In the first part, decoder based error concealment methods are discussed. An adaptive partition size (APS) temporal error concealment method is developed for H.264. We propose to use Weighted Double-Sided External Boundary Matching Error (WDS-EBME) to jointly measure the inter-MB boundary discontinuity, inter-partition boundary discontinuity and intra-partition block artifacts in the corrupted MB. By minimizing the WDS-EBME value of each partition, the best motion vectors of each candidate partition mode can be estimated, overall WDS-EBME of the MB concealed by each partition mode can then be evaluated and the best partition mode for the corrupted Macroblocks (MB) will be determined as the one with the smallest overall WDS-EBME. We also propose a progressive concealment order for the 4x4 partition mode. / In this thesis, techniques for efficient error resilient video coding are investigated. Three parts of the work are discussed in this thesis. / The last part of the thesis concerns the joint encoder-decoder error control method. A joint temporal error control method is proposed for H.264. It combines RDO-based macroblock (MB) classification at the encoder and adaptive partition size error concealment at the decoder. The encoder classifies the MBs by evaluating the sensitivity of the MBs as the RD cost between the concealment error and the bits needed for the additional motion information. Additional motion information such as the original motion vector or motion vector index can be transmitted for the error sensitive MBs. The decoder utilizes the additional motion information if any of these MBs get lost. Non-sensitive MBs and blocks are concealed by the APS method. / The second part of this thesis investigates encoder based error control techniques. Firstly, a VLC/FLC data partitioning method is proposed for MPEG-4. It disables intra AC prediction and groups appropriate fixed length coded (FLC) syntaxes in a video packet (or slice) together to form a new partition. With intra AC prediction disabled, errors occurring in these FLC syntaxes will not cause spatial error propagation. It essentially classifies the syntaxes into two categories according to whether that syntax will cause spatial error propagation when an error occurs. Secondly, a redundant macroblock strategy is proposed for H.264. MB Differential Mean Square Error (DMSE) is employed to evaluate the error sensitivity of MBs. The most sensitive MBs are transmitted separately in additional slices while coarsely quantized copies of the MBs are placed in the original slice. When working with chessboard style Flexible Macroblock reordering (FMO) and fixed length slice mode (FMO-slicing), the scheme performs well against packet loss errors with acceptable overhead and it is highly compatible with original H.264 bitstream. Thirdly, a joint optimal bit allocation and rate control scheme is proposed for H.264 with redundant slice. The optimum ratio between each primary and redundant picture pair is analytically deduced. Rate function and distortion model for both representations are developed, and a simple close-form solution is provided to achieve joint optimum bit allocation. / Video communication and other web-based video applications become popular in recent years. However, the transmission of the compressed video bit stream often suffers from imperfection of the communication channel, like path loss, multipath fading, co-channel interference, congestion, etc. Error resilient video coding techniques need to be employed to mitigate the channel errors, which include error concealment in the decoder, forward error correction in the encoder and joint encoder-decoder error control techniques. / Li, Jie. / Adviser: Ngan King Ngi. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 137-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

All multimedia devices now incorporate video CODECs that comply with international video coding standards such as H.264 / MPEG4-AVC and the new High Efficiency Video Coding Standard (HEVC) otherwise known as H.265. Although the standard CODECs have been designed to include algorithms with optimal efficiency, large number of coding parameters can be used to fine tune their operation, within known constraints of for e.g., available computational power, bandwidth, consumer QoS requirements, etc. With large number of such parameters involved, determining which parameters will play a significant role in providing optimal quality of service within given constraints is a further challenge that needs to be met. Further how to select the values of the significant parameters so that the CODEC performs optimally under the given constraints is a further important question to be answered. This thesis proposes a framework that uses machine learning algorithms to model the performance of a video CODEC based on the significant coding parameters. Means of modelling both the Encoder and Decoder performance is proposed. We define objective functions that can be used to model the performance related properties of a CODEC, i.e., video quality, bit-rate and CPU time. We show that these objective functions can be practically utilised in video Encoder/Decoder designs, in particular in their performance optimisation within given operational and practical constraints. A Multi-objective Optimisation framework based on Genetic Algorithms is thus proposed to optimise the performance of a video codec. The framework is designed to jointly minimize the CPU Time, Bit-rate and to maximize the quality of the compressed video stream. The thesis presents the use of this framework in the performance modelling and multi-objective optimisation of the most widely used video coding standard in practice at present, H.264 and the latest video coding standard, H.265/HEVC. When a communication network is used to transmit video, performance related parameters of the communication channel will impact the end-to-end performance of the video CODEC. Network delays and packet loss will impact the quality of the video that is received at the decoder via the communication channel, i.e., even if a video CODEC is optimally configured network conditions will make the experience sub-optimal. Given the above the thesis proposes a design, integration and testing of a novel approach to simulating a wired network and the use of UDP protocol for the transmission of video data. This network is subsequently used to simulate the impact of packet loss and network delays on optimally coded video based on the framework previously proposed for the modelling and optimisation of video CODECs. The quality of received video under different levels of packet loss and network delay is simulated, concluding the impact on transmitted video based on their content and features.

