Location based abstraction of user generated mobile videos

Demand for efficient ways to represent vast amount of video data has grown rapidly in recent years. The advances in positioning services have led to new possibilities in combining location information to video content. In this paper we present an automatic video editing system for geotagged mobile videos. In our solution the system creates automatically a video summary from a set of unedited video clips. Location information and timestamps are used to group video clips with the same context properties. The groups are used to create a video summary where subshots from same context group are represented as scenes. The novelty in our solution lies in combining geotags with low level content analysis tools in video abstraction. We have evaluated the created video summaries with a group of users and the system usability for service creation by building a semi-automatic web-based video editing service. The evaluations prove that our concept is useful as it improves coherence and enjoyability of the automatic video summaries.     

Metadata-driven multimedia access

With the growing ubiquity and mobility of multimedia-enabled devices, universal multimedia access (UMA) is emerging as one of the important components for the next generation of multimedia applications. The basic concept underlying UMA is universal or seamless access to multimedia content, by automatic selection and adaptation of content based on the user's environment. UMA promises an integration of these different perspectives into a new class of content adaptive applications that could allow users to access multimedia content without concern for specific coding formats, terminal capabilities, or network conditions. We discuss methods that support UMA and the tools provided by MPEG-7 to achieve this. We also discuss the inclusion of metadata in JPEG 2000 encoded images. We present these methods in the typical order that they may be used in an actual application. Therefore, we first discuss the (personalized) selection of desired content from all available content, followed by the organization of related variations of a single piece of content. Then, we discuss segmentation and summarization of audio video (AV) content, and finally, transcoding of AV content.     

Models for motion-based video indexing and retrieval

With the rapid proliferation of multimedia applications that require video data management, it is becoming more desirable to provide proper video data indexing techniques capable of representing the rich semantics in video data. In real-time applications, the need for efficient query processing is another reason for the use of such techniques. We present models that use the object motion information in order to characterize the events to allow subsequent retrieval. Algorithms for different spatiotemporal search cases in terms of spatial and temporal translation and scale invariance have been developed using various signal and image processing techniques. We have developed a prototype video search engine, PICTURESQUE (pictorial information and content transformation unified retrieval engine for spatiotemporal queries) to verify the proposed methods. Development of such technology will enable true multimedia search engines that will enable indexing and searching of the digital video data based on its true content.     

基于P2P流媒体的教学体系结构研究

随着网络通信和多媒体技术的发展,人们对网上音、视频的多媒体教学内容需求日益增长,基于流媒体技术的远程学习是未来人们受教育的新方法。然而流媒体的质量并不能令人满意,传统的网络教学系统大多采用C/S模式,服务器以单播的形式传输媒体流。结合当前流行的对等网络（P2P）技术和流媒体技术,介绍了如何构建基于P2P流媒体技术的远程网络教学系统的问题。结合P2P网络的优点,对系统中流媒体传输进行了改进,从而降低流媒体服务对骨干网的负载,避免网络阻塞。     

Editing out video editing

This article outlines a paradigm shift in media production: the advent of computational media production that will automate the capture, editing, and reuse of video content. By integrating metadata creation and (re)use throughout the media production process, we enable the mass customization of video.     

On-chip traffic modeling and synthesis for MPEG-2 video applications

The objective of this paper is to introduce self-similarity as a fundamental property exhibited by the bursty traffic between on-chip modules in typical MPEG-2 video applications. Statistical tests performed on relevant traces extracted from common video clips establish unequivocally the existence of self-similarity in video traffic. Using a generic tile-based communication architecture, we discuss the implications of our findings on on-chip buffer space allocation and present quantitative evaluations for typical video streams. We also describe a technique for synthetically generating traces having statistical properties similar to those obtained from real video clips. Our proposed technique speeds up buffer simulations, allows media system designers to explore architectures rapidly and use large media data benchmarks more efficiently. We believe that our findings open new directions of research with deep implications on some fundamental issues in on-chip networks design for multimedia applications.     

A playback schedule model for multimedia documents

Multimedia documents differ significantly from traditional documents composed of text and geometric graphics. The introduction of continuous media such as audio, video, and computer-generated graphics imposes new requirements on document representation and information storage. We designed an architecture for creating multimedia documents by means of a logical structure, a layout structure, and a rendering scenario, which is a schedule for document playback     

Synchronization properties in multimedia systems

Multimedia is defined as the integrated generation, representation, processing, storage, and dissemination of independent machine-processable information expressed in multiple time-dependent and time-independent media such as data, graphics, drawings, voice, audio, and video. The characteristics of synchronization mechanisms desirable for central and distributed multimedia systems are addressed. The concept of multimedia objects as components of an object-based model for a multimedia system is introduced. The essential new synchronization requirement is restricted blocking together with synchronization features covering real-time aspects. Existing synchronization mechanisms can be altered or new ones defined to meet these requirements     

基于视频摘要生成技术的研究

文章研究了标题形式摘要，故事板摘要及缩略视频摘要三种形式的摘要。充分利用各种多媒体融合分析手段，提出了视频内客判定模型。根据不同的视频分解粒度，提出了不同层次的对象重要度判定模型．生成有意义的视频摘要。设计实现了有效的视频摘要生成系统，融合多种技术与方法，形成完整的检索视频索引生成系统。     

音频—视频压缩技术

数字音频和视频的多种形式的信息通过各种媒体自由地传给我们，这是由于ＭＰＥＧ技术标准对音频－视频信息的压缩和在对目前的模拟媒体的数字化处理技术方面的改进产生的效果。文中给出了基本原理和ＭＰＥＧ委员会在ＭＰＥＧ－１和ＭＰＥＧ－２的标准发展中的活动，并且还包括为发展提供新功能的音频－视频信息编码模型的新标准的情况。     

