【 Weak current College 】 on basis of streaming media transmission---Power By 【 China power house network 】

Transmitted on the network, such as audio/video multimedia information at present mainly has the download and streaming two scenarios. A/V files are larger, so the need for storage capacity are large; at the same time, due to network bandwidth restrictions, downloads often take several minutes or even hours, so this kind of delaying treatment method. Streaming, voice, image or animation, and other time-based media from audio/video server to the user's computer for continuous, real-time shipping, users do not need to wait for all the entire file is downloaded, but only after a few seconds or 10 seconds of startup delay to watch. When the voice, and other time-based media player on the client, the rest of the file in the background from the server to continue to download. Streaming not only makes the start delay tenfold, dearly, and does not require too much of the cache. Streaming to avoid the user must wait for the entire file is downloaded from the Internet for all to see.

Streaming means the Internet/Intranet use streaming technology, continuous time-based media, such as: audio, video or multimedia files. Streaming media is played before and do not download the entire file, only the first part of the contents into memory, streaming media data stream at any time transfer at any time, just start with some delay. Streaming media implementation of key technology is streaming.

Streaming definition is very wide, now mainly refers to the network transmission media (such as video, audio) technology. Its specific meaning to the film and TV over the Internet to the PC. Implement streaming has two methods: real-time streaming (Realtimestreaming) and sequential streaming (progressivestreaming). In General, such as a video for the live broadcast, or use the streaming media server, or application such as RTSP protocol, that is, in real time for the live streaming. If the HTTP server, the file is sent via the order flow. Using the method of transmission depends on your needs. Of course, streaming files also support a full download before the player to your hard drive.

1. the order flow transmission

Order streaming is order download, download the file at the same time users can watch then line media, at a given moment, a user can only see the part that has been downloaded, but you cannot skip to yet download ahead, not like the sequential streaming real-time streaming during transport in accordance with the user connection speed be adjusted. As a standard HTTP server can send this form of files, or other special agreements, it is often referred to as HTTP streaming. Order streaming is more suitable for high-quality short fragments, such as titles, credits and advertisements, because the file is in the play before watching portion is lossless download, which guarantee the quality of the final movie playback. This means that users are watching, you must experience the delay, on a slow connection.

Publish via modem, short fragment looked very sequential streaming utility, it allows higher than the modem's data rate to create video clips. Despite the delay, after all, lets you publish a high-quality video clips.

Order the streaming file is placed in the standard HTTP or FTP server, easy to manage, basically the firewall or not. Order streaming is not suitable for long fragment and random access requirements of video, such as: lectures, speeches and presentations. It also does not support live broadcast, strictly speaking, it is an on-demand technology.

2. real-time streaming

Real-time streaming means that media signal bandwidth and network connections with rolls, so that the media can be viewed in real time. Real-time streaming and HTTP streaming, he needs a dedicated streaming server and Transfer Protocol.

Real-time streaming is always real-time transport, particularly suitable for on-site events, also supports random access, users can fast forward or rewind to view the contents of the front or rear. In theory, real-time stream is playing you can not stop, but in fact, possible cycle pause.

Real-time streaming must be equipped horse connection bandwidth, which means that in order to connect the modem speed, image quality is poor. Also, because of an error the missing information is ignored, network congestion or problems occur, the video quality is poor. If you wish to guarantee the video quality, sequential streaming maybe better. Real-time streaming requires a specific server, such as QuickTimeStreamingServer, RealServer and WindowsMediaServer. These server allows you to send to the media for more levels of control, system settings, manage more than a standard HTTP server. Real-time streaming also need special network protocols, such as: RTSP (RealtimeStreamingProtocol) or MMS (MicrosoftMediaServer). These protocols in a firewall may sometimes have problems, causes the user cannot see the contents of some sites in real time.