More Adaptive Ts Flow Based On Darwin Technology Push The Research And Implementation Of Server

In recent years, along with the positive development of our country’s information construction,and the steady progress of tri-networks integration,digital conversion work of the cable TV in the radio and television industry is is in an orderly manner and is speeding up the pace. By the end of May2011, the cable digital TV users in China are already up to97million persons. However, the vast majority of services that users can enjoy are based on one-way network, and have a lack of interaction. Thus, operators need to accelerate the development of two-way network and provide users with a variety of high-quality interactive services, and VOD is one of the current hot interactive businesses.Video server is an important part of the VOD system, and its development costs are high, moreover,the overall solution based on EPOAM technology must have the function to send TS stream. In order to reduce the input costs of the VOD system, the first thing we should consider how to develop a high quality of video server with low cost.In consideration of the above, we choose the Darwin Streaming Server, which is Apple’s open source project, and will expand its function, and then it will have the ability to send MPEG-2TS stream and H.264TS.First, we need to do is to analyze the structure and source code of the DSS to figure out how to add the module,which has the ability to send MPEG-2TS stream, into the DSS. Considering RTP/RTCP protocol which the DSS supports will increase the working pressure of Set-top box cpu, we decided to use the UDP protocol to send TS stream.But the UDP protocol itself has no flow control mechanism, through the analysis of the structure of TS bag, we make the PCR as a key parameters and send TS stream with its own ideal bit rate,and finally we realizes the flow control.Finally, we make the DSS has the ability to send MPEG-2TS stream and H.264TS stream, and then we tested a series of different TS files, the screen is clear and smooth, without mosaic phenomenon.Because we strictly send TS stream with its own ideal bit rate, the average error is below five milliseconds,the maximum errors are less than10 milliseconds, the time error is always maintained at the millisecond level and will not increase over time.Because this streaming server is fully consistent with ISMA standard, it is also suitable for all other IP-based network environment, and can be used as Video server of both BPQAM VOD and Ethernet VOD, at the same time, the terminal equipment can be DVB STB,IP STB or PC.Obviously, the streaming server has become Multi-adaptiv.