Unbalanced Quantized Multi-State Video Coding

Multi-State Video Coding (MSVC) is a multiple description scheme based on frame-wise splitting of the video sequence into two or more subsequences. Each subsequence is encoded separately to generate descriptions which can be decoded independently. Due to subsequence splitting the prediction gain decreases. but since reconstruction capabilities improves, error resilience of the system increases. Our focus is on Multi-State Video Coding with unbalanced quantized descriptions, which is particularly interesting for video streaming applications over heterogeneous networks where path diversity is used and transmission channels have varying transmission characteristics. The total bitrate is kept constant while the subsequences are quantized with different step sizes depending on the sequence as well as on the transmission conditions. Our goal is to figure out under which transmission conditions unbalanced bitstreams lead to good system performance in terms of the average reconstructed PSNR. Besides, we investigate the effects of intra-coding on the error resilience of the system and show that the sequence characteristics, and in particular the degree of motion in the sequence, have an important impact on the decoding performance. Finally, we propose a distortion model that is the core of an optimized rate allocation strategy, which is dependent on the network characteristics and status as well as on the video sequence characteristics

Scalable Multiple Description Coding and Distributed Video Streaming over 3G Mobile Networks

In this thesis, a novel Scalable Multiple Description Coding (SMDC) framework is proposed. To address the bandwidth fluctuation, packet loss and heterogeneity problems in the wireless networks and further enhance the error resilience tools in Moving Pictures Experts Group 4 (MPEG-4), the joint design of layered coding (LC) and multiple description coding (MDC) is explored. It leverages a proposed distributed multimedia delivery mobile network (D-MDMN) to provide path diversity to combat streaming video outage due to handoff in Universal Mobile Telecommunications System (UMTS). The corresponding intra-RAN (Radio Access Network) handoff and inter-RAN handoff procedures in D-MDMN are studied in details, which employ the principle of video stream re-establishing to replace the principle of data forwarding in UMTS. Furthermore, a new IP (Internet Protocol) Differentiated Services (DiffServ) video marking algorithm is proposed to support the unequal error protection (UEP) of LC components of SMDC. Performance evaluation is carried through simulation using OPNET Modeler 9. 0. Simulation results show that the proposed handoff procedures in D-MDMN have better performance in terms of handoff latency, end-to-end delay and handoff scalability than that in UMTS. Performance evaluation of our proposed IP DiffServ video marking algorithm is also undertaken, which shows that it is more suitable for video streaming in IP mobile networks compared with the previously proposed DiffServ video marking algorithm (DVMA)

Uma abordagem para o transporte de vídeo digital baseada em técnicas proativas de QoS

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Tecnológico. Programa de Pós-Graduação em Engenharia Elétric