By extracting the control plane from the data plane, SDN enables unprecedented flexibility for future network architectures and quickly changes the landscape of the networking industry. Although the maturity of commonly accepted SDN security practices is the key to the proliferation of cloud DCN, SDN security research is still in its infancy. This paper gives a top-down survey of the approaches in this area, discussing security challenges and opportunities of software-defined datacenter networking for cloud computing. It leverages the well-known confidentiality-integrity-availability (CIA) matrix and protection-detection-reaction (PDR) model to give an overview of current security threats and security measures. It also discusses promising research directions in this field.

Over the past two decades, significant progress has been made in the coding, analysis, and transmission of digital audio, video, and images. Digital multimedia signal processing technologies have arisen out of practical necessity and have significantly affected the multimedia industry. This special issue contains nine papers written by experts from academia and industry. The papers detail the most recent achievements in audio and video coding analysis and transmission and give an overview of emerging technologies. The paper by Ping Wu et al. introduces high-efficiency video coding (HEVC).
This new video coding standard greatly improves on the coding efficiency of H.264/AVC and is a milestone in digital video coding standards. In this paper, the technical features of HEVC (up to HEVC CD stage) are discussed.
The paper by Yichen Zhang and Lu Yu discusses the ongoing standardization of MPEG’s 3D video (3DV) coding. In this paper, coding tools proposed in response to MPEG’s Call for Proposals on 3DV coding are summarized.
The paper by Siwei Ma et al. gives an overview of the 3DV coding standard developed by the China Audio Video Coding Standard (AVS) Working Group.
The paper by Euee S. Jang describes a configurable codec framework. Video codec devices are becoming increasingly complex because of a wider range of applications. MPEG suggests tackling the problem with a reconfigurable video coding (RVC) framework and by standardizing modular definitions of tools and their connections. This paper gives a comprehensive overview of the RVC standard.
The paper by Minjie Xie describes lattice vector quantization (LVQ) algorithm for speech and audio coding. Various LVQ schemes have been developed for speech and audio coding, and some of these have been successfully used in ITU-T G.718 and G.719, 3GPPAMR-WB+, and MPEG USAC.
In the paper by Stephane Ragot et al., noise feedback coding (NFC) NFC is reviewed, and a novel coding technique is proposed. The technique involves using noise shaping in embedded pulse code modulation (PCM) and adaptive differential PCM (ADPCM).
The paper by Gerard Fernando describes the newest multimedia transport (MMT) standard, developed by MPEG. This paper describes the architecture and functions of MMT up to the MMT CD stage, and it lists the advantages and shortfalls of existing technologies.
The paper by Zhijie Zhao et al. describes low-complexity error resilience and error concealment for the scalable extension of H.264/AVC (SVC). This paper describes multiple description coding (MDC) for the encoder. It also describes an error concealment method in network abstraction layer (NAL) for decoder when medium grain scalability (MGS) is used. This method requires minimal computation and is suitable for real-time video streaming. In this paper, experimental results are also given.
The paper by Ling-Yu Duan et al. introduces the MPEG standard on compact descriptors for visual search (CDVS) for mobile applications. MPEG is developing a competitive and collaborative platform for evaluating existing visual search technologies. They are also developing a standard for visual descriptors.