Bandwidth Efficient IPTV Distribution : On Error Resilience and Fast Channel Change

Television is now changing its traditional distribution forms to being distributed digitally over broadband networks. The recent development of broadband Internet connectivity has made the transition to Internet Protocol Television (IPTV) possible. When changing distribution technique of an existing service, it is important that the new technique does not make the service worse from the user’s point of view. Although a broadband network offers high capacity and has excellent performance there will be occasional packet losses and delays which could negatively influence the user experience of the delivered broadband service. Since bandwidth is a key constraint for video distribution there is a strong incentive for finding schemes to increase bandwidth utilization, especially when distributing high bandwidth IPTV services. In digital video coding it is common to use predictive coding to remove temporal redundancy in video sequences. This technique greatly increases the coding efficiency but makes the sequence more sensitive to information loss or delay. In addition, the use of predictive coding also introduce a inter frame dependency which could make the channel change significantly slower. This thesis addresses two important areas related to bandwidth efficient IPTV distribution, namely error resilience and fast channel change. A method to numerically estimate the decoded objective video quality of scalable coded video is presented and evaluated. The method can be used to estimate objective video quality for a scalable video transmission system subject to packet-loss. The quality gain of temporally scalable video in a priority packet dropping environment is also investigated and quantified. Synchronization Frames for Channel Switching (SFCS) is proposed as a method to code and distribute video with IP-multicast, which can be used to efficiently combat packet-loss, increase bandwidth utilization, and offer a channel change speed up. The performance of SFCS is analyzed and bandwidth estimation expressions are formulated, analytical results are complemented with computer simulations. The results show that SFCS deployed in an IPTV delivery system can significantly lower the bandwidth consumption and speed up the channel change

Low Delay Video Streaming on the Internet of Things Using Raspberry Pi

The Internet of Things is predicted to consist of over 50 billion devices aiming to solve problems in most areas of our digital society. A large part of the data communicated is expected to consist of various multimedia contents, such as live audio and video. This article presents a solution for the communication of high definition video in low-delay scenarios (<200 ms) under the constraints of devices with limited hardware resources, such as the Raspberry Pi. We verify that it is possible to enable low delay video streaming between Raspberry Pi devices using a distributed Internet of Things system called the SensibleThings platform. Specifically, our implementation transfers a 6 Mbps H.264 video stream of 1280 × 720 pixels at 25 frames per second between devices with a total delay of 181 ms on the public Internet, of which the overhead of the distributed Internet of Things communication platform only accounts for 18 ms of this delay. We have found that the most significant bottleneck of video transfer on limited Internet of Things devices is the video coding and not the distributed communication platform, since the video coding accounts for 90% of the total delay

Overlay Enhanced Mobility for the Internet of Things

One of the major challenges to realize the Internet of Things is to support IP mobility for the large amount of connected entities when they move between different locations and access methods. Current solutions for mobility are host centric, requiring support from the infrastructure, or breaks backwards compatibility, which will take a long time or high economic motivation to implement. Solutions for context information exchange are created for specific, small, or localized scenarios with centralized coordination that do not scale well. There is therefore a need for a solution which both scales well, and support IP mobility, without additional demands on current or future Internet infrastructure.We propose the use of a dual-overlay network structure for both information dissemination and as an alternative to current IP mobility technologies. It separates identities from location by introducing a second overlay network where the identity-to-location association is stored. We show analytically that the proposed solution provide logarithmic latency for localization and reduces the overall workload when the number of sensors per host increases beyond seven, with a workload reduction of 15 percentage points at fifteen sensors per host

