数字传输

The method includes steps: digital watermark technique is adopted to hide information of key data in not key data codes of compressed image; under protection of digital watermark, using protective backup for key data detects whether normal transmitted key data is correct or not so as to detect error code; carrying out cyclic mutual backup by using macro blocks in same positions in front and back macro block set; embedding coded motion vector in form of digital watermark to DCT transformation coefficient, and ensuring that video data are not influenced as best as one can; when error code occurs, if key data backup is correct, then the backup replaces former key data; otherwise, using mean value of key data in adjacent macro blocks within same frame to replace former key data approximately.

本发明中，采用数字水印技术在压缩图像的非关键数据编码中隐藏关键数据信息；通过数字水印保护下的关键数据保护备份来检测正常传输的关键数据是否正确，由此来检测传输误码；用前后宏块组中相同位置的宏块进行循环相互备份；对运动向量进行编码，然后以数字水印的形式嵌入到相对不重要的DCT变换系数中，同时保证视频数据尽量不受影响；在误码发生时，如果关键数据备份正确，则直接替代原关键数据，否则用同一帧内相邻宏块的关键数据的平均值近似替代原关键数据。

Digital audio - Digital input-output interfacing - Transmission of digital audio over asynchronous transfer mode networks

数字音频。数字输入输出接口。异步传输模式网络上的数字音频传输

In order to improve the transmission quality and reliability of the digital communication system, channel coding is proposed.

详细说明：为了改善数字通信系统的传输质量，提高数字通信系统传输的可靠性引入信道编码。

This implementation is based on AHB bus, it can demultiplex the transport steam with some different ways(the demultiplex process can be divided into some steps,the steam can be picked up from one of the steps).

这种实现方式是基于AHB总线的基础上，是SOC片上系统芯片中的一个子模块，可以灵活实现多种模式解析数字电视传输流，即将数字电视传输流解复用分为几个步骤，根据需要能够提取解析中不同阶段的码流。

Since the signal equipments imported is unable to meet the development demand of urban rail transit, independent research of the domestic digital jointless track circuit is critical. Charateristic analysis for signal transmission of digital jointless track circuit was mainly studied in this thesis. Design digital jointless track circuit analysis software, which validated the transmission parameters could or not meet requirements of the normal, shunt and signaling states, was the key work of the research.

本文在我国引进的国外信号设备无法满足国内城市轨道交通发展的需求，并自主研发出国产化试验型数字轨道电路的背景下，对数字无绝缘轨道电路信号传输进行特性分析，并设计出数字无绝缘轨道电路分析软件，实现对特定的轨道电路传输参数验证其能否满足调整、分流和机车信号工作状态的要求。

Domestic and overseas new technologies about conference system based on digital network in recent years are introduced, namely digital processing and transmission, high-frequency and infrared transmission, NOMA, mute corresponding interaction, camera shot auto tracking, video conference system, interactive digital board, multi-assembly-room system control, and audio-video and lighting network centralized control platform technology.

着重介绍近年国内外基于数字网络的会议系统新技术如数字处理和传输、高频和红外传输、NOMA、哑声对应互动、摄像自动跟踪、会议电视、交互数字白板以及多会议室系统控制和声像灯光网络化集控平台等技术，并举出典型的应用实例。

The design of the modern electronic device, except for must has multiple functions, but it also trend to achieve slightness, thinness, shortness and smallness in outer appearance. In order to seek such a trend, the components disposed in the electronic device must be reduced in volume correspondingly, and the connectors used therein also must be reduced in volume without exception. For example, the USB connector has developed a mini USB connector, and the digital video signal transmission interface evolves from a digital video interface to a high definition multi-media interface having a smaller volume and a faster transmission speed.

现代电子产品的设计除了要功能多样外，在外观上的趋势是追求轻、薄、短、小，为了追求这样的趋势，电子产品内的各个零件也必须跟着将体积缩小，其所使用的电连接器当然也不例外，如通用串行连接埠推出迷你版的通用串行连接端口，而数字影音讯号的传输接口也由数字视觉接口推演到体积较小，传输速度更快的高速高解析多媒体接口。

In digital signal transmission systems, parallel transmission is the most efficient transmission technique at present for non-ideal channel. In which, orthogonally multiplexed QAM system and discrete multitone system are two typical systems.

在数字信号传输系统中，并行传输是目前最有效的一种抗信道失真传输技术，而正交复用QAM和离散多载波是两种并行传输系统典型的实现方式。

And we also succeed in inosculating the technic of multithreading、 multiple buffers、 windows socket、 IP multicast and RTP real time transmission by using Visual C++6.0 and MS Directshow SDK, and obtained a good result. At the same time, we carried on researching the robustness of this software. We made the research findings of digital video transmission based on network used in applications of banks, and got very good social effects and economic benefit.

本文主要在以下方面做了深入的工作： 1、结合数字视频监控应用的需求分析，对研究网络视频传输技术的意义做了阐述和分析，并就如何充分利用现有网络资源和成熟的多媒体计算机技术进行视频监控等领域的具体应用做了有益的探索； 2、对&数字视频的网络传输&应用中所涉及到的关键技术进行了深入的分析、比较，并进行了有机的融合。

The numerousadvantages of SDH network ensure it outstands outof other digital TV transmissions, and plays an important role.

SDH 网络的众多优点，使它在数字电视的传输中脱颖而出，在数字电视的传输过程中担任重要的角色。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。