多媒体音频制作与处理技术

音频是多媒体应用软件的重要组成部分，它具有增强多媒体信息呈现效果的作用。有时，一段音乐或效果声，远胜似一大段文本的含义。音乐给人的想象和思维空间非常丰富，因此深受多媒体制作人员的喜爱。一个好的多媒体应用软件，在音频制作与处理方面总是很讲究的。１建立音...     

用好Adobe Premiere中的音频处理工具

Premiere 6.0是Adobe公司在2001年推出的产品．它是该公司基于QuickTime系统推出的一个多媒体影音制作软件．与其4．0、4.2、5.0、5．1和5．5等版本相比．Premiere 6．0在所支持的素材格式、编辑、音频效果、过渡特技等方面的功能都有相当大的扩展：尤其是在音频方面，能够支持MP3格式．使音乐素材更加容易获得．音频效果功能上都作了较大地改进。     

多媒体通信中的音频处理技术

当今社会已进入了信息化新时代，一个多学科交叉、跨行业的、新兴的多媒体信息技术已经形成。现代通信正朝着多维空间、多种媒体组合的通信方向迈进，因而各种信息处理技术显得尤为重要。     

传输通道中的音频处理技术

随着计算机技术、数字压缩技术以及网络技术的不断成熟和发展，数字化已走进各级电视台。数字特技、虚拟演播室、网络硬盘阵列等用于节目制作播出的网络设备日渐成熟，不少电视台已经完成了全硬盘播出系统网络化的建设，取消了磁带播出。实现制作、编审、播出网络一体化、数字化，为即将实施的全数字信号传输打下了坚实基础。特别是随着电视频道的增多，电视节目日益丰富，画面质量也越来越清晰。-我台自办三套节目，全部采用全硬盘播出。节目来源不同，有转播中央卫星信号、内蒙台信号，有光盘采集的节目素材、也有移动盘复制的节目、还有磁带交流的蒙语节目、再加上自己制作的新闻专题等，繁纷众多的节目丰富了荧屏，但也产生了一个新的问题。一方面，画面质量确实提高了；另一方面，使得节目源声音大小很难统一，再加上后期制作的设备档次不一，不同设备对音频电平大小的衡量标准不一样，导致声音方面存在着一些问题。即众多的频道之间、不同节目之间声音的大小还存在差别。观众更换频道，或欣赏不同节目时必须重新调整音量，否则声音忽大忽小，这个问题如不解决，就不能说是播出质量提高了。     

数字电视的音频制作流程

本介绍了DTV节目平台的数字音频在网络状态下采集、存储、加工及播出的基本流程，并把数字音频工作站作为节目平台音频处理的核心技术进行了重点说明。     

多媒体系统的音频技术

本文讨论了ＣＤ－ＲＯＭ多媒体计算机、静态图象多媒体计算机和实时动态图象多媒体计算机等多媒体系统的音频技术，它包括对外部节目源的录制与重放，ＣＤ唱片的重放和利用ＭＩＤＩ作曲并实现音乐合成。     

音频的数字化处理技术探究

随着计算机网络技术的发展,音频的数字化处理技术的应用越来越广泛。本文阐述了音频信号的定义,并从音频信号的采集、量化、编码、压缩、噪声处理、提取、抗混迭滤波等方面对音频信号的数字化处理进行了阐述。通过本文的分析论述对音频数字化技术有了全面的认识,为其应用奠定了理论基础。     

Audio visual interaction in multimedia

Audio-visual interaction is a very important issue in personal communication applications. The research and development of multimedia communication systems should account for this interaction. In this paper, we address a number of areas related to audio-visual interaction, such as automatic lipreading, speech-driven talking heads, and lip synchronization. In particular, we will discuss a new trend in video coding research: joint audio-video coding. Given that mouth movements are very difficult to code because of its rapid, complex, and non-rigid motion (so conventional block-based motion-compensation methods fail), we will explain how having extra help from the acoustic signal can enable us to code the mouth movements more efficiently     

音频信号分析仪

以单片机和FPGA为核心的音频信号分析仪,利用傅里叶变换FFT法分析音频信号频谱.该分析仪主要由信号前级调理、有效值检波、采样保持等功能模块组成.频谱测量频率范围为20 Hz～10 kHz,频率分辨率达到5 Hz,幅度范围(峰-峰值)为10 μV～20V.系统设计控制简单,设计成本低,具有很高的实用价值.     

