Design And Optimization Of Low Delay Full HD Wireless Video Transmission System

In recent years,with the development of Internet of Things technology and multi-media transmission technology,more and more intelligent devices have not only been limited to the superposition of traditional functions but also added a variety of audio and video interaction means to interact with users.In order to be portable and mobile,innovative Internet of things devices often use Wi-Fi technology to communicate in a mobile network environment.Compared with the wired network,Wi-Fi technology has a higher bit error rate,more interference,and longer transmission delay.Therefore,how to transmit video with low delay,bit error rate,and strong anti-interference ability has become the goal of many major companies and scientific research workers worldwide.In order to reduce the time delay of multi-media transmission in the mobile local area network,this thesis proposes a wireless video transmission strategy based on a hybrid forward error correction algorithm and designs the signaling layer and video transmission layer of this strategy,which can attain high-quality video transmission with lower delay in a wireless transmission environment.Based on this strategy,a cross-platform real-time video transmission system has been developed.This thesis has designed the system’s hardware construction,software programming,and algorithm implementation.Based on this system,this thesis has tested the proposed video transmission strategy through various Qo E indicators such as transmission delay,transmission bandwidth,and the success rate of forward error correction decoding.Finally,this thesis verifies the low delay improvement effect of the hybrid forward error correction video transmission strategy.The main research work and achievements of this thesis are as follows:(1)This thesis proposes a novel video transmission strategy that can establish a low-delay video transmission process in the system,to improve the end-to-end delay of the overall system.This strategy uses FEC technology to reduce the transmission delay in 1080 p and other large-resolution video streams.At the same time,this strategy adopts negative retransmission technology and acknowledgment feedback technology to improve the robustness of the transfer process.It improves the smoothness of video playback in the random-packet-loss environment.(2)This thesis applies a packet loss prediction algorithm based on the Hidden Markov model in the above video transmission strategy.It divides the virtual network environment by different network packet loss rate states.Through this algorithm,the strategy can detect the current channel situation in real-time and make an accurate prediction of the channel packet loss rate the next time to make that the video transmission strategy can be dynamically changed.The packet loss rate state prediction accuracy can reach 90% by the test.(3)In this thesis,a cross-platform WLAN streaming media transmission system has been developed based on Raspberry PI-CM4 and an Android mobile APP.Zero-copy,multi-threading,and other related technologies optimize the dual-terminal data transmission program.This system also has a professional experimental operation interface.In a natural Wi-Fi environment,this thesis has tested the system to analyze the actual performance of the video transmission strategy.The results show that the strategy’s performance is greatly improved compared to the traditional protocols system.