Streaming media refers to the use of streaming technology in internet/intranet for continuous time-based media, such as audio, video or multimedia files. Streaming media does not download the entire file before playback, only the beginning of the content into memory, streaming media stream at any time to play, but at the beginning of some delay. The key technology of streaming media implementation is streaming. Transmission of audio/video and other multimedia information on the network, mainly download and streaming two programs. A/V file is generally large, so the storage capacity required is also large, and due to network bandwidth constraints, the download often takes a few minutes or even hours, so this method of processing delay is also very large. When streaming, sound, image or animation and other time-based media from the audio and video server to the user computer continuous, real-time transmission, users do not have to wait until the entire file download complete, and only after a few seconds or ten seconds of the start delay can be viewed. When the sound waits for the base media to play on the client, the remainder of the file continues to be downloaded from the server in the background. Streaming not only causes the start-up delay to be 10 times times shorter, but also does not require too much cache capacity. Streaming avoids the disadvantage of users having to wait for the entire file to be downloaded from the Internet to view. For streaming media on the Internet, the transmitted files must be made into a streaming media format file suitable for streaming media transmission. Because the size of the multimedia files stored in the format is very large, it can take a long time to transmit on the existing narrowband network, which will cause the transmission interruption if the network is busy. In addition, the usual format of streaming media can not be transmitted by streaming media transport protocol. Therefore, files that need to be streamed in a streaming format should be preprocessed, and the file compressed to generate a streaming media format file. Two points should be noted here: one is to choose the appropriate compression algorithm for compression, so that the resulting file size is small. The second is to add streaming information to the file. because the interent is in the package for asynchronous transmission, so the multimedia data in the transmission to be broken down into many packets, due to network transmission instability, the routing of each package is different, so the time order to reach the client may change, veryto the occurrence of packet loss. Therefore, it is necessary to use caching technology to correct the chaotic situation caused by the change of data arrival order, and to use the cache to correctly sort the arriving packets, so that the video audio data can play continuously and correctly .. The cache is stored in a certain period of time data, the data stored in the cache time is temporary, the data in the cache is dynamic, constantly updated. Streaming media continuously reads the data from the cache during playback, and the data is immediately erased when it is played, and the new data is stored in the cache .. Therefore, you do not need to consume too much cache space when you play streaming media files. Streaming media playback requires browser support。Typically, the browser uses MIME to identify a variety of simple file formats, all Web browsers are based on the HTTP protocol, and the HTTP protocol is built with mime。As a result, web browsers are able to mark numerous multimedia file formats on the Web, including various streaming media formats, via the built-in mime of the HTTP protocol ..
From for notes (Wiz)
2016 30th Wednesday-streaming media part concept
