Daniele Renzi

Scalable Media Coding Enabling Content-Aware Networking

Increasingly popular multimedia services are expected to play a dominant role in the future of the Internet. In this context, it is essential that content-aware networking (CAN) architectures explicitly address the efficient delivery and processing of multimedia content. This article proposes the adoption of a content-aware approach into the network infrastructure, thus making it capable of identifying, processing, and manipulating media streams and objects in real time to maximize quality of service (QoS) and experience (QoE). Our proposal is built on the exploitation of scalable media coding technologies within such a content-aware networking environment. This discussion is based on four representative use cases for media delivery (unicast, multicast, peer-to-peer, and adaptive HTTP streaming) and reviews CAN challenges, specifically flow processing, caching/buffering, and QoS/QoE management.

Video Content Adaptation Based on SVC and Associated RTP Packet Loss Detection and Signaling

The development of Scalable Video Coding (SVC) has been directed to serve a wide range of terminals over heterogeneous networks with the same encoded bit stream. SVC provides an elegant solution to adapt the video content, as it allows terminal and/or gateways accessing only a sub-part of the stream, without affecting the semantics of the source video signal. This paper describes adaptation mechanisms based on SVC, focusing on the implementation in the context of the IST project ENTHRONE. A particular emphasis is placed on adaptation techniques based on SVC NAL unit header extension, and on innovative RTP packet loss handling mechanisms, specifically conceived to handle losses in scenarios where SVC to SVC and SVC to H.264/AVC adaptation is performed and layered multicast cannot be used.

Scalable Video Coding in Content-Aware Networks: Research Challenges and Open Issues

The demand for access to advanced, distributed media resources is nowadays omnipresent due to the availability of Internet connectivity almost anywhere and anytime, and of a variety of different devices. This calls for rethinking of the current Internet architecture by making the network aware of which content is actually transported. This paper introduces Scalable Video Coding (SVC) as a tool for Content-Aware Networks (CANs) which is currently researched as part of the EU FP7 ALICANTE project. The architecture of ALICANTE with respect to SVC and CAN is presented, use cases are described, and finally research challenges and open issues are discussed.

Development and optimization of high level dataflow programs: The HEVC decoder design case

With the standardization of the new High Efficiency Video Coding (HEVC) compression algorithm, a dataflow specification of the HEVC decoding process is also available as part of the standard. This paper presents methodologies to improve and optimize the performance of implementations derived by the dataflow specification. Regarding the architectural aspect of dataflow network, the throughput has been increased by developing more potential parallelism. For the platform aspect, critical processes have been optimized by applying SIMD functions and communications have been improved by cache efficient FIFO implementation. Results revealed an average acceleration factor of 7 in the decoding framerate over the reference dataflow implementation.

Performance evaluation of H264/SVC streaming system featuring real-time in-network adaptation

In the recent years one of the most active research topics in multimedia networking is the exploitation of the Scalable Video Coding (SVC) as a scalable solution for efficient network resources utilization. SVC introduces scalability by exploiting a layered encoding of the video stream, thus enabling real-time in-network adaptation by selectively allowing the transmission of appropriate layers. This paper presents an architecture that exploits SVC capabilities in order to provide end-to-end QoS assurance via in-network video adaptation. The adaptation system management is based on MPEG-21 framework while the network QoS mechanisms are based on DiffServ standard. The performance evaluation of the proposed architecture is performed over a real test-bed infrastructure.

A multimedia terminal for adaptation and End-to-End QoS control

This paper addresses multimedia end user system design for content distribution over heterogeneous networks and terminals, with particular focus on end-to-end quality of service (QoS) control. A multimedia terminal comprising content-related metadata processor, usage environment characteristics provider, end user QoS monitor and H.264psilas extension scalable video coding (SVC) audio-visual player in coordination under a terminal middleware, has been conceived and implemented. This end user terminal enables end-to-end QoS control for content adaptation solution both in semantic and physical approaches to maximize end userpsilas perceptual experience and minimize resources. Such design approach illustrates a possible architecture for next generation multimedia end user terminal supporting MPEG-21 and H.264psilas extension SVC codec standards.

On the Development and Optimization of HEVC Video Decoders Using High-Level Dataflow Modeling

With the emergence of the High Efficiency Video Coding (HEVC) standard, a dataflow description of the decoder part was developed as part of the MPEG-B standard. This dataflow description presented modest framerate results which led us to propose methodologies to improve the performance. In this paper, we introduce architectural improvements by exposing more parallelism using YUV and frame-based parallel decoding. We also present platform optimizations based on the use of SIMD functions and cache efficient FIFOs. Results show an average acceleration factor of 5.8 in the decoding framerate over the reference architecture.

A Multimedia Terminal Supporting Adaptation for QoS Control

This paper addresses the end-to-end quality of service (QoS) guarantees and control for multimedia content delivery over heterogeneous networks, with a particular focus on end user terminal perspective. A multimedia terminal which embeds different probes to monitor network conditions and end user perceptual characteristics has been conceived and implemented. A series of QoS mapping between perception and adaptation spaces are yielded by means of the parameters provided by the QoS probes, facilitating content adaptation enabled by any generic adaptation server or intermediate service. Such a design approach illustrates a possible architecture for next-generation multimedia end user system supporting QoS control and content adaptation over a heterogeneous delivery chain.

An introduction to MPEG-G, the new ISO standard for genomic information representation

The MPEG-G standardization initiative is a coordinated international effort to specify a compressed data format that enables large scale genomic data to be processed, transported and shared. The standard consists of a set of specifications (i.e., a book) describing: i) a nor-mative format syntax, and ii) a normative decoding process to retrieve the information coded in a compliant file or bitstream. Such decoding process enables the use of leading-edge com-pression technologies that have exhibited significant compression gains over currently used formats for storage of unaligned and aligned sequencing reads. Additionally, the standard provides a wealth of much needed functionality, such as selective access, data aggregation, ap-plication programming interfaces to the compressed data, standard interfaces to support data protection mechanisms, support for streaming and a procedure to assess the conformance of implementations. ISO/IEC is engaged in supporting the maintenance and availability of the standard specification, which guarantees the perenniality of applications using MPEG-G. Fi-nally, the standard ensures interoperability and integration with existing genomic information processing pipelines by providing support for conversion from the FASTQ/SAM/BAM file formats. In this paper we provide an overview of the MPEG-G specification, with particular focus on the main advantages and novel functionality it offers. As the standard only specifies the decoding process, encoding performance, both in terms of speed and compression ratio, can vary depending on specific encoder implementations, and will likely improve during the lifetime of MPEG-G. Hence, the performance statistics provided here are only indicative baseline examples of the technologies included in the standard.

Distributed adaptation decision-taking framework and Scalable Video Coding tunneling for edge and in-network media adaptation

Existing and future media ecosystems need to cope with the ever-increasing heterogeneity of networks, devices, and user characteristics collectively referred to as (usage) context. The key to address this problem is media adaptation to various and dynamically changing contexts in order to provide a service quality that is regarded as satisfactory by the end user. The adaptation can be performed in many ways and at different locations, e.g., at the edge and within the network resulting in a substantial number of issues to be integrated within a media ecosystem. This paper describes research challenges, key innovations, target research outcomes, and achievements so far for edge and in-network media adaptation by introducing the concept of Scalable Video Coding (SVC) tunneling.