Presentation on theme: "Jung-Hwan Low Redundancy Layered Multiple Description Scalable Coding Using The Subband Extension Of H.264/AVC Department of Electrical."— Presentation transcript:
Jung-Hwan 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 Operating System Lab
Abstract The task of broadcasting video in wireless environments Requires coding efficiency 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 Of H.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 Of H.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 bandwidth capabilities, video d ata that can adapt to channel bandwidth fluctuations and error recov ery at very low bit-rates. LMDSC significantly surpasses the decoded When faced with the sam e number packet losses. LMDSC to support variable channel bandwidth error resilience non-homogeneous bandwidth capabilities