Summary of common streaming media protocols and their application scenarios

Recently, I have been confused by the live streaming latency problem. For this reason, I have compiled some protocol information about common streaming media, hoping to help me solve the live streaming latency.

1. rtmp (real time messaging protocol)
Real-time message transmission protocol released by Adobe. Based on TCP, this protocol is a network protocol designed for real-time data communication. It is mainly used for audio and video communication between the Flash/air platform and the streaming media/interactive server that supports the rtmp protocol, the default port is 1935. Generally, FLV and f4v streams are transmitted.

2. RTSP/RTP/RTCP protocol family (Real-Time Streaming Protocol)
Real-time stream transmission protocol, developed by RealNetworks. The RTSP architecture is located on RTP (real-time transmission protocol) and RTCP (RTP Control Protocol). It uses TCP or UDP for data transmission. Compared with HTTP, the RTSP protocol family has the advantage of being able to control video frames, so it can carry applications with high real-time performance. The default port is 554. Generally, streams in ts and MP4 format are transmitted.

3. HLS (HTTP live streaming)
××× Streaming media protocol. M3u8 is used as the index file, and the video is a segment file in MPEG2-TS format. If it is a live video stream, update the m3u8 file to live the video. Because the final video is a fragment file, the length of the list video is delayed. Therefore, it can only be used for quasi-real-time video streams with less real-time requirements. The file storage format is TS + m3u8.

4. HDS (HTTP dynamic streaming)
The Streaming Media Protocol launched by Adobe is essentially similar to the HLS policy, that is, by indexing files + video clips. However, the index format and video clip format are obviously different. The file storage format is FLV/f4v/MP4 + f4m (similar to m3u8)

5. Smooth streaming
Microsoft also launched Microsoft smooth streaming, which is the MSS video broadcast method. The video format is segmented MP4. The file storage format is ismv + isml (similar to m3u8)

6. Http video Protocol
There is nothing special about the original HTTP video protocol, that is, the general progressive download of HTTP files. The essence is to download a video file. The feature of the video file itself is that there is a header information, and some video frame data, it can be completely decoded and played. Obviously, you need to put the header information of the video file in front of the file.

7. HTML5
At the same time, HTML developers are not lonely, and HTML5 is launched. In essence, this method is no different from the previous HTTP video protocol. However, the player does not rely on specific plug-ins such as flash or other playback software, but supports direct video playback in the browser. The video tag is embedded in HTML and the URL of the video is directly specified. However, different browsers support different audio and video formats.

# Behind-the-scenes highlights: When I consulted the R & D engineers of the old dongjia, the old brother said, "Our company is a leased line from the live broadcasting source, there is no latency. "We are monitoring the probe service we bought for live broadcasting." Haha ...... Okay. Sorry, I forgot ......

Summary of common streaming media protocols and their application scenarios