Public

Point Cloud Compression – MPEG promotes a video-based point cloud compression technology to the Committee Draft stage

At its 124th meeting, MPEG promoted its Video-based Point Cloud Compression (V-PCC) standard to Committee Draft (CD) stage. V-PCC addresses lossless and lossy coding of 3D point clouds with associated attributes such as colour. By leveraging existing and video ecosystems in general (hardware acceleration, transmission services and infrastructure), and future video codecs as well, the V-PCC technology enables new applications. The current V-PCC encoder implementation provides a compression of 125:1, which means that a dynamic point cloud of 1 million points could be encoded at 8 Mbit/s with good perceptual quality.

A next step is the storage of V-PCC in ISOBMFF for which a working draft has been produced. It is expected that further details will be discussed in upcoming reports.

Research aspects: Video-based Point Cloud Compression (V-PCC) is at CD stage and a first working draft for the storage of V-PCC in ISOBMFF has been provided. Thus, a next consequence is the delivery of V-PCC encapsulated in ISOBMFF over networks utilizing various approaches, protocols, and tools. Additionally, one may think of using also different encapsulation formats if needed.

MPEG issues Call for Proposals on Compressed Representation of Neural Networks

Artificial neural networks have been adopted for a broad range of tasks in multimedia analysis and processing, media coding, data analytics, and many other fields. Their recent success is based on the feasibility of processing much larger and complex neural networks (deep neural networks, DNNs) than in the past, and the availability of large-scale training data sets. Some applications require the deployment of a particular trained network instance to a potentially large number of devices and, thus, could benefit from a standard for the compressed representation of neural networks. Therefore, MPEG has issued a Call for Proposals (CfP) for compression technology for neural networks, focusing on the compression of parameters and weights, focusing on four use cases: (i) visual object classification, (ii) audio classification, (iii) visual feature extraction (as used in MPEG CDVA), and (iv) video coding.

Research aspects: As point out last time, research here will mainly focus around compression efficiency for both lossy and lossless scenarios. Additionally, communication aspects such as transmission of compressed artificial neural networks within lossy, large-scale environments including update mechanisms may become relevant in the (near) future.

MPEG issues Call for Proposals on Low Complexity Video Coding Enhancements

Upon request from the industry, MPEG has identified an area of interest in which video technology deployed in the market (e.g., AVC, HEVC) can be enhanced in terms of video quality without the need to necessarily replace existing hardware. Therefore, MPEG has issued a Call for Proposals (CfP) on Low Complexity Video Coding Enhancements.

The objective is to develop video coding technology with a data stream structure defined by two component streams: a base stream decodable by a hardware decoder and an enhancement stream suitable for software processing implementation. The project is meant to be codec agnostic; in other words, the base encoder and base decoder can be AVC, HEVC, or any other codec in the market.

Research aspects: The interesting aspect here is that this use case assumes a legacy base decoder – most likely realized in hardware – which is enhanced with software-based implementations to improve coding efficiency or/and quality without sacrificing capabilities of the end user in terms of complexity and, thus, energy efficiency due to the software based solution. 

MPEG issues Call for Proposals for a New Video Coding Standard expected to have licensing terms timely available

At its 124th meeting, MPEG issued a Call for Proposals (CfP) for a new video coding standard to address combinations of both technical and application (i.e., business) requirements that may not be adequately met by existing standards. The aim is to provide a standardized video compression solution which combines coding efficiency similar to that of HEVC with a level of complexity suitable for real-time encoding/decoding and the timely availability of licensing terms.

Research aspects: This new work item is more related to business aspects (i.e., licensing terms) than technical aspects of video coding.

Multi-Image Application Format (MIAF) promoted to Final Draft International Standard

The Multi-Image Application Format (MIAF) defines interoperability points for creation, reading, parsing, and decoding of images embedded in High Efficiency Image File (HEIF) format by (i) only defining additional constraints on the HEIF format, (ii) limiting the supported encoding types to a set of specific profiles and levels, (iii) requiring specific metadata formats, and (iv) defining a set of brands for signaling such constraints including specific depth map and alpha plane formats. For instance, it addresses use case like a capturing device may use one of HEIF codecs with a specific HEVC profile and level in its created HEIF files, while a playback device is only capable of decoding the AVC bitstreams.

