Principles of delay-sensitive multimedia data storage retrieval

Multimedia Computing and Networking 1996, 1996

A number of applications require audio and video data. Access to such data requires continuous real{time stream ow during playback(recording). This requires scheduling accesses to storage devices for such data. The high volume of such streams, especially video, makes it neccessary to store them using compression schemes like JPEG and MPEG. However, doing so introduces playback data rate variability which in turn leads to poor storage system utilization if playback guarantees are to be maintained. Not all applications require perfect playback, and some tardiness and discontinuity during playback, within limits of acceptable Quality of Service (QoS), is tolerated. In this paper we brie y describe solutions to two problems that arise in scheduling the retrieval of compressed streams from secondary storage. Firstly, we propose QBSCAN, a scheme which reserves I/O bandwidth based on statistical estimates of playback rate in order to improve utilization. This is achieved by incorporating the QoS which comprises the playback rate (in frames per second), the maximum (consecutive) skipped frames, and the mean time between frame skips. Secondly, we develop storage techniques speci cally designed for MPEG video, to be used in conjunction with QBSCAN, that allows robust playback. This is a problem because MPEG encoding introduces inter frame dependencies which make it hard to drop frames arbitrarily. Thus, the objectives of QBSCAN are to maximize the storage system utilization, and minimize bu er requirement, while providing the needed QoS despite data rate variability and dependency. Simulation studies are used to validate the e cacy of the proposed techniques.

Selected Areas in Communications, …, 1990

Multimedia computer systems are required to store, retrieve, and communicate objects comprised of mixed data types including images, text and voice. An important aspect of multimedia systems is the integration of elements retrieved from databases distributed across a network. Integration of object components requires consideration of the temporal characteristics of multimedia elements.

1997

Due to the fact that the speeds of secondary storage devices have not improved relative to other computing technologies, a lot of efforts have been devoted to intelligent and efficient ways of storing data of storing data to maximixe the bandwidth of a computing system. Many of those techniques have proven useful; however, with the advent of multimedia and its enormous real-time and size requirements, the problems of data allocation and retrieval have become even more crucial. In [1][2], we describe some designs of efficient multimedia object storage strategies that strive to allocate multimedia objects with the objective of satisfying their real-time retrieval requirements. We utilize some fragmentation strategies, a cost function, and bipartite graph model to allocate multimedia data efficiently. In the development of the storage allocation strategies, some assumptions were made about the functionalities and capabilities of the controlling Multimedia Object Manager. Here, we describe...

Proceedings of the second ACM international conference on Multimedia - MULTIMEDIA '94, 1994

The past decade has witnessed a proliferation of personal computers at homes, businesses, cl-rooms, libraries, etc. Most often, thene systems are used to disseminate information. Recently, multimedia repositories have added to the excitement of this information age by allowing a user to retrieve and manipulate continuous media data types (audio and video objects). The design and implementation of these systems is challenging due to both the large size of objects that constitute this media type and their continuous bandwidth requirement. Compression in combination with the availability of fast CPUS (for real-time decompression) pro vide effective support for a continuous display of those ob jects with a high bandwidth requirement. Hierarchical storage structures (consisting of RAM, disk and tertiary storage devices) provide a cost-effective solution for the large size of their repositories. The focus of this study is on personal computers (single user, single display) that employ fast CPUS, compression, and hierarchical storage structures to support multimedia applications. Its goals are to ensure a continuous display of audio and video objects while minimizing the latency time observed by the user. Its contributions include a novel pipelining mechanism and PIRATE as a technique to manage the disk resident objects.

International journal of engineering research and technology, 2018

In the last few years extensive request for user oriented multimedia information systems has developed.Multimedia database can be defined as a pool of storage and retrieval systems, in which large amount of media objects are created, searched, modifiedand retrieved. Multimedia is the combination of text, image, graphicsand animations, audio and video information. The addition of database application to handle multimedia objects requires organization of multiple media data streams. Apart from text retrieval, the current waves in web searching and multimedia documents retrieval are the exploration for and supply of images, audio, 3D extracts and video. The content-based multimedia information retrieval offers new techniques and methods for probing various multimedia databases over the world.The discussiondeals with a new standard for multimedia search based on content. Keywords— Multimedia database;content based retrivel; text based retrival; free browsing;CAS;

Database Systems for Advanced Applications '97, 1997

This paper presents a unified approach to modeling and implementing temporal multimedia objects. The approach is based on both the object-orientation and the time interval logic investigated by Allen /Alle83]. We regard every temporal multimedia data as a time interval. Then, by introducing null time-intervals, it is shown tha& every temporal relafionship is represented using only the equals and the meets relationship. Accordingly, to manipulate heterogeneous temporal multimedia data in a unified manner, normal forms of composite temporal multimedia objects are introduced. The normal forms allow us to implement a multimedia player, where two synchronization schemes are necessary and sufjicient to play back any composite temporal object; which are the individual and the start synchronization scheme. These schemes are implemented and evaluation results are shown in thispaper. In general, audiovisual d&a are huge. We adopted MPEG-I standard to compress video data. A suitable storage structure for MPEG-I video data is also shown with a class hierarchy.

2003

Multimedia data, such as text, audio, images and video, is rapidly evolving as the main form for the creation, exchange, and storage of information in the modern era. Primarily, this is attributed to rapid advances in the three major technologies that determine its growth: VLSI technology that is producing greater processing power; broad-band networks (ISDN, ATM, etc) that are providing much higher bandwidth for many practical applications, and multimedia compression standards (JPEG, H.

2003

Lately, on-demand streaming multimedia applications have become very popular. Contemporary personal computers can handle the load imposed by such multimedia applications on the client side, but the potentially high number of concurrent users accessing a server represents a generic problem. The multimedia storage system is responsible for storage and retrieval of multimedia data from storage devices, and plays a vital role for the performance and scalability of multimedia servers. It deals with issues related to data placement, scheduling, file management, continuous data delivery, buffer management, prefetching, etc., and with the particular demands of multimedia applications, such as real-time characteristics, large file sizes, high data rates, and several data sources. Performing these tasks and supporting these requirements appropriately are burdened by an increasing speed mismatch between processors and the most prolific and affordable storage devices,-magnetic disks-, and by the introduction of new requirements in new multimedia scenarios. In this article, we give a survey of storage system support for continuous media applications and discuss issues related to integration of different mechanisms for the future multimedia storage systems.

It is now common for multimedia applications to be partitioned and mapped onto multiple processing elements of a system-on-chip architecture. An important design constraint in such architectures is that the FIFO buffers connecting the processing elements (in a pipelined fashion) should not overflow and the playout buffer should never underflow. To meet these constraints, an usual design practice is to increase the initial playout delay after which the output device starts reading from the playout buffer. Although implementing this technique is straightforward and involves only the the computation of an appropriate playout delay, it suffers from the downside of a large playout buffer being required. In this paper, instead of associating the playout delay solely with the output device , we propose to redistribute this delay among all the processing elements running the various tasks of the multimedia application. We show that this delay redistribution technique can signficantly reduce (up to 70%) the total on-chip memory required.

Due to the explosive growth of the internet and increasing demand for multimedia information on the web, streaming video over the Internet has received tremendous attention from academia and industry. Continuous media has a lot of issues and challenges. The most important among of them are delay. Delay is an expression of how much time it takes for a packet of data to get from one point to another. Some of delay source are fixed while the other is not. This paper describes the delay sources and magnitude of the most common video codecs and thus provides a guideline for the choice of the most suitable codec for a given application.