H.264 based MDC

H.264/AVC-Based Multiple Description Coding For Wireless Video Transmission Refat Kibria Dept. of Informatio n and Communicatio n Eng. Inha University 253 Yonghyun-dong, Nam-gu [email protected] Joohee Kim Dept. of Information and Communicatio n Eng. Inha University 253 Yonghyun-dong, Nam-gu Incheon,402-751, South Korea [email protected] Abstract: Multiple description coding is a promising solution for robust video communication over non-prioritized and unpredictable netwo rks . In this paper , we propose a new multiple description coding scheme for the H.264/AVC video coding standard which enables adaptive and robust video transmission in wireless networks. In the proposed MDC, each description has a different prediction loop and contains additional motion information for the frame s included in the other description. This addition al motion informati on is used to enhance the recons tructe d video qualit y when only one of the two descrip tions is receive d. Simula tion results show that the proposed MDC has a low redundancy and outperforms single description coding (SDC) for video transmission over unpredictable and error-prone networks. Key–Words: Multiple description coding, H.264/AVC, video coding, wireless video 1 Introducti on With the development of mobile communication tech- nologies, it is expected that there will be increasing demand for video streaming services over wireless ad hoc networks. Possibl e application s of video streaming over ad-hoc networks include video conferenc- ing, highway automation, broadband wireless Inter- net access, and search-and-rescue missions. However, video transmission over wireless ad-hoc networks has man y tec hnic al cha lle nges . Since ad- hoc networks are deployed instantly in situations where infrastruc- ture is unavailable, the network topology is frequently changing due to node mobility and links are contin- uously establi shed and broken. Therefore, the avail- ability and quality of a link fluctuates and transmission error is mor e frequent than that in single-hop wireless networks. Multiple description coding (MDC) has emerged as a pr omi si ng techni que to enhance the error resilience of a video transport system and extensive re- search on MDC has been performed recently [2, 3, 4, 5, 6, 7, 8]. An MD coder generates two or more inde- pendently decodable and equally important descrip- tions (or bitstreams) so that each description alone provides low but acceptable quality and multiple de- scr ipti ons lead to higher qua lit y . Thi s MD codi ng approach is especially effective for delay-constrained video transmission in wireless ad-hoc networks where the er ror rate is hi gh and the networ k conditions change frequently due to potential node mobility. The benefits of using MDC in video streaming can be fur- ther amplified when MDC is combined with multi- pat h tra nspo rt [3, 9]. In these appro aches, each description is explicitly transmitted over an independent pat h to a rec ei ver . MDC combi ned with multi- pat h transport can achieve higher throughput and increase tolerance to packet loss and delay due to network con- gestion because the probability of having all the paths simulta neously congest ed is low . In wireless ad-hoc networks, multiple paths can be supported by prac- tical multi-path routing protocols such as DSR and TORA [10]. The H.264/AVC video coding standard [1] pro- vi des a hi gh cod ing ef fic ienc y and has a hi gh de- gree of flexibility for operation in a variety of networ k cond iti ons bec ause man y res tri cti ons concer ning the data structure (e.g., picture ordering, slice structure, and macrob lock order ing) are remo ved. Since the H.264/AVC video coding standard provides a high coding efficiency, it is a good choice for video com- pressi on in wireless networks. Recent ly , sev eral MD coding methods for H.264/AVC that increase the error resilience of the video transmission system and

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H.264 based MDC