Maheshi B. Dissanayake

Redundant motion vectors for improved error resilience in H.264/AVC coded video

This proposal presents a new error robust strategy for encoding redundant pictures for the H.264/AVC standard. The method is based on providing motion vectors as redundant data, i.e. providing extra protection to the motion information of the encoded stream. The proposed system is implemented based on the existing redundant coding algorithm of the scalable extension of H.264/AVC. The performance of the algorithm is evaluated using various objective quality measurements under both error free and error prone Internet protocol (IP) packet network environments. The proposed algorithm increases the bandwidth utilization with slight degradation in the primary picture quality for error free conditions, compared to the existing redundant coding method of JSVM (joint scalable video model). Furthermore, the simulation results under packet loss environments show that the proposed algorithm outperforms the existing redundant picture coding of JSVM.

A scalable multi-view audiovisual entertainment framework with content-aware distribution

Delivery of 3D immersive entertainment to the home remains a highly challenging problem due to the large amount of data involved, and the need to support a wide variety of different displays. Support of such displays may require different numbers of views, delivered over time varying networks. This requires a delivery scheme featuring scalable compression to adapt to varying network conditions, and error resiliency to overcome disturbing losses in the 3D perception. Audio and video attention models can be used in designing an optimal content-aware compression and transmission scheme, by prioritizing the most visually important areas of the video. This paper gives an overview of a content-aware, scalable multi-view audiovisual entertainment delivery framework. Results are shown to evaluate the kinds of error robustness improvements that could be seen using such a system.

Error resilience technique for multi-view coding using redundant disparity vectors

Research on error resilience in multi-view coding is currently receiving considerable interest. While there is a multitude of literature concerning error recovery in 2D video, due to the statistical difference in motion compensation among temporal frames and disparity compensation among view points, such methods are inadequate to cater to the requirements of multiview video transmission. This paper addresses the above issue by transmission of redundant disparity vectors for error recovery purposes. The proposed system, which is implemented using the Joint Scalable Video Model (JSVM) codec and tested using a simulated Internet Protocol (IP) packet network environment, can be used along with a suitable error concealment scheme to provide robust multi-view video transmission. The experimental results suggest that the proposed algorithm experiences a slight degradation of quality in error free environments due to the inclusion of redundant data. However, it improves the reconstructed picture quality significantly in error prone environments, specifically for Packet Loss Rates (PLRs) greater than 7%.

EGC Diversity Reception of CPSK Signals in Nakagami Fading

A novel method for evaluating the symbol error rate of M-ary CPSK signals received over Nakagami-w fading channels with equal-gain combining (EGC) is presented. The new method does not rely on the characteristic function of the sum of Nakagami random variables. The error rate of CPSK signals for L-channel diversity is expressed as a L-fold integral. The multiple integrals can be efficiently computed using either the Gauss-Hermite quadrature or the Gauss-Laguerre quadrature integration formulas to obtain accurate numerical results. Numerical values for the error rates of 2-, 4- and 8-CPSK signals for EGC diversity reception are presented

Performance Comparison of HEVC and H.264/AVC Standards in Broadcasting Environments

High Efficiency Video Coding (HEVC) is the most recent video codec standard of the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. The main goal of this newly introduced standard is for catering to high-resolution video in low bandwidth environments with a higher compression ratio. This paper provides a performance comparison between HEVC and H.264/AVC video compression standards in terms of objective quality, delay, and complexity in the broadcasting environment. The experimental investigation was carried out using six test sequences in the random access configuration of the HEVC test model (HM), the HEVC reference software. This was also carried out in similar configuration settings of the Joint Scalable Video Module (JSVM), the official scalable H.264/AVC reference implementation, running on a single layer mode. According to the results obtained, the HM achieves more than double the compression ratio compared to that of JSVM and delivers the same video quality at half the bitrate. Yet, the HM encodes two times slower (at most) than JSVM. Hence, it can be concluded that the application scenarios of HM and JSVM should be judiciously selected considering the availability of system resources. For instance, HM is not suitable for low delay applications, but it can be used effectively in low bandwidth environments.

Reed Solomon Codes for Molecular Communication With a Full Absorption Receiver

Molecular communication (MC) has recently emerged as a novel paradigm for nano-scale communication utilizing molecules as information carriers. In diffusion-based molecular communication, the system performance is constrained by the inter-symbol-interference caused by the crossover of information carrying molecules in consecutive bits. To cope with this, we propose the Reed-Solomon (RS) codes as an error recovery tool, to improve the transmission reliability in diffusion-based MC systems. To quantify the performance improvement due to RS codes, we derive the analytical expression for the approximate bit error probability (BEP) of the diffusion-based MC system with the full absorption receiver. We further develop the particle-based simulation framework to simulate the proposed system with RS code to verify the accuracy of our derived analytical results. Our results show that, as the number of molecules per bit increases, the BEP of the system with RS codes exhibits a substantial improvement than that of non-coded systems. Furthermore, the BEP of the proposed system with RS codes can be greatly improved by increasing the minimum distance of the codeword.

Wyner-Ziv based error correction of non-key frames for low complexity streaming applications

The paper presents a novel error robustness method for H.264/AVC video data, based on the redundant data encoding concept. The proposed redundant data codec incorporates the Wyner-Ziv (WZ) theory and motion vectors (MV) of the H.264/AVC scheme. The performance of the proposed method is evaluated under both error free and error prone Internet Protocol (IP) Packet network environments. The proposed architecture improves the error recovery of the system in terms of objective quality. Furthermore, the simulation outcome shows that the proposed method outperforms the existing redundant coding method of JSVM by 0.7 dB in an error free environment and by 0.4 dB in a 10% packet loss rate (PLR) environment with medium and high motion sequences.

Edge based frame interpolation technique for error correction at HEVC decoder

This paper mainly focuses on introducing an edge based bi-directional frame interpolation technique to increase performance of the High Efficiency Video Coding (HEVC) standard in error prone environment. The main aim of the proposed technique is to maintain the structural similarity between the dropped frame and the interpolated frame, while keeping the redundant data transmission at a minimum level. Further, the technique presented provides a simple low cost method for frame interpolation based error recovery in HEVC. The experimental results show that the proposed technique manages to recover the lost frame with an acceptable level of PSNR and SSIM level while maintaining the redundant data rate at a minimum level.