Depth Map Compression with Diffusion Modes in 3D-HEVC

For three-dimensional television, multiple views can be generated by using the Multi-view Video plus Depth (MVD) format. The depth maps of this format can be compressed efficiently by the 3D extension of High Efficiency Video Coding (3D-HEVC), which has explored the correlations between its two components, texture and associated depth map. In this paper, we introduce two modes for depth map coding into HEVC, where the modes use diffusion. The framework for inter-component prediction of Depth Modeling Modes (DMM) is utilized for the proposed modes. They detect edges from textures and then diffuse an entire block from known adjacent blocks by using Laplace equation constrained by the detected edges. The experimental results show that depth maps can be compressed more efficiently with the proposed diffusion modes, where the bit rate saving can reach 1.25 percentage of the total depth bit rate with a constant quality of synthesized views

Scalable coding of plenoptic images by using a sparse set and disparities

One of the light field capturing techniques is the focused plenoptic capturing. By placing a microlens array in front of the photosensor, the focused plenoptic cameras capture both spatial and angular information of a scene in each microlens image and across microlens images. The capturing results in significant amount of redundant information, and the captured image is usually of a large resolution. A coding scheme that removes the redundancy before coding can be of advantage for efficient compression, transmission and rendering. In this paper, we propose a lossy coding scheme to efficiently represent plenoptic images. The format contains a sparse image set and its associated disparities. The reconstruction is performed by disparity-based interpolation and inpainting, and the reconstructed image is later employed as a prediction reference for the coding of the full plenoptic image. As an outcome of the representation, the proposed scheme inherits a scalable structure with three layers.The results show that plenoptic images are compressed efficiently with over 60 percent bit rate reduction compared to HEVC intra, and with over 20 percent compared to HEVC block copying mode

Efficient Intra Prediction Scheme For Light Field Image Compression

Interactive photo-realistic graphics can be rendered by using light field datasets. One way of capturing the dataset is by using light field cameras with microlens arrays. The captured images contain repetitive patterns resulted from adjacent mi-crolenses. These images don't resemble the appearance of a natural scene. This dissimilarity leads to problems in light field image compression by using traditional image and video encoders, which are optimized for natural images and video sequences. In this paper, we introduce the full inter-prediction scheme in HEVC into intra-prediction for the compression of light field images. The proposed scheme is capable of performing both unidirectional and bi-directional prediction within an image. The evaluation results show that above 3 dB quality improvements or above 50 percent bit-rate saving can be achieved in terms of BD-PSNR for the proposed scheme compared to the original HEVC intra-prediction for light field images

Elastic Provisioning of Internet of Things Services Using Fog Computing: An Experience Report

The adoption of cloud and fog computing techniques for elastic provisioning of quality-constrained industrial Internet of Things (IoT) services is largely envisioned as very promising, but experience reports and lessons learned from real deployment still lack. To fill this gap, this paper presents and reports the evaluation of a system consisting of virtual services in a combined fog, cloud, and IoT setting, made up of multiple devices with varying computation capabilities. In particular, we have utilized and integrated off-the-shelf solutions into our architecture and have experimentally investigated the benefits of virtualization to move and redeploy mobile components to the fog nodes closest to the targeted end devices. In addition, the paper proposes an original solution to dynamically scale and provision the resources for the fog computing layer by using geometric monitoring. The reported results show the feasibility and efficiency of the proposed exploitation of both fog and cloud virtualized resources to enable scalability in the domain of IoT-assisted mobile presence services

Emerging applications through low-power wireless technologies for Internet of Things

SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle

A Scalable Coding Approach for High Quality Depth Image Compression

The distortion by using traditional video encoders (e.g. H.264) on the depth discontinuity can introduce disturbing effects on the synthesized view. The proposed scheme aims at preserving the most significantdepth transition for a better view synthesis. Furthermore, it has a scalable structure. The scheme extracts edge contours from a depth image and represents them by chain code. The chain code and the sampleddepth values on each side of the edge contour are encoded by differential and arithmetic coding. The depthimage is reconstructed by diffusion of edge samples and uniform sub-samples from the low quality depthimage. At low bit rates, the proposed scheme outperforms HEVC intra at the edges in the synthesized views, which correspond to the significant discontinuities in the depth image. The overall quality is also better with the proposed scheme at low bit rates for contents with distinct depth transition. © 2012 IEEE