音频信号分析仪

以单片机和FPGA为核心的音频信号分析仪,利用傅里叶变换FFT法分析音频信号频谱。该分析仪主要由信号前级调理、有效值检波、采样保持等功能模块组成。频谱测量频率范围为20H加10kHz,频率分辨率达到5Hz。幅度范围（峰-峰值）为10μV-20V。系统设计控制简单,设计成本低,具有很高的实用价值。     

Authoring and execution environments for multimedia and robotic performances

Recent advances in multimedia systems and robotics encourage the development of novel media forms that combine the use of multimedia objects with robotic actors. We present an authoring system for planning robotic actor behavior and linking this behavior with multimedia object rendering.     

视频、音频信号处理器-多媒体DSP

简要介绍了多媒体技术及多媒体DSP,分析了多媒体DSP的内部结构包括运算单元,寄存器组,高速缓存等;外部接口包括音频、视频、各种通用总线接口;总线控制技术及其内存管理。给出了多媒体DSP的高速运算特性。最后以Philips公司的TriMediaTM芯片PNX1301为核心设计了H263／MPEG4编解码器。     

Audio interfaces and signal processing

This paper deals with problems raised by speech and sound pick-up, processing and reproduction in telecommunication systems. Those problems which occur as soon as sound and speech are involved in a communication are briefly explained in the introduction. Then the noise and acoustic echo cancellation problems are discussed and current techniques are presented. The remaining part of the paper is dedicated to sound reproduction techniques which aim at preserving the spatial characteristics of sound and which take into account the characteristics of spatial hearing. Finally, some data about standardization are recalled and future applications are sketched.     

Signal processing for networked multimedia

Real-time transmission of multimedia data over packet networks poses several interesting problems for signal processing research. Although the range of these problems covers a large variety of topics, currently two groups appear to attract the most attention. The first group concerns adapting the signal compression techniques to address the special requirements imposed by the packet networks, including accommodating for packet losses, delays, and jitter; providing capability for multipoint; and coping with the heterogeneous nature of today's networks. The second group of problems is related to protecting the intellectual property rights associated with the transmitted multimedia data. The increasing availability of high-bandwidth networking makes it extremely easy to illegally duplicate and disseminate digital information. Unless a mechanism can be established to protect the rights of the content providers, commercial use of networked multimedia will remain extremely limited     

Distributed multimedia information handling and processing

Requirements for distributed processing of multimedia information are summarized and compared with the latest efforts in standardization. An approach to a communication model that can be viewed as a special form of a model for open distributed applications is outlined. The functions of a system for the handling of multimedia information and a functional model approach, including a supporting environment, are considered. Synchronization aspects of isochronous and anisochronous communication are also outlined. The model is still under development. Detailed work needs to be done in the areas of formal specification of abstract services and modeling of communication protocols     

一种适合多媒体处理的新型芯片

介绍ＭＭＸ技术的基本内容及带有ＭＭＸ技术的微处理器，以ＭＭＸ技术在视频会议系统上的应用为例，侧重分析ＭＭＸ技术给多媒体与通信应用带来的性能改善，并对ＭＭＸ技术的应用及发展前景进行探讨。     

Satellite onboard processing for multimedia applications

For future multimedia applications, satellites might play an important role. For broadcast applications satellites are ideally suited to illuminate a large geographical area. However, multimedia applications are interactive, and are therefore a combination of a broadcast mission and a multipoint-to-point mission. The natural question is, can a satellite system compete with the capacity provided by terrestrial cable networks? If the answer is positive, and it shown in this article that it is, a second question arises: what new developments are required to migrate from the state-of-the art satellite technology to such advanced concepts? Taking the example of the European Space Agency's activities in this field, an overview of the required building blocks which make up a complete multimedia communication satellite system are described. Based on this technological overview a discussion of the systems developed by European space industries with support from the European Space Agency is given