Abstract In this thesis, we consider the performance evaluation of peer-to-peer (P2P)streaming over wireless networks. Traditionally, P2P streaming has been implemented and analyzed extensively in wire line networks. As more and more devices are connected to the internet through wireless, however, it is critical to understand how wireless channel variability affects the performance of P2P systems. Weformulate the P2P streaming system as a queuing network, and analyze its performance based onthe large deviation principle. We are interested in characterizing the buffer underow probability, where users run of out content and cannot receive smooth video playback. As explicit analysis is very dicult with a nite number of users, we focus on characterizing the performance bounds when the number of users goes to innity, assuming that playback rate and buffer size both grow linearly with the number of users N. We show that the upper bound of buffer underow probability decays exponentially in N. We also compare the decay rate of bound in different channel models, and show that the Markov modulated channel leads to a faster decay rate than the I.I.D. model with the same expected channel capacities. / Leung, Kam Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 50-52). / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.2 / Chapter 1.1.1 --- Video Streaming --- p.2 / Chapter 1.1.2 --- Large Deviations Theory --- p.4 / Chapter 1.2 --- Related Works --- p.6 / Chapter 2 --- System Model and Assumptions --- p.9 / Chapter 2.1 --- System Model --- p.9 / Chapter 2.2 --- Assumptions --- p.11 / Chapter 2.3 --- Queuing Model --- p.12 / Chapter 3 --- Performance of Large Network --- p.16 / Chapter 3.1 --- Large Deviation Principle --- p.16 / Chapter 3.2 --- Time I.I.D. Channel Model --- p.23 / Chapter 3.3 --- Markov Modulated Channel --- p.29 / Chapter 3.4 --- Performance Comparison of Channel Model: Time I.I.D. Model vs Markov Modulated Model --- p.31 / Chapter 4 --- Simulation Result and Analysis. --- p.35 / Chapter 4.1 --- Simulation Settings --- p.35 / Chapter 4.2 --- The Performance Bounds of Different Playback Rates --- p.36 / Chapter 4.3 --- The Performance Bounds for Different Channel Transition Matrix --- p.37 / Chapter 5 --- Conclusion --- p.40 / Chapter A --- Appendix --- p.42 / Chapter A.1 --- Convexity of decay rate function for time I.I.D Model --- p.42 / Chapter A.2 --- Condition for the Chernoff Bound hold --- p.44 / Chapter A.3 --- Convergence of the Decay Rate Function --- p.44 / Chapter A.4 --- Moment Generating Function of Markov Modulated Sources --- p.46 / Chapter A.5 --- Limiting Probability Distribution of Capacity of Markov Channel --- p.47 / Chapter A.6 --- Computation: Capacity p.d.f of Two States Markov Modulated Channel --- p.48 / Bibliography --- p.50

No description available.

Wang, Yongzhi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p.68-72). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Abstract Model --- p.7 / Chapter 2.1 --- Request allocation problem --- p.7 / Chapter 2.2 --- Neighbor selection problem --- p.11 / Chapter 3 --- Simulation Model --- p.14 / Chapter 4 --- Load Balancing Algorithms --- p.18 / Chapter 4.1 --- Request allocation --- p.18 / Chapter 4.2 --- Neighbor selection algorithms --- p.24 / Chapter 4.2.1 --- What to measure? --- p.24 / Chapter 4.2.2 --- Timeout-based neighbor selection algorithms --- p.25 / Chapter 4.2.3 --- Periodic neighbor selection algorithms --- p.33 / Chapter 4.2.4 --- Comparison: Timeout-based versus Periodical neighbor selection algorithms --- p.39 / Chapter 4.3 --- Further experiments --- p.41 / Chapter 4.3.1 --- Request window size --- p.41 / Chapter 4.3.2 --- Impact of K --- p.42 / Chapter 4.3.3 --- Adaptive adjustment of the neighbor selection period --- p.43 / Chapter 4.3.4 --- Performance with adequate bandwidth --- p.45 / Chapter 5 --- Minimizing Server´ةs Load --- p.49 / Chapter 6 --- Background Study --- p.56 / Chapter 6.1 --- P2P content distribution system --- p.56 / Chapter 6.1.1 --- P2P File sharing system --- p.56 / Chapter 6.1.2 --- P2P streaming system --- p.59 / Chapter 6.1.3 --- P2P Video on Demand system --- p.61 / Chapter 6.2 --- Congestion control --- p.62 / Chapter 7 --- Conclusion --- p.67 / Bibliography --- p.68

