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UDDP: A user datagram dispatcher protocol for wireless multimedia sensor networks
, Article 2012 IEEE Consumer Communications and Networking Conference, CCNC'2012 ; 2012 , Pages 765-770 ; 9781457720710 (ISBN) ; Khansari, M ; Rabiee, H. R ; Salehi, M ; Sharif University of Technology
2012
Abstract
The quality of service inWireless Multimedia Sensor Networks (WMSN) is related to packet loss rate. Recently different studies have been done on developing efficient protocols in the transport layer for controlling packet loss in WMSN. However, all of these protocols are independent of the characteristics of multimedia content. In this paper, a novel transport layer protocol, called User Datagram Dispatcher Protocol (UDDP), is proposed to minimize the packet loss ratio in WMSN by considering traffic characteristics, the inter-arrival pattern of packets and packet priority. UDDP is a new cross-layer transport layer that uses information of MAC and application layers to distribute packet...
A high video quality Multiple Description Coding scheme for lossy channels
, Article Proceedings - IEEE International Conference on Multimedia and Expo, 11 July 2011 through 15 July 2011, Barcelona ; 2011 ; 19457871 (ISSN) ; 9781612843490 (ISBN) ; Sadeghi, K ; Shirmohammadi, S ; Sharif University of Technology
2011
Abstract
Multiple Description Coding (MDC) is a technique where multiple streams from a source are generated, each individually decodable and mutually refinable. In this paper, a new Mixed Layer MDC (MLMDC) scheme is presented which achieves a higher side quality compared to conventional MDCs. The improved side performance leads to higher average video quality at the receiver in lossy networks. For each DCT coefficient, we generate two coefficients: Base Coefficient (BC) and Enhancement Coefficient (EC) which are combined together. When all descriptions are available, they are decomposed and decoded to achieve high quality video. When one description is not available, we use estimation to extract as...
Multiple Description Video Coding Based on Base and Enhancement Layers of SVC and Channel Adaptive Optimization
, Ph.D. Dissertation Sharif University of Technology ; Haj Sadghi, Khosrow (Supervisor) ; Shirmohammadi, Shervin (Supervisor)
Abstract
Multiple distortion coding is a promising solution for video transmission over lossy channels. In MDC multiple descriptions of a source are generated which are independently decodable and mutually refinable. When all descriptions are available, the corresponding quality is called central quality; otherwise it is called side quality. Generally, there exist a trade-off between side and central quality in all MDC schemes. The MDC methods which provide better central-side quality trade-off are of more interest to the designers.In this thesis a new MDC scheme is introduced which has better trade-off between side and central quality. In other words, for the same central quality, it provides higher...
A mixed layer multiple description video coding scheme
, Article IEEE Transactions on Circuits and Systems for Video Technology ; Volume 22, Issue 2 , February , 2012 , Pages 202-215 ; 10518215 (ISSN) ; Sadeghi, K. H ; Shirmohammadi, S ; Sharif University of Technology
Abstract
Multiple description coding (MDC) is a technique where multiple streams from a source video are generated, each individually decodable and mutually refinable. MDC is a promising solution to overcome packet loss in video transmission over noisy channels, particularly for real-time applications in which retransmission of lost information is not practical. A problem with conventional MDC is that the achieved side distortion quality is considerably lower than single description coding (SDC) quality except at high redundancies which in turn leads to central quality degradation. In this paper, a new mixed layer MDC scheme is presented with no degradation in central quality, and providing better...
Error concealment using wide motion vector space for H.264/AVC
, Article 2011 19th Iranian Conference on Electrical Engineering, ICEE 2011, 17 May 2011 through 19 May 2011 ; May , 2011 ; 9789644634284 (ISBN) ; Panahi, M. A ; Kasaei, S ; Sharif University of Technology
2011
Abstract
Due to fast growth of wireless mobile networks, video transmission over wireless media has been widely studied. As wireless networks are error prone, there is a high possibility of loss in sent packets. Since time limitations in real-time video applications should be met, the delay-related to resending packets is not acceptable and the error should to be concealed at receiver side. With respect to different concealment methods, two new methods for temporal error concealment are proposed. In the first method, an optimized set of motion vectors is formed using motion vectors in surrounding blocks of the lost macroblock, and then this set is searched for the best motion vector. For extending...
Rate/distortion optimization in multiple description video coding
, Article Signal Processing: Image Communication ; Volume 36 , August , 2015 , Pages 95-105 ; 09235965 (ISSN) ; Haj Sadeghi, K ; Shirmohammadi, S ; Moallem, P ; Sharif University of Technology
Elsevier
2015
Abstract
Abstract Multiple Description Coding (MDC) is a technique where multiple streams from a video source are generated, each individually decodable and mutually refinable. MDC is a promising solution to overcome packet loss in video transmission over noisy channels, particularly for real-time applications in which retransmission of lost information is not practical. The error resiliency feature of MDC is achieved at the cost of redundancy, and the required amount of redundancy for each frame depends on the packet loss ratio and also the importance of the frame in the sequence. Due to the error propagation in video transmission over lossy channels, reference frames of a Group of Pictures (GOP)...
Network-adaptive multipath video delivery over wireless multimedia sensor networks based on packet and path priority scheduling
, Article Proceedings - 2010 International Conference on Broadband, Wireless Computing Communication and Applications, BWCCA 2010, 4 November 2010 through 6 November 2010 ; 2010 , Pages 351-356 ; 9780769542362 (ISBN) ; Akbari, B ; Sharif University of Technology
Abstract
In this paper we investigate multi-path transmission of video over Wireless Multimedia Sensor Networks (WMSNs). Our objective is to provide a transmission mechanism to improve the video quality perceived at the receiver while considering energy, bandwidth and delay constraints of the network. Our approach is based on packet and path priority scheduling in multipath video transmission over WMSN. Video packets are classified according to their types and more important packets are transmitted through paths with better conditions. Path conditions are evaluated by a score mechanism using variant parameters such as free buffer size, energy, hop count and packet loss. Since path conditions are...
A joint source-channel rate-distortion optimization algorithm for H.264 codec in wireless networks
, Article 13th International Computer Society of Iran Computer Conference on Advances in Computer Science and Engineering, CSICC 2008, Kish Island, 9 March 2008 through 11 March 2008 ; Volume 6 CCIS , 2008 , Pages 946-950 ; 18650929 (ISSN); 3540899847 (ISBN); 9783540899846 (ISBN) ; Rabiee, H. R ; Ghanbari, M ; Sharif University of Technology
2008
Abstract
In recent years, the demand for video transmission over wireless communication networks is growing very fast. The H.264 video compression standard which offers high quality at low bit rates, is a suitable codec for applications that require efficient video transmission over wireless networks. While the compressed videos are transmitted through error-prone networks, error robustness becomes an important issue. In this paper, a joint source-channel Lagrange optimization method in which the distortion of the decoder is estimated without using feedback which can be used for both multicast and point-to-point applications is proposed. The experimental results show that the new algorithm has a good...