Research aspects: MIAF is an application format which is defined as a combination of tools (incl. profiles and levels) of other standards (e.g., audio codecs, video codecs, systems) to address the needs of a specific application. Thus, the research is related to use cases enabled by this application format. 

3DoF+ Draft Call for Proposal goes Public

Following investigations on the coding of “three Degrees of Freedom plus” (3DoF+) content in the context of MPEG-I, the MPEG video subgroup has provided evidence demonstrating the capability to encode a 3DoF+ content efficiently while maintaining compatibility with legacy HEVC hardware. As a result, MPEG decided to issue a draft Call for Proposal (CfP) to the public containing the information necessary to prepare for the final Call for Proposal expected to occur at the 125th MPEG meeting (January 2019) with responses due at the 126th MPEG meeting (March 2019).

Research aspects: This work item is about video (coding) and, thus, research is about compression efficiency.

What else happened at #MPEG124?

• MPEG-DASH 3rd edition is still in the final editing phase and not yet available. Last time, I wrote that we expect final publication later this year or early next year and we hope this is still the case. At this meeting Amendment.5 is progressed to DAM and conformance/reference software for SRD, SAND and Server Push is also promoted to DAM. In other words, DASH is pretty much in maintenance mode.
• MPEG-I (systems part) is working on immersive media access and delivery and I guess more updates will come on this after the next meeting. OMAF is working on a 2nd edition for which a working draft exists and phase 2 use cases (public document) and draft requirements are discussed.
• Versatile Video Coding (VVC): working draft 3 (WD3) and test model 3 (VTM3) has been issued at this meeting including a large number of new tools. Both documents (and software) will be publicly available after editing periods (Nov. 23 for WD3 and Dec 14 for VTM3).

The original blog post can be found at the Bitmovin Techblog and has been modified/updated here to focus on and highlight research aspects.

The MPEG press release comprises the following topics:

• MPEG issues Call for Evidence on Compressed Representation of Neural Networks
• Network-Based Media Processing – MPEG evaluates responses to call for proposal and kicks off its technical work
• MPEG finalizes 1st edition of Technical Report on Architectures for Immersive Media
• MPEG releases software for MPEG-I visual activities
• MPEG enhances ISO Base Media File Format (ISOBMFF) with new features

MPEG issues Call for Evidence on Compressed Representation of Neural Networks

Artificial neural networks have been adopted for a broad range of tasks in multimedia analysis and processing, media coding, data analytics, translation and many other fields. Their recent success is based on the feasibility of processing much larger and complex neural networks (deep neural networks, DNNs) than in the past, and the availability of large-scale training data sets. As a consequence, trained neural networks contain a large number of parameters (weights), resulting in a quite large size (e.g., several hundred MBs). Many applications require the deployment of a particular trained network instance, potentially to a larger number of devices, which may have limitations in terms of processing power and memory (e.g., mobile devices or smart cameras). Any use case, in which a trained neural network (and its updates) needs to be deployed to a number of devices could thus benefit from a standard for the compressed representation of neural networks.

At its 123rd meeting, MPEG has issued a Call for Evidence (CfE) for compression technology for neural networks. The compression technology will be evaluated in terms of compression efficiency, runtime, and memory consumption and the impact on performance in three use cases: visual object classification, visual feature extraction (as used in MPEG Compact Descriptors for Visual Analysis) and filters for video coding. Responses to the CfE will be analyzed on the weekend prior to and during the 124th MPEG meeting in October 2018 (Macau, CN).

Research aspects: As this is about “compression” of structured data, research aspects will mainly focus around compression efficiency for both lossy and lossless scenarios. Additionally, communication aspects such as transmission of compressed artificial neural networks within lossy, large-scale environments including update mechanisms may become relevant in the (near) future. Furthermore, additional use cases should be communicated towards MPEG until the next meeting.

