Streaming media流媒体英语作文
好学英文网解释:Streaming media:数据流媒体,即流媒体;采用流式传输的方式在因特网与内联网播放的媒体格式。
所谓流媒体是指采用流式传输的方式在Internet播放的媒体格式。流媒体又叫流式媒体,它是指商家用一个视频传送服务器把节目当成数据包发出,传送到网络上。用户通过解压设备对这些数据进行解压后,节目就会像发送前那样显示出来。在这里好学英文网希望大家对流媒体有一个较为系统的认识,以便更好地去阅读以下这篇“Streaming media”范文。
请参考范文:
Streaming media
Many existing radio and television broadcasters provide Internet "feeds" of their live audio and video streams (for example, the BBC). They may also allow time-shift viewing or listening such as Preview, Classic Clips and Listen Again features. These providers have been joined by a range of pure Internet "broadcasters" who never had on-air licenses. This means that an Internet-connected device, such as a computer or something more specific, can be used to access on-line media in much the same way as was previously possible only with a television or radio receiver. The range of material is much wider, from pornography to highly specialized, technical webcasts. Podcasting is a variation on this theme, where—usually audio—material is downloaded and played back on a computer or shifted to a portable media player to be listened to on the move. These techniques using simple equipment allow anybody, with little censorship or licensing control, to broadcast audio-visual material on a worldwide basis.
Webcams can be seen as an even lower-budget extension of this phenomenon. While some webcams can give full-frame-rate video, the picture is usually either small or updates slowly. Internet users can watch animals around an African waterhole, ships in the Panama Canal, traffic at a local roundabout or monitor their own premises, live and in real time. Video chat rooms and video conferencing are also popular with many uses being found for personal webcams, with and without two-way sound.
YouTube was founded on 15 February 2005 and is now the leading website for free streaming video with a vast number of users. It uses a flash-based web player to stream and show video files. Registered users may upload an unlimited amount of video and build their own personal profile. YouTube claims that its users watch hundreds of millions, and upload hundreds of thousands, of videos daily.
流媒体发展前景十分广泛,几乎涉及到我们日常观看视频的99%以上;作文-地带在这里同时希望大家了解一下流媒体格式及传输协议。
常用流媒体格式
声音流、视频流、文本流、图像流、动画流
RA:实时声音
RM:实时视频或音频的实时媒体
RT:实时文本
RP:实时图像
SMIL:同步的多重数据类型综合设计文件
SWF:micromedia的real flash 和shockwave flash动画文件
RPM:HTML文件的插件
RAM:流媒体的元文件,是包含RA、RM、SMIL文件地址(URL地址)的文本文件
CSF:一种类似媒体容器的文件格式,可以将非常多的媒体格式包含在其中,而不仅仅限于音、视频。
流媒体产业
1、realnetwork公司拥有流媒体播放格式有三种;
2、apple公司:quicktime\mov;
3、microsoft公司;
(1)asf\wmv\wma
(2)avi
(3)mpeg\mpg\dat
4、micromedia公司
(1)flash的swf格式
(2)metastream的mts格式
(3)aam多媒体教学课件格式,可将authorware生成的文件压缩为aam和aas流式文件播放
流媒体的传输协议
1、RSVP:资源预留协议
2、RTP:实时传输协议
3、RTCP:实时传输控制协议
4、MMS:微软流媒体服务协议
5、RTSP:实时流协议
6、MIME:多目因特网电子邮件扩展协议