This paper presents an unequal error protection scheme for motion compensated video over the Internet. The forward error correction (FEC) codes are optimally assigned to different frames in group of picture (GOP) by e...
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This paper presents an unequal error protection scheme for motion compensated video over the Internet. The forward error correction (FEC) codes are optimally assigned to different frames in group of picture (GOP) by exploiting the temporal dependency among frames. To achieve optimal allocation of FEC assigned in GOP, we propose a performance criterion