共查询到19条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
多媒体同步的Petri网模型 总被引:2,自引:0,他引:2
多媒休系统中通常包括各种媒休类型,例如,文本、语音、图象、音频和视频。保持和维护各种媒对象的同步关系是多媒体技术的一个重要研究领 相似文献
5.
6.
7.
扩展时间流Petri网多媒体同步模型 总被引:5,自引:0,他引:5
多媒体同步的一个主要问题是多媒体同步时间要求的描述与建模。文中基于时间流Petri网模型(TSPN),通过分析TSPN模型的不足之处,提出了一种新的多媒体同步模型--扩展时间流Petri网模型(STSPN),STSPN不但可以完全、准确地描述媒体流内和流间的时间行为,而且通过引入容许阻塞时间、问题算法等对TSPN进行扩展,可以有铲地克服网络随机延迟、阻塞和丢包等因素的不良影响,提高了模型的建模能力 相似文献
8.
基于时间Petri网的多媒体同步模型 总被引:1,自引:1,他引:1
多媒体同步是多媒体应用的一个重要需求,这已为众多研究人员所共识。多媒体同步的一个主要问题是多媒体同步时间需求的描述和建模。本文在克服当前多媒体同步模型局限性的基础上,提出了一个新的基于时间Petri网的多媒体同步模型--MSTP模型,它能使多媒体系统依据实际运行时的延迟和多媒体动脉同步类型。以更准确、高效的方式来保持多媒体同步。 相似文献
9.
10.
分布多媒体系统的多媒体动态同步模型 总被引:3,自引:1,他引:3
宋军 《计算机研究与发展》1998,35(5):431-435
在分布多媒体系统中,多媒体具有动态同步特性,同时关键媒体的同步要求在应用中享有优先权.现有的多媒体同步模型无法满足这些要求,现提出一个新的基于时间Petri网的多媒体动态同步模型——DSPN模型.它不仅能使分布多媒体系统依据实际运行状况和新提出的同步类型,以更准确、高效的方式来保持多媒体同步,而且允许用户对多媒体表现过程进行交互操作. 相似文献
11.
A model for specification and synchronization of data for distributed multimedia applications 总被引:1,自引:0,他引:1
As network technology provides the capability to handle multimedia traffic and the demand of multimedia services increases, protocols are required for effective communication of multimedia data in a distributed environment. Synchronization is one of the key issues in a multimedia system. Most of the current approaches do not support an integrated solution to the problem of synchronization. In this paper we propose a mechanism for synchronization of multimedia data in distributed environment where the accuracy of the protocol can be tailored to the application. The system model supports live and video-on-demand service. We present a scheme where the specification of the temporal requirements provided by the application can be directly mapped to obtain the information necessary to enforce the synchronization required. We present two examples of specifying the temporal requirements and process of obtaining the information and present performance results of our simulation studies. 相似文献
12.
Multimedia synchronization is the essential technology for the integration of multimedia in distributed multimedia systems.The multimedia synchronization model has been recognized by many researchers as a premise of the implementation of multimedia synchronization.In distributed multimedia systems,the characteristic of multimedia synchronization is dynamic,and the key medium has the priority in multimedia synchronization.The previously proposed multimedia synchronization models cannot meet these requirements.So a new multimedia dynamic synchronization model-DSPN,based on the timed Petri-net has been designed in this paper.This model can not only let the distributed multimedia system keep multimedia synchronization in a more precise and effective manner according to the runtime situation of the system,but also allow the user to interact with the presentation of multimedia. 相似文献
13.
14.
M. Bordegoni G. Faconti S. Feiner M.T. Maybury T. Rist S. Ruggieri P. Trahanias M. Wilson 《Computer Standards & Interfaces》1997,18(6-7):477-496
This article summarizes the main results of a joint endeavor towards a standard reference model (SRM) for intelligent multimedia presentation systems (IMMPSs). After a brief motivation, we give basic definitions for media terms and presentation systems. The core of this contribution is a generic reference architecture that reflects an implementation-independent view of the processes required for the generation of multimedia presentations. The reference architecture is described in terms of layers, components, and knowledge servers. Our SRM focuses on the functions assigned to the layers and components, rather than on the methods or communication protocols that may be employed to realize this functionality. Finally, we point to some possible extensions of the reference model. 相似文献
15.
车春回 《计算机工程与设计》2007,28(21):5163-5166
构造一个上下文敏感,具有可交互性的多媒体表示远比单纯构造视听信息或者单纯构造文本信息复杂得多.多媒体对象之间的交互需要有一个用来同步和异步交互的,包括立即响应的时空关系组织起来.根据构造环境的需要来考虑多媒体的结构构造.先通过介绍影响多媒体结构构造的7个要素来认识多媒体,然后在4种典型的构造模式中进行多媒体环境的选择.这4种构造模式分别是:结构化、时间关系、图关系、脚本形式.通过各种各样的观察和分析发现,结构化的多媒体构造为多媒体的表示提供了最为有效的表示形式. 相似文献
16.
17.
Ivan Herman Nuno Correia David A. Duce David J. Duke Graham J. Reynolds James Van Loo 《Multimedia Systems》1998,6(2):88-101
This paper describes an event-based synchronization mechanism, which is at the core of the inter-media synchronization in
the upcoming standard for multimedia presentation, PREMO. The synchronization mechanism of PREMO is a powerful tool, based
on a small number of concepts, and on cooperation among active objects, and represents a synthesis of various synchronization
models described in the literature. This model can serve as a basis for the implementation of complex synchronization patterns
in multimedia presentations, both purely event-based, as well as time-based. 相似文献
18.
多对象多媒体应用允许多路媒体同时呈现,其同步控制比较复杂,可分为传输过程中与呈现过程中的同步。然而现有的同步方法忽略了媒体在最后呈现过程中的同步,也没有考虑各媒体对象之间的同步要求差异。针对以上问题,为视频点播提出了一种在应用层上控制多对象多媒体同步呈现质量的方法。在采用多级缓冲门限实现媒体内同步反馈控制的基础上,依据主要媒体对象的呈现时间戳,在每一个呈现场景内调整次要媒体对象的呈现速率,从而实现媒体间的同步呈现。实验结果表明该方案能够有效地提高同步质量,且媒体间的同步性能平均提高28.45%。 相似文献
19.
本文提出了一种新的多媒体同步模型--交互式多媒体动态同步Petri网模型(IMDSPN)。IMDSPN能够准确地描述多媒体对象的各种同步时态关系,可以克服其表现过程中的同步失败问题,并可以保证在用户交互控制下同步关系的全局一致性,它有效地描述了多媒体的动态特性。 相似文献