Decomposing style,content, and motion for videos

In this paper, we present the first video decomposition framework, named SyCoMo, that factorizes a video into style, content, and motion. Such a fine-grained decomposition enables flexible video editing, and for the first time allows for tripartite video synthesis. SyCoMo is a unified and domain-agnostic learning framework which can process videos of various object categories without domain-specific design or supervision. Different from other motion decomposition work, SyCoMo derives motion from style-free content by isolating style from content in the first place. Content is organized into subchannels, each of which corresponds to an atomic motion. This design naturally forms an information bottleneck which facilitates a clean decomposition. Experiments show that SyCoMo decomposes videos of various categories into interpretable content subchannels and meaningful motion patterns. Ablation studies also show that deriving motion from style-free content makes the keypoints or landmarks of the object more accurate. We demonstrate the photorealistic quality of the novel tripartite video synthesis in addition to three bipartite synthesis tasks named as style, content, and motion transfer.     

MHEGAM-a multimedia messaging system

MHEGAM (MHEC-1 Advanced Mail) is a complete multimedia messaging system for the creation, exchange, and restitution of multimedia messages that express spatial and temporal synchronization among their components. MHEGAM can be based on the standard messaging systems X.420 or MIME. We present the multimedia extensions MHECAM-X.420 and MHEGAM-MIME and discuss the multimedia message format and architecture components for both systems     

Video representation with three-dimensional entities

Very low bit-rate coding requires new paradigms that go well beyond pixel- and frame-based video representations. We introduce a novel content-based video representation using tridimensional entities: textured object models and pose estimates. The multiproperty object models carry stochastic information about the shape and texture of each object present in the scene. The pose estimates define the position and orientation of the objects for each frame. This representation is compact. It provides alternative means for handling video by manipulating and compositing three-dimensional (3-D) entities. We call this representation tridimensional video compositing, or 3DVC for short. We present the 3DVC framework and describe the methods used to construct incrementally the object models and the pose estimates from unregistered noisy depth and texture measurements. We also describe a method for video frame reconstruction based on 3-D scene assembly, and discuss potential applications of 3DVC to video coding and content-based handling. 3DVC assumes that the objects in the scene are rigid and segmented. By assuming segmentation, we do not address the difficult questions of nonrigid segmentation and multiple object segmentation. In our experiments, segmentation is obtained via depth thresholding. It is important to notice that 3DVC is independent of the segmentation technique adopted. Experimental results with synthetic and real video sequences where compression ratios in the range of 1:150-1:2700 are achieved demonstrate the applicability of the proposed representation to very low bit-rate coding     

MPEG-Past and Future

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A joint signal processing and cryptographic approach to multimedia encryption.

In recent years, there has been an increasing trend for multimedia applications to use delegate service providers for content distribution, archiving, search, and retrieval. These delegate services have brought new challenges to the protection of multimedia content confidentiality. This paper discusses the importance and feasibility of applying a joint signal processing and cryptographic approach to multimedia encryption, in order to address the access control issues unique to multimedia applications. We propose two atomic encryption operations that can preserve standard compliance and are friendly to delegate processing. Quantitative analysis for these operations is presented to demonstrate that a good tradeoff can be made between security and bitrate overhead. In assisting the design and evaluation of media security systems, we also propose a set of multimedia-oriented security scores to quantify the security against approximation attacks and to complement the existing notion of generic data security. Using video as an example, we present a systematic study on how to strategically integrate different atomic operations to build a video encryption system. The resulting system can provide superior performance over both generic encryption and its simple adaptation to video in terms of a joint consideration of security, bitrate overhead, and friendliness to delegate processing.     

Video blogging: content to the max

The lure of video blogging combines the ubiquitous, grassroots, Web-based journaling of blogging with the richness of expression available in multimedia. Some claim that video blogging is an important force in a future world of video journalism and a powerful technical adjunct to our existing televised news sources. Others point to the huge demands it imposes on networking resources, the lack of hard standards, and the poor usability of current video blogging systems as indicators that it's doomed to fail. Like any nascent technology, video blogging has many unsolved problems. The field, however, is vibrant, the goals are fairly clear, and the challenges they pose to multimedia researchers are exciting indeed. Developing the standards and technologies for video blogging requires a combination of approaches from various areas including media representation, information retrieval, multimedia content analysis, and video summarization. Like the development of the Web and text blogging before, video blogging only come about through open development and collaboration between engineers and researchers from diverse fields. Most strikingly, it is fueled by the passion and enthusiasm of those creating content - those who go to the trouble of recording their lives and opinions within the fledgling medium, shaping it as a lively and useful resource for generations of Internet users to come.     

基于海思Hi3796M平台的新型乘客信息系统播放控制器设计研究

新型乘客信息系统(Passenger Information System,以下简称PIS系统)播放控制器设备的研发,基于海思Hi3796M平台上嵌入安卓系统,研发了轨道交通新型PIS播控器与新型PIS信息播控软件,通过MVC架构,实现了PIS系统视频流编辑与视频播放。通过车站现场实测,新型PIS播控器能够取代传统视频编辑播放设备,为PIS系统的稳定运行提供了技术保障。     

从MPEG压缩视频流中提取I帧的设计与实现

在基于视频内容的多媒体查询与检索系统中 ,经常希望用静态图像来表示视频内容 ,在视频点播中 ,有时需要视频服务器提供一种快进、快退的功能。提供了一种提取I帧的方法 ,并对PCR ,DTS ,PTS时间信息进行了讨论。