基于TCPMP的CMMB交互应用播放器设计与实现

介绍一种以开源多媒体播放器TCPMP为基础框架,面向中国移动多媒体广播(CMMB)双向交互业务的播放器方案设计。该播放器不仅能实现实时接收播放、录制CMMB节目等基本功能,还可以作为终端通过电信网或互联网与头端系统进行交互,包括在线点播、文件下载播放、数字版权管理加密节目的客户端播放权限认证执行等应用,支持CMMB和多种流行的媒体内容格式。     

Windows Media流媒体格式ASF的研究

ASF文件是Microsoft公司Windows Media Technology信息流式播放方案的核心,也是远程教育中使用较多的多媒体格式,ASF文件在逻辑上由头对象,数据对象和索引对象构成。文章详细分析了ASF文件格式,通过图解的方式介绍了ASF文件的解析流程和ASF格式数据传输方式,实现了基于Windows Media流媒体实时传输系统,并给出了ASF流格式服务器端和客户端的实现方法。     

Visual FoxPro中的多媒体编程

对VisualFoxPro多媒体编程中MultimediaMCI控件和若干API函数的使用方法进行了讨论,给出了应用示例。MultimediaMCI控件为多媒体文件的播放提供了一个标准界面。API函数中的PlaySound/sndPlaysound函数可用于小型wav文件播放。mciExecute函数、mciSengString函数可以播放多种格式音频和avi视频文件,功能更强大,可以提供程序员更多的发挥空间。     

基于EM8620L的嵌入式多媒体播放终端设计

采用专用多媒体视音频解码芯片EM8620L为核心，设计了一种新型的多媒体播放终端，它能够播放多种格式的多媒体文件。其硬件主要由专用解码芯片、网络控制电路、存储器和显示控制电路组成，软件系统由操作系统、图形系统和应用程序组成。通过调试证明该方案合理、先进，为视频联网广告系统提供了一种功能强大的、智能化的播放终端。     

Visual FoxPro中的多媒体编程

对Visual FoxPro多媒体编程中Multimedia MCI控件和若干API函数的使用方法进行了讨论，给出了应用示例。Multimedia MCI控件为多媒体文件的播放提供了一个标准界面。API函数中的P1aySound／sndPlaysound函数可用于小型wav文件播放。mciExecute函数、mciSengString函数可以播放多种格式音频和avi视频文件，功能更强大，可以提供程序员更多的发挥空间。     

基于AES的Flash加密实现

目前随着Flash成为网络多媒体的主流,相关的破解软件和加密软件也越来越多,部分破解软件不仅可以查看swf里面的相关脚本代码,还可以将swf格式的文件还原成Fla格式。加密器就是针对现状基于AES加密方式对swf文件进行整体加密,防止反编译软件的攻击。     

用Win32汇编语言对PE格式的EXE文件进行口令加密

介绍了用Win32汇编对PE格式EXE文件进行口令加密的基本原理和方法,并给出了实用的加密代码,对研究文件的加密很有参考价值。     

对SWF文件实现加密保护

SWF是一种格式公开的文件格式,只要照着格式说明书诸字节的分析,或者通过反编译软件,就可以获取SWF文件中的信息。为使SWF文件不受侵权,保护文件作者的合法权益,本文分析了现在市场上存在的加密软件Flashincrypt、SWFEncrypt和DoSWF的优缺点,并提出了软件组合加密方法。     

dBASEⅢDBF库文件的一种简易加密

目前dbaseⅢ在管理领域中得到了广泛的应用,有时出于某种原因,需要对dbaseⅢ的dbf库文件进行加密,本文将提供一种简易加密方法。一、为了加密先要了解dbaseⅢ的dbf库文件的内部存贮格式,它由结构说明和数据两部分组成。(见库文件结构图)     

