Computer Engineering Commons^™

Voice And Video Capacity Of A Secure Wireless System, Jason R. Seyba

Theses and Dissertations

Improving the security and availability of secure wireless multimedia systems is the purpose of this thesis. Specifically, this thesis answered research questions about the capacity of wireless multimedia systems and how three variables relate to this capacity. The effects of securing the voice signal, real-time traffic originating foreign to a wireless local area network and use of an audio-only signal compared with a combined signal were all studied. The research questions were answered through a comprehensive literature review in addition to an experiment which had thirty-six subjects using a secure wireless multimedia system which was developed as part of this …

A Review Study On Digital Watermarking, Jian Liu, Xiangjian He

International Conference on Information and Communication Technologies

There has been a rapid development in the growth of multimedia and communications in the past few years. With the widespread use of the networks, intellectual properties can be obtained, reproduced or redistributed easily. This creates a high demand for content protection techniques. Watermarking, one of the most efficient ways to protect the digital properties has won more and more concern in recent years. This paper reviews several aspects about digital watermarking. Among them, we mainly focus on three processes of digital watermarking. Also, we will examine the properties of watermarking and several applications of watermarking. At last, this paper …

Online Multimedia Communication System, Yin-Wei Yang

Theses Digitization Project

Online Multimedia Communication System is a project aimed at providing people the ability to store and share their multimedia files. The users and administrator can modify and view the files and database information from a normal web browser. Furthermore, this site offers a secure environment to keep all the users' information private.

Using Dynamic Optimization For Control Of Real Rate Cpu Resource Management Applications, Varin Vahia, Ashvin Goel, David Steere, Jonathan Walpole, Molly H. Shor

Computer Science Faculty Publications and Presentations

In this paper we design a proportional-period optimal controller for allocating CPU to real rate multimedia applications on a general-purpose computer system. We model this computer system problem in to state space form. We design a controller based on dynamic optimization LQR tracking techniques to minimize short term and long term time deviation from the current time stamp and also CPU usage. Preliminary results on an experimental set up are encouraging.

Adaptive Live Video Streaming By Priority Drop, Jie Huang, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we explore the use of Priority-progress streaming (PPS) for video surveillance applications. PPS is an adaptive streaming technique for the delivery of continuous media over variable bit-rate channels. It is based on the simple idea of reordering media components within a time window into priority order before transmission. The main concern when using PPS for live video streaming is the time delay introduced by reordering. In this paper we describe how PPS can be extended to support live streaming and show that the delay inherent in the approach can be tuned to satisfy a wide range of …

Supporting Low-Latency Tcp-Based Media Streams, Ashvin Goel, Charles Krasic, Kang Li, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The dominance of the TCP protocol on the Internet and its success in maintaining Internet stability has led to several TCP-based stored media-streaming approaches. The success of these approaches raises the question whether TCP can be used for low-latency streaming. Low latency streaming allows responsive control operations for media streaming and can make interactive applications feasible. We examined adapting the TCP send buffer size based on TCP's congestion window to reduce application perceived network latency. Our results show that this simple idea significantly improves the number of packets that can be delivered within 200 ms and 500 ms thresholds.

Thread Transparency In Information Flow Middleware, Rainer Koster, Andrew P. Black, Jie Huang, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

Existing middleware is based on control-flow centric interaction models such as remote method invocations, poorly matching the structure of applications that process continuous information flows. Difficulties cultiesin building this kind of application on conventional platforms include flow-specific concurrency and timing requirements, necessitating explicit management of threads, synchronization, and timing by the application programmer. We propose Infopipes as a high-level abstraction for information flows, and we are developing a middleware framework that supports this abstraction. Infopipes transparently handle complexities associated with control flow and multi-threading. From high-level configuration descriptions the platform determines what parts of a pipeline require separate threads or …

Reifying Communication At The Application Level, Andrew P. Black, Jie Huang, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Middleware, from the earliest RPC systems to recent Object-Oriented Remote Message Sending (RMS) systems such as Java RMI and CORBA, claims transparency as one of its main attributes. Coulouris et al. define transparency as “the concealment from the … application programmer of the separation of components in a distributed system.” They go on to identify eight different kinds of transparency.

