Analysis and Implementation of Raptor Codes for Video Multicast

2013 ◽  
Vol 347-350 ◽  
pp. 3845-3849
Author(s):  
Geng Wei ◽  
Cong Juan Li ◽  
Yu Dong Zhang

Packet loss is unavoidable in IP multicast using the UDP protocol that will serious influence video quality. In this paper we use the Raptor codes for video multicast to improve the video quality. Firstly, the principle of Raptor codes is analyzed in detail. Then the Raptor codes is implemented and transplanted in the video transmission system. Simulation results show that the video transmission system with Raptor FEC works which can overcome the packet loss effectively and improve the playback quality significantly.

2012 ◽  
Vol 195-196 ◽  
pp. 1106-1110
Author(s):  
Fu Xiao ◽  
Ting Hu ◽  
Jian Ping Yu ◽  
Ru Chuan Wang

TFRC protocol is very suitable for video transmission, while quality assessment is also essential in video transmission system. In this paper a real-time video transmission system based on TFRC protocol is proposed, and an evaluation model about the system is improved in the framework of Evalid. It assesses the quality and efficiency of the video transmission according to the actual video file, and analyzes losses frame in different video types during transmission as well as the picture quality in receiver. The results of simulation experiment in NS-2 show that when real-time video transmitted in complex network environment using this system, the receiver can get satisfactory video quality by reason of the TFRC protocol friendliness and the smoothness of sending rate.


2021 ◽  
Vol 11 (8) ◽  
pp. 3623
Author(s):  
Omar Said ◽  
Amr Tolba

Employment of the Internet of Things (IoT) technology in the healthcare field can contribute to recruiting heterogeneous medical devices and creating smart cooperation between them. This cooperation leads to an increase in the efficiency of the entire medical system, thus accelerating the diagnosis and curing of patients, in general, and rescuing critical cases in particular. In this paper, a large-scale IoT-enabled healthcare architecture is proposed. To achieve a wide range of communication between healthcare devices, not only are Internet coverage tools utilized but also satellites and high-altitude platforms (HAPs). In addition, the clustering idea is applied in the proposed architecture to facilitate its management. Moreover, healthcare data are prioritized into several levels of importance. Finally, NS3 is used to measure the performance of the proposed IoT-enabled healthcare architecture. The performance metrics are delay, energy consumption, packet loss, coverage tool usage, throughput, percentage of served users, and percentage of each exchanged data type. The simulation results demonstrate that the proposed IoT-enabled healthcare architecture outperforms the traditional healthcare architecture.


2019 ◽  
Vol 9 (10) ◽  
pp. 2003 ◽  
Author(s):  
Tung-Ming Pan ◽  
Kuo-Chin Fan ◽  
Yuan-Kai Wang

Intelligent analysis of surveillance videos over networks requires high recognition accuracy by analyzing good-quality videos that however introduce significant bandwidth requirement. Degraded video quality because of high object dynamics under wireless video transmission induces more critical issues to the success of smart video surveillance. In this paper, an object-based source coding method is proposed to preserve constant quality of video streaming over wireless networks. The inverse relationship between video quality and object dynamics (i.e., decreasing video quality due to the occurrence of large and fast-moving objects) is characterized statistically as a linear model. A regression algorithm that uses robust M-estimator statistics is proposed to construct the linear model with respect to different bitrates. The linear model is applied to predict the bitrate increment required to enhance video quality. A simulated wireless environment is set up to verify the proposed method under different wireless situations. Experiments with real surveillance videos of a variety of object dynamics are conducted to evaluate the performance of the method. Experimental results demonstrate significant improvement of streaming videos relative to both visual and quantitative aspects.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manop Yingram ◽  
Suttichai Premrudeepreechacharn

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initiate an undervoltage shift (active method), which changes the undervoltage shift of inverter, when the passive method cannot have a clear discrimination between islanding and other events in the system. Simulation results on MATLAB/SIMULINK show that over/undervoltage and undervoltage shifts of hybrid islanding detection method are very effective because they can determine anti-islanding condition very fast.ΔP/P>38.41% could determine anti-islanding condition within 0.04 s;ΔP/P<-24.39% could determine anti-islanding condition within 0.04 s;-24.39%≤ΔP/P≤ 38.41% could determine anti-islanding condition within 0.08 s. This method perturbed the system, only in the case of-24.39% ≤ΔP/P ≤38.41% at which the control system of inverter injected a signal of undervoltage shift as necessary to check if the occurrence condition was an islanding condition or not.


2014 ◽  
Vol 953-954 ◽  
pp. 66-73
Author(s):  
Yan Ling Liu ◽  
Xue Zeng Shi ◽  
Yuan Yu

This paper presents the design of a solar/gas driving double effect LiBr-H2O absorption system. In order to use solar energy more efficiently, a new kind of solar/gas driving double effect LiBr-H2O absorption system is designed. In this system, the high-pressure generator is driven by conventional energy, natural gas, and solar energy together with water vapor generated in the high-pressure generator, which supplies energy to the low-pressure generator for a double effect absorption system. Simulation results illustrate that this kind of system is feasible and economical. Economic evaluation of several systems is also given in this paper in order to get a clear knowledge of the energy consumption of the system.


2012 ◽  
Vol 532-533 ◽  
pp. 1219-1224
Author(s):  
Hong Tao Deng

During video transmission over error prone network, compressed video bit-stream is sensitive to channel errors that may degrade the decoded pictures severely. In order to solve this problem, error concealment technique is a useful post-processing tool for recovering the lost information. In these methods, how to estimate the lost motion vector correctly is important for the quality of decoded picture. In order to recover the lost motion vector, an Decoder Motion Vector Estimation (DMVE) criterion was proposed and have well effect for recover the lost blocks. In this paper, we propose an improved error concealment method based on DMVE, which exploits the accurate motion vector by using redundant motion vector information. The experimental results with an H.264 codec show that our method improves both subjective and objective decoder reconstructed video quality, especially for sequences of drastic motion.


2013 ◽  
Vol 310 ◽  
pp. 236-239 ◽  
Author(s):  
Zhi Chao Zhou ◽  
Xiao Ling Chen ◽  
Yuan Zou

According to the power performance index of the bulldozer, the matching calculation of electric drive tracked bulldozer transmission system is put forward, including AC induction motor, reduction ratios between motors and sprockets, engine-generator. Combined with the slip rate simulation of the special operation cycle conditions of bulldozer eletromechanical transmission system based on Matlab/Simulink is performed. Simulation results show that the dynamic characteristic satisfy the requirements of the job performance of the bulldozer. The matching calculation of the eletromechanical transmission system for bulldozer proved itself to be effective and feasible.


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