Research On The H.264-Based Security Compression Algorithm For Streaming Media

By the updating and development of the streaming media technology, its security is taking into account. In the view of its universality , conveniency and vast data streaming in storage and transfer, how to design a stable encryption and arithmetic with high efficiency , high speed is an emergent problem that needs to be solved.In this thesis, we designed a project with an adjustable encryption level which based on the predictive coding mode. The proposed project used two key procedure -predictive mode in intra-frame coding and moving vector in inter-frame coding as encryption objects.The encryption degrees and safeness of the three levers increased stepwisely.The encryption and compression in the proposed project were executed synchronously which not only save much computation costs but also speed up the encryption. The project is real-time and manipulable.It is not complex and easy to reversible.The decipherment in the legal receiving end is simple and easy ,it won't need add extra consumption and easy to accomplish.The proposed project can be applied to wireless terminal that would have good application prospect.First, we researched the code of H.264 and analysised the key feature of algorithm. In the first section we lay a good foundation for the encryption adding into the compress process.Then we classified and compared all the video encryption proposed in the recent ten years. According to the different types of the algorithm ,we analyzed the safeness, realtime achievement, increasing of the data volume, data format compatibility, data operability, application range and so on. We also summarized the trend of the video encryption development.Finally, based the above foundation, we desighed a project with an adjustable encryption level that based on H.264 media streaming. There are 3 Jevels which distinguishingly apply in the online video request, long distance education, video supervisory, video chat, video meeting and so on.The experiment shows that the three levels don't multiply the extra byte and it is also easy to accomplish.