Network-Based Media Processing – MPEG evaluates responses to call for proposal and kicks off its technical work

Recent developments in multimedia have brought significant innovation and disruption to the way multimedia content is created and consumed. At its 123rd meeting, MPEG analyzed the technologies submitted by eight industry leaders as responses to the Call for Proposals (CfP) for Network-Based Media Processing (NBMP, MPEG-I Part 8). These technologies address advanced media processing use cases such as network stitching for virtual reality (VR) services, super-resolution for enhanced visual quality, transcoding by a mobile edge cloud, or viewport extraction for 360-degree video within the network environment. NBMP allows service providers and end users to describe media processing operations that are to be performed by the entities in the networks. NBMP will describe the composition of network-based media processing services out of a set of NBMP functions and makes these NBMP services accessible through Application Programming Interfaces (APIs).

NBMP will support the existing delivery methods such as streaming, file delivery, push-based progressive download, hybrid delivery, and multipath delivery within heterogeneous network environments. MPEG issued a Call for Proposal (CfP) seeking technologies that allow end-user devices, which are limited in processing capabilities and power consumption, to offload certain kinds of processing to the network.

After a formal evaluation of submissions, MPEG selected three technologies as starting points for the (i) workflow, (ii) metadata, and (iii) interfaces for static and dynamically acquired NBMP. A key conclusion of the evaluation was that NBMP can significantly improve the performance and efficiency of the cloud infrastructure and media processing services.

Research aspects: I reported about NBMP in my previous post and basically the same applies here. NBMP will be particularly interesting in the context of new networking approaches including, but not limited to, software-defined networking (SDN), information-centric networking (ICN), mobile edge computing (MEC), fog computing, and related aspects in the context of 5G.

MPEG finalizes 1st edition of Technical Report on Architectures for Immersive Media

At its 123nd meeting, MPEG finalized the first edition of its Technical Report (TR) on Architectures for Immersive Media. This report constitutes the first part of the MPEG-I standard for the coded representation of immersive media and introduces the eight MPEG-I parts currently under specification in MPEG. In particular, it addresses three Degrees of Freedom (3DoF; three rotational and un-limited movements around the X, Y and Z axes (respectively pitch, yaw and roll)), 3DoF+ (3DoF with additional limited translational movements (typically, head movements) along X, Y and Z axes), and 6DoF (3DoF with full translational movements along X, Y and Z axes) experiences but it mostly focuses on 3DoF. Future versions are expected to cover aspects beyond 3DoF. The report documents use cases and defines architectural views on elements that contribute to an overall immersive experience. Finally, the report also includes quality considerations for immersive services and introduces minimum requirements as well as objectives for a high-quality immersive media experience.

Research aspects: ISO/IEC technical reports are typically publicly available and provides informative descriptions of what the standard is about. In MPEG-I this technical report can be used as a guideline for possible architectures for immersive media. This first edition focuses on three Degrees of Freedom (3DoF; three rotational and un-limited movements around the X, Y and Z axes (respectively pitch, yaw and roll)) and outlines the other degrees of freedom currently foreseen in MPEG-I. It also highlights use cases and quality-related aspects that could be of interest for the research community.

MPEG releases software for MPEG-I visual activities

MPEG-I visual is an activity that addresses the specific requirements of immersive visual media for six degrees of freedom virtual walkthroughs with correct motion parallax within a bounded volume. MPEG-I visual covers application scenarios from 3DoF+ with slight body and head movements in a sitting position to 6DoF allowing some walking steps from a central position. At the 123nd MPEG meeting, an important progress has been achieved in software development. A new Reference View Synthesizer (RVS 2.0) has been released for 3DoF+, allowing to synthesize virtual viewpoints from an unlimited number of input views. RVS integrates code bases from Universite Libre de Bruxelles and Philips, who acted as software coordinator. A Weighted-to-Spherically-uniform PSNR (WS-PSNR) software utility, essential to 3DoF+ and 6DoF activities, has been developed by Zhejiang University. WS-PSNR is a full reference objective quality metric for all flavors of omnidirectional video. RVS and WS-PSNR are essential software tools for the upcoming Call for Proposals on 3DoF+ expected to be released at the 124th MPEG meeting in October 2018 (Macau, CN).

