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This paper introduces a scalable coding method for video broadcast in error-prone wireless environments, combining Multiple Description Coding (MDC) and Subband Extension of H.264/AVC to optimize bandwidth utilization and enhance error resilience.
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Low Redundancy Layered Multiple Description Scalable Coding Using The Subband Extension Of H.264/AVC Department of Electrical and Computer Engineering The University of British Columbia Written by Hassan Mansour, Panos Nasiopoulos, Victor Leung Jung-Hwan jhlee@os.korea.ac.kr 07.04.25 Operating System Lab
Outline • Abstract • Introduction • Subband Extention OfH.264/AVC • Multiple Description Scalable Coding • Proposed Layered Multiple Description Scalable Coding • Experimental Results • Conclusion
Abstract • The task of broadcasting video in wireless environments • Requires codingefficiency and error resilience techniques. and bandwidth utilization • The one hand, error resilience and recovery from packet delay or loss. • Layered Multiple Description Scalable Coding (LMDSC) • Video broadcast over wireless networks • Subband extension of H.264 • Multiple Description Coding (MDC) • Eliminating redundancy between the video streams
Introduction • Video transmission over wireless networks • Problem • The highly error-prone nature of wireless environments • The unexpected variations in available bandwidth • Solution • The demand for bandwidth adaptive codec. • Robust error resilience techniques. • Multiple Description Coding (MDC) • Path or server diversity can reduce the effects of packet delay and loss • It suffers from data redundancy and thus requires additional bandwidth.
Subband Extention OfH.264/AVC • Frames A and B from the original video sequence, a High Pass (HP) frame is produced after the prediction step and a Low Pass (LP) frame is produced after the update step. • Each set has half the temporal resolution as that of the original stream.
Subband Extention OfH.264/AVC • The packets contain HP information, then the decoder can be modified to recover from packet loss by inserting a zero residual frame instead of the lost frame. • A LP packet is dropped, then the consequence is more severe since that can greatly affect the PSNR and quality of the decoded stream.
Multiple Description Scalable Coding • Multiple Description Coding (MDC) • First Launched Error resilience technique for the reliable transmission of video over the wireless networks. • Complementary video streams are transmitted from one or several server locations along different paths to the client. • Second step in the evolution of this technology by merging scalable coding • Scalable coding facilitated the adaptability of the different video descriptions to variations in channel bandwidth
Proposed Layered Multiple Description Scalable Coding Channel-bandwidth adaptive since the HP packets have a priority measure. LP and lower layer packets have a higher priority than higher layer packets such that in the case of network congestion or a sudden reduction in channel bandwidth, higher layer (lower priority) HP packets are dropped to ensure the correct reception of higher priority packets.
Conclusion • Layered Multiple Description Scalable Coding (LMDSC) • Offer clients with non-homogeneous bandwidthcapabilities,video data that can adapt to channel bandwidthfluctuations and error recovery at very low bit-rates. • LMDSC significantly surpasses the decodedWhenfaced with the same number packet losses. • LMDSC to support variable channelbandwidth • error resilience • non-homogeneous bandwidthcapabilities