We considered titling this paper “Transparency Considered Harmful”, but that title is misleading because it implies that all kinds of transparency are bad. This is not our view. Rather, we believe that the choice of which transparencies should be offered …

Vlsi Implementation Of A Massively Parallel Wavelet Based Zerotree Coder For The Intelligent Pixel Array, Geoffrey N. Alagoda

Theses: Doctorates and Masters

In the span of a few years, mobile multimedia communication has rapidly become a significant area of research and development constantly challenging boundaries on a variety of technologic fronts. Mobile video communications in particular encompasses a number of technical hurdles that generally steer technological advancements towards devices that are low in complexity, low in power usage yet perform the given task efficiently. Devices of this nature have been made available through the use of massively parallel processing arrays such as the Intelligent Pixel Processing Array. The Intelligent Pixel Processing array is a novel concept that integrates a parallel image capture …

Aspects Of Information Flow, Andrew P. Black, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Along with our colleagues at the Oregon Graduate Institute and Georgia Institute of Technology, we have recently been experimenting with real-rate systems, that is, systems that are required to move data from one place to another at defined rates, such as 30 items per second. Audio conferencing or streaming video systems are typical: they are required to deliver video or audio frames from a source (a server or file system) in one place to a sink (a display or a sound generator) in another; the frames must arrive periodically, with constrained latency and jitter. We have successfully built such systems …

Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Applications with real-rate progress requirements, such as mediastreaming systems, are difficult to deploy in shared heterogenous environments such as the Internet. On the Internet, mediastreaming systems must be capable of trading off resource requirements against the quality of the media streams they deliver, in order to match wide-ranging dynamic variations in bandwidth between servers and clients. Since quality requirements tend to be user- and task-specific, mechanisms for capturing quality of service requirements and mapping them to appropriate resource-level adaptation policies are required. In this paper, we describe a general approach for automatically mapping user-level quality of service specifications onto resource …

Feedback Based Dynamic Proportion Allocation For Disk I/O, Dan Revel, Dylan Mcnamee, Calton Pu, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we propose to use feedback control to automatically allocate disk bandwidth in order to match the rate of disk I/O to the real-rate needs of applications. We describe a model for adaptive resource management based on measuring the relative progress of stages in a producer-consumer pipeline. We show how to use prefetching to transform a passive disk into an active data producer whose progress can be controlled via feedback. Our progress-based framework allows the integrated control of multiple resources. The resulting system automatically adapts to varying application rates as well as to varying device latencies.

Multiple Streams Synchronization In Collaborative Multimedia Systems, Emilia Stoica

Computer Science Theses & Dissertations

With the recent increase of the communication bandwidth and processor power, new types of applications have emerged. Among them, there are multimedia application, in which users are able to control, combine, and manipulate different types of media, such as text, sound, video, computer graphics, and animation. A key requirement in any multimedia application is to synchronize the delivery of various media streams to the user. To achieve this, the sender has to provide the temporal relations between the streams as they are captured. Since the receiver uses this information in streams presentation, its accuracy is very important.

Our main contribution …

Flow And Congestion Control For Internet Streaming Applications, Shanwei Cen, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The emergence of streaming multimedia players provides users with low latency audio and video content over the Internet. Providing high-quality, best-effort, real-time multimedia content requires adaptive delivery schemes that fairly share the available network bandwidth with reliable data protocols such as TCP. This paper proposes a new flow and congestion control scheme, SCP (Streaming Control Protocol) , for real-time streaming of continuous multimedia data across the Internet. The design of SCP arose from several years of experience in building and using adaptive real-time streaming video players. SCP addresses two issues associated with real-time streaming. First, it uses a congestion control …

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Script-Based Qos Specifications For Multimedia Presentations, Richard Staehli, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Multimedia presentations can convey information not only by the sequence of events but by their timing. The correctness of such presentations thus depends on the timing of events as well as their sequence and content. This paper introduces a formal specification language for playback of real-time presentations. The main contribution of this language is a quality of service (QOS) specification that relaxes resolution and synchronization requirements for playback. Our definitions give a precise meaning to the correctness of a presentation. This specification language will form the basis for a QOS interface for reservation of operating system resources.