Design And Implementation Of Digital Film Transfer System Based On UDP Protocol

As the film industry and the Internet technology evolves,the fact that the traditional transport method of digital film copy is limited and inflexible brings another object of study.Some companies and organizations have begun to provide and support the end-to-end transport service of digital file by combining the Internet technology.In this paper,we propose a reliable UDP-based digital file transport system.By setting different applicable scenarios with commercial film chain,government and education agency,the proposed adaptive transport schedule realizes the distribution of digital programs and movies effectively.Aiming at the characteristics of UDP,a utilization of the adaptive transport schedule by controlling the amount of both total sending rate and the FEC code ratio is studied.The main results are as follows:(1)Based on Reed-Solomon Codes and interleaving matrix,a packet-level error resilience scheme is proposed for the characteristics of connectionless and non-guaranteed transport.In terms of generator matrix,the performance of the codec matrix is improved based on the van der Mammon matrix and the conventional Cauchy matrix.(2)According with the current business requirement,the UDP message format is redesigned and matched with combining strategies of out-of-order reconstruction and selective repeat request.In addition to the error resilience,the transmission system enables the reliability and orderliness of message by using these two mechanisms.(3)Researching on the shortcomings of UDP in congestion control mechanism,a prediction model based on Long Short Term Memory Network is trained.Moreover,an adaptive congestion control scheme based on this prediction model is put forward.The scheme mainly utilizes the memory capability of neural network LSTM to estimate the sequential state of temporal data in the next time period.Simulation experiments show that the LSTM-based adjustment strategy can effectively control the delay fluctuation,and improve performance in throughput and utilization efficiency.(4)Based on the environment of the digital film distribution system and the experimental network,the feasibility and potentiality of the system are verified.