Research aspects: MPEG does not only produce text specifications but also reference software and conformance bitstreams, which are important assets for both research and development. Thus, it is very much appreciated to have a new Reference View Synthesizer (RVS 2.0) and Weighted-to-Spherically-uniform PSNR (WS-PSNR) software utility available which enables interoperability and reproducibility of R&D efforts/results in this area.

MPEG enhances ISO Base Media File Format (ISOBMFF) with new features

At the 123rd MPEG meeting, a couple of new amendments related to ISOBMFF has reached the first milestone. Amendment 2 to ISO/IEC 14496-12 6th edition will add the option to have relative addressing as an alternative to offset addressing, which in some environments and workflows can simplify the handling of files and will allow creation of derived visual tracks using items and samples in other tracks with some transformation, for example rotation. Another amendment reached its first milestone is the first amendment to ISO/IEC 23001-7 3rd edition. It will allow use of multiple keys to a single sample and scramble some parts of AVC or HEVC video bitstreams without breaking conformance to the existing decoders. That is, the bitstream will be decodable by existing decoders, but some parts of the video will be scrambled. It is expected that these amendments will reach the final milestone in Q3 2019.

Research aspects: The ISOBMFF reference software is now available on Github, which is a valuable service to the community and allows for active standard’s participation even from outside of MPEG. It is recommended that interested parties have a look at it and consider contributing to this project.

What else happened at #MPEG123?

• The MPEG-DASH 3rd edition is finally available as output document (N17813; only available to MPEG members) combining 2nd edition, four amendments, and 2 corrigenda. We expect final publication later this year or early next year.
• There is a new DASH amendment and corrigenda items in pipeline which should progress to final stages also some time next year. The status of MPEG-DASH (July 2018) can be seen below.

• MPEG received a rather interesting input document related to “streaming first” which resulted into a publicly available output document entitled “thoughts on adaptive delivery and access to immersive media”. The key idea here is to focus on streaming (first) rather than on file/encapsulation formats typically used for storage (and streaming second). This document should become available here.
• Since a couple of meetings, MPEG maintains a standardization roadmap highlighting recent/major MPEG standards and documenting the roadmap for the next five years. It definitely worth keeping this in mind when defining/updating your own roadmap.
• JVET/VVC issued Working Draft 2 of Versatile Video Coding (N17732 | JVET-K1001) and Test Model 2 of Versatile Video Coding (VTM 2) (N17733 | JVET-K1002). Please note that N-documents are MPEG internal but JVET-documents are publicly accessible here: http://phenix.it-sudparis.eu/jvet/. An interesting aspect is that VTM2/WD2 should have >20% rate reduction compared to HEVC, all with reasonable complexity and the next benchmark set (BMS) should have close to 30% rate reduction vs. HEVC. Further improvements expected from (a) improved merge, intra prediction, etc., (b) decoder-side estimation with low complexity, (c) multi-hypothesis prediction and OBMC, (d) diagonal and other geometric partitioning, (e) secondary transforms, (f) new approaches of loop filtering, reconstruction and prediction filtering (denoising, non-local, diffusion based, bilateral, etc.), (g) current picture referencing, palette, and (h) neural networks.
• In addition to VVC — which is a joint activity with VCEG –, MPEG is working on two video-related exploration activities, namely (a) an enhanced quality profile of the AVC standard and (b) a low complexity enhancement video codec. Both topics will be further discussed within respective Ad-hoc Groups (AhGs) and further details are available here.
• Finally, MPEG established an Ad-hoc Group (AhG) dedicated to the long-term planning which is also looking into application areas/domains other than media coding/representation.

In this context it is probably worth mentioning the following DASH awards at recent conferences

• June 2018, DASH-IF awarded Excellence in DASH award at ACM MMSys 2018
• July 2018, DASH-IF awarded Grand Challenge on Dynamic Adaptive Streaming over HTTP at IEEE ICME 2018

Additionally, there have been two tutorials at ICME related to MPEG standards, which you may find interesting

• Trends and Recent Developments in Video Coding Standardization
• Delivering Traditional and Omnidirectional Media