KEYWORDS: Video, Televisions, Error analysis, Digital video recorders, Computer simulations, Computer programming, Multimedia, Computer science, Systems modeling, Internet
A model for evaluating the effectiveness of automatic recording of television programs by digital personal video recorders (PVRs) is presented. The model is used to evaluate the tradeoff between manual management of recording programs to a PVR archive and automatic management of recording. We show that a tradeoff exists between manual management in which the utility of a program is perfectly known but user awareness of available programs is limited versus
automatic management in which utility estimates contain error but awareness is perfect. Experiments with the model show that the shape of this tradeoff is most governed by the shape of the distribution of user utility. As the percentage of programs with high user utility decreases relative to the average, the more effective automatic recording is likely to be despite errors in utility estimation. The shape of this tradeoff, however, is highly inelastic. Thus, improving utility estimates will not make automatic recording more effective if user awareness is sufficiently high.
Live Internet streaming media programs, called webcasts, can adopt techniques developed by television to obtain higher quality. We have developed a general webcast production model composed of three stages (i.e., sources, broadcast, and transmission) and a tool, called the Director's Console (dc), to control live webcasts. The tool is one component of a distributed service architecture, which adapts to varying physical infrastructure and broadcast configurations.
Video effects play an important role in adding production value to video progress. The use of video effects with Internet Video sources, however, is still uncommon because traditional hardware-based solutions are poorly suited to the Internet environment. In previous work, we describe a parallel, software-only video effects system designed for Internet Video and explored the use of temporal parallelism. This paper explores the use of spatial parallelism. In particular, an intermediate semicompressed video format is described that was designed to exploit spatial parallelism, and performance measurements are reported on the use of this representation.
In this paper, we describe the design and implementation of a prototype software video production switcher, vps, that improves the quality of the content of MBone broadcasts. vps is modeled after the broadcast television industry's studio production switcher. It provides special effects processing to incorporate audience discussions, add titles and other information, and integrate stored videos into the presentation. vps is structured to work with other MBone conferencing tools. The ultimate goal is to automate the production of MBone broadcasts.
KEYWORDS: Video, Data modeling, Curium, Computer programming, Video processing, Process modeling, Multimedia, Adaptive control, Optical filters, Video compression
The design and performance of the Berkeley Continuous Media Toolkit (CMT) is described. CMT provides a programming environment for rapid development of continuous media applications. CMT overhead is measured in the context of a simple video playback application and is found to be only a few milliseconds per frame played. As a demonstration of CMT as a research infrastructure, an experiment comparing adaptive frame rate control policies is described.
KEYWORDS: Video, Curium, Video processing, Adaptive control, Clocks, Software development, Video compression, Internet, Process control, Control systems
A software decoder for MPEG-1 video was integrated into a continuous media playback system that supports synchronized playing of audio and video data stored on a file server. The MPEG-1 video playback system supports forward and backward play at variable speeds and random positioning. Sending and receiving side heuristics are described that adapt to frame drops due to network load and the available decoding capability of the client workstation. A series of experiments show that the playback system adds a small overhead to the stand alone software decoder and that playback is smooth when all frames or very few frames can be decoded. Between these extremes, the system behaves reasonably but can still be improved.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.