Windows Media流媒体格式ASF的研究

ASF文件是Microsoft公司Windows Media Technology信息流式播放方案的核心,也是远程教育中使用较多的多媒体格式,ASF文件在逻辑上由头对象、数据对象和索引对象构成。文章详细分析了ASF文件格式,通过图解的方式介绍了ASF文件的解析流程和ASF格式数据传输方式,最后实现了基于Windows Media流媒体实时传输系统,并给出了ASF流格式服务器端和客户端的实现方法。ASF文件的数据传输速率可以在28．8kb／s到3Mb／s之间变化,用户可以根据自己应用环境和网络条件选择合适的速率,实现VOD点播和实时直播,在解决好流媒体同步的基础上可实现远程教育,具有较大的应用和发展潜力。     

一种文件智能加密方法研究

经典的文件加密算法（如AES等）有一个特点,即加密后的文件是乱码。这极容易被攻击者识别,进而实施暴力破解或干脆破坏文件。本文就这一问题,尝试根据文件的不同格式对文件进行智能加解密,在保证对文件重要数据进行加密的基础上,不破坏文件甚至是文件数据的原有格式,目标是使攻击者难以识别该文件是加密后文件,以达到更好的数据保护的目的。     

Soft multimedia anomaly detection based on neural network and optimization driven support vector machine

Software multimedia anomaly detection model based on neural network and optimization driven support vector machine is discussed in this paper. For multimedia information, most traditional information security technology has its limitations. For example, the limitation of the encryption technology is that on the one hand, the encrypted files resulting from the incomprehension of attributes interfere with the transfer of multimedia information. On the other hand, the encrypted multimedia information is likely to attract the attacker’s curiosity and attention, and is likely to be cracked, and once it is cracked, the system loses control of the information. To deal with these challenges, this study integrates soft computing techniques to finalize the enhanced multimedia anomaly detection model. With respect to the neural network, a random system with random factors is referred to as a random system. These practical systems are generally described and modeled by stochastic differential equations. In this study, we combined the double support vector machine and decision tree support vector machine to construct a new double support vector machine decision tree classifier. Kernel function and convex optimization were integrated to guarantee an optimal solution. Experimental results demonstrated the robustness of the model compared with other recent techniques.

     

Multimedia file forensics system exploiting file similarity search

With the fast increase of multimedia contents, efficient forensics investigation methods for multimedia files have been required. In multimedia files, the similarity means that the identical media (audio and video) data are existing among multimedia files. This paper proposes an efficient multimedia file forensics system based on file similarity search of video contents. The proposed system needs two key techniques. First is a media-aware information detection technique. The first critical step for the similarity search is to find the meaningful keyframes or key sequences in the shots through a multimedia file, in order to recognize altered files from the same source file. Second is a video fingerprint-based technique (VFB) for file similarity search. The byte for byte comparison is an inefficient similarity searching method for large files such as multimedia. The VFB technique is an efficient method to extract video features from the large multimedia files. It also provides an independent media-aware identification method for detecting alterations to the source video file (e.g., frame rates, resolutions, and formats, etc.). In this paper, we focus on two key challenges: to generate robust video fingerprints by finding meaningful boundaries of a multimedia file, and to measure video similarity by using fingerprint-based matching. Our evaluation shows that the proposed system is possible to apply to realistic multimedia file forensics tools.

     

Genetic fingerprinting for copyright protection of multicast media

Generally speaking, comparing to the unicast or broadcast methods, it is more efficient to transmit multimedia data via the multicast method to massive users. However, the ease of delivery of multimedia data may cause the copyright of such multimedia to be easily infringed upon, and the fingerprinting scheme is one of effective means for conquering this problem. Fingerprint embedding process often generates the multimedia contents into many different versions, which have to be transmitted via the unicast method. In this paper, we propose a new genetic fingerprinting scheme for copyright protection of multicast video. In this method, the encryption and decryption keys, which aim at scrambling and descrambling multimedia contents, are first produced with genetic algorithms. Next, multimedia data are then encrypted and multicast to all users. At the same time, a secure channel is employed to unicast a designated decryption key to each user. When a user deploys the designated key to decrypt the received data, a corresponding fingerprint would be embedded into the contents. Once upon the reception of the fingerprinted multimedia content, the embedded fingerprint can be extracted shortly, and the copyright can be confirmed and assured. Experimental results demonstrate that the proposed method can transmit multimedia data to clients effectively and cause only a slight degradation in perceptual quality.     

