Unequal Error Protection Method For IPTV Transporort Stream

IPTV is a prospective multimedia service over IP network, but IPTV is still lack of QoS guarantee due to the"best effort"transmission manner of IP network, so research to the robust video transmission over IP network is meaningful and important to IPTV service. This paper mainly foucused on the error control algorithm over IP network.The background information and some related aspects of compressed video transmission over IP network was introduced in the first part of this paper.Then, aiming at the packet loss recovery, this paper proposed a new UEP algorithm. The main work covered the following two parts: first, based on LEP (Length of error propagation), this paper proposed a new metric ENCS (Expected number of corrupted slices) to distinguish the importance of video sequence, ENCS can distinguish the importance not only between different frames, but also between different packets. Then this paper proposed a new UEP algorithm UEPE, which had better simulation results under median and high redundancy than the exsited methods; second, this paper also improved the 2-state linear network estimation algorithm. The improved algorithm is more precise at times when the network condition changed sharply. Afterwords, aming at the undesirable performance of ENCS in the low redundancy situation, this paper proposed a new UEP algorithm UEPU and adpapted the FEC allocation algorithm, making it more reasonable under the low redundancy situation. Simulation results showed that the utility algorithm can further improve the video quality in low redundancy situation.Then, focusing on the multicast situation, this paper proposed a layered UEP algorithm. First, aiming at the bad network condition, this paper introduced a UEP algorithm of actively droping frames, whose main idea is to exchange source rate for channel rate, and improve the video quality under bad network situation. Second, layed UEP algorithm was proposed aiming at the multicast situation, which improved the video quality for end users who had bad network condition and had good faireness among diffrenet users.Then, this paper discussed the congestion control issue for non TCP flows, and introduced a new idea of congestion detection based on one-way-delay increasing trend.