Video game streaming has introduced to consumers a new method of creating branded content. Popular streaming platforms receive millions of broadcasters and viewers every month, and the current examines the influence of this type user-generated content on consumer attitudes and behaviors. The goal of this study is to understand how video game streams function as a marketing tool. To investigate this, a quantitative survey was designed and measured participants’ video gaming habits and their perceptions of credibility, usefulness of content, group identification, and purchase intention. Heavier gaming habits were found to be positively related to perceived credibility in a user-generated stream condition. Group identification and stream familiarity were found to be positively related to perceived credibility. These findings hold implications for using video game streams as a marketing tool, as heavier gamers were found perceive user-generated streams as a credible source of information.

This paper examines data from Spotify’s API for 2017-2018 to determine the effects of song attributes on the success of tracks on Spotify’s Top 200 Chart across five different countries: the U.S., Norway, Taiwan, Ecuador, and Costa Rica. Two dependent variables are used to measure the success of a song – a track’s peak position on the charts and the number of days it survives on a country’s Top 200 Chart. Using ten separate regressions, one for each dependent variable in all five countries, it is concluded that the presence of a featured guest on a track increases a song’s peak position and the number of days it survives on the charts in almost every country. Further, songs that are perceived as “happier” are more successful for both metrics in Norway and Taiwan while those that are louder and more aggressive have a shorter lifespan on the charts in three out of five of the countries studied. The paper concludes that further research should be conducted with a larger, more diverse dataset to see if these findings hold and if they are present in other countries as well.

Processing real-world data requires the ability to analyze data in real-time. Data processing engines like Hadoop come short when results are needed on the fly. Apache Spark's streaming library is increasingly becoming a popular choice as it can stream and analyze a significant amount of data. To showcase and assess the ability of Spark various metrics were designed and operated using data collected from the USGODAE data catalog. The latency of streaming in Apache Spark was measured and analyzed against many nodes in the cluster. Scalability was monitored by adding and removing nodes in the middle of a streaming job. Fault tolerance was verified by stopping nodes in the middle of a job and making sure that the job was rescheduled and completed on other node/s. A full stack application was designed that would automate data collection, data processing and visualizing the results. Google Maps API was used to visualize results by color coding the world map with values from various analytics.

Large classes that allow smaller amounts of instructor-student interaction have become more common in today's colleges. The best way to provide needed opportunities for students to overcome this lack of interaction with instructors remains unidentified. This research evaluated the use of video lecture capture (VLC) as a supplemental method for teacher-student interaction and what, if any, impact it and attendance have on student performance in large lecture courses. This ex post facto study conducted at a Northeastern research university utilized cognitive and andragogical frameworks to examine the relationships between the independent variables frequency of video viewing, quantity of videos viewed, and course attendance, as well as their impact on course performance in a large lecture course (N=329). Data sources included archival data from the learning management system and student survey responses. Analysis included a series of two-way ANOVA tests. The results indicated that the frequency of video viewing was found to have a significant positive effect on course performance (F = 3.018, p = .030). The number of VLC videos not viewed was also found to have a significant negative effect on course performance (F = 1.875, p = 0.016). Other independent variables were not found to have any significant main effect or interaction effect with the dependent variable, course performance. Findings from this research may be used by educators, students, and administrators planning course sizes and availability to better understand the relationship between these variables and how VLC can be used effectively in large lecture classes thus leading to improved efficacy in VLC use.

Voice over IP and video applications continue to increase the amount of traffic over the Internet. These applications utilize the UDP protocol because TCP is not suitable for streaming applications. The flow and congestion control mechanisms of TCP can change the connection transmission rate too drastically, affecting the user-perceived quality of the transmission. Also, the TCP protocol provides a level of reliability that may waste network resources, retransmitting packets that have no value. On the other hand, the use of end-to-end flow and congestion control mechanisms for streaming applications has been acknowledged as an important measure to ease or eliminate the unfairness problem that exist when TCP and UDP share the same congested bottleneck link. Actually, router-based and end-to-end solutions have been proposed to solve this problem. This thesis introduces a new end-to-end protocol based on TCP SACK called SF-SACK that promises to be smooth enough for streaming applications while implementing the known flow and congestion control mechanisms available in TCP. Through simulations, it is shown that in terms of smoothness the SF-SACK protocol is considerably better than TCP SACK and only slightly worse than TFRC. Regarding friendliness, SF-SACK is not completely fair to TCP but considerably fairer than UDP. Furthermore, if SF-SACK is used by both streaming and data-oriented applications, complete fairness is achieved. In addition, SF-SACK only needs sender side modifcations and it is simpler than TFRC.