一种基于文件过滤驱动的Windows文件安全保护方案

针对提高文件安全级别需要较高安全成本问题,提出了一种低成本高安全的Windows文件保护方法。该方法采用Windows NT驱动框架,基于文件系统过滤驱动技术实现对文件进行透明加解密。文件内容用快速的对称算法加密,并且一文件一密钥。文件密钥用安全性更高的非对称算法加密,加密密钥保存于专用密钥文件中,用户私钥存放在密钥U盘里。在此基础上,提出了一种文件安全共享的方法。分析和应用表明,该方案在增加较少硬件成本基础上,可有效保护存储设备遗失或被盗、管理员密码被破解、文件共享时的文件安全。     

基于NTFS的文件加密系统

NTFS提供了一种称为加密文件系统的功能,这和功能使用户可以对自己的文件进行加密,以防止其内容暴露作入侵者面前。用户在使用这个功能的过程中,一方面会遇到自己加密的文件无法恢复的情况,另一方面是自己加密的文件被入侵者窃取,并查看其内容。本文讨论了文件加密的概念,加密解密过程,使用教程中的常见问题以及加密文件系统的安全性。     

A study on multimedia file carving method

File carving is a method that recovers files at unallocated space without any file information and used to recover data and execute a digital forensic investigation. In general, the file carving recovers files using the inherent header and footer in files or the entire file size determined in the file header. The largely used multimedia files, such as AVI, WAV, and MP3, can be exactly recovered using an internal format in files as they are continuously allocated. In the case of the NTFS, which is one of the most widely used file system, it supports an internal data compression function itself, but the NTFS compression function has not been considered in file carving. Thus, a large part of file carving tools cannot recover NTFS compressed files. Also, for carving the multimedia files compressed by the NTFS, a recovery method for such NTFS compressed files is required. In this study, we propose a carving method for multimedia files and represent a recovery plan for deleted NTFS compressed files. In addition, we propose a way to apply such a recovery method to the carving of multimedia files.     

视频转码技术在网络多媒体传输中的应用

视频文件数据量大、网络带宽有限,针对这一特点,提出了一种将视频文件进行转换为低码率的MPEG-4格式的文件后分帧传输的方案。在实际工程中表明基于该方案设计的采用视频转码技术的网络多媒体传输系统可以使传输效率提高5~10倍。文中重点对方案中涉及的压缩转码过程进行了讨论分析,根据分析给出了在压缩编码过程中涉及到的一些参数,并进一步指出了视频转换编码模块的灵活性。     

DRM系统中数字水印技术的研究

随着计算机网络的快速发展，越来越多的高品质的数字媒体文件在互联网上进行发布和流传。而越来越多的未经授权的媒体文件的出现，将极大地损害版权所有人的利益。将数字水印技术应用于数字版权的管理（DRM）中，可加强数字化音视频产品的内容保护。文章结合传统密码保护技术，首先通过应用实值混沌序列对水印图像信息进行置乱加密，然后嵌入数字音频信息的DCT域中，最后使用系统密钥对秘密信息逆置乱还原出原始信息。仿真实验说明该方法具有较好的不可察觉性。     

基于可信计算平台的加密文件系统

普通的加密文件系统能够对文件内容进行安全保护,加密文件与密钥被绑定在一起。但是,密钥仅仅通过弱口令来进行安全保护,这对系统来说是一个安全隐患,因此密钥保护是迫切需要解决的问题.通过运用TPM密钥树对整个文件系统中的密钥进行加密保护,将加密密钥同TPM所在平台进行绑定,从而实现密钥的安全保护,增强了整个系统的安全性。通过采用基于HMAC的数据检验,在保证安全性的同时,又提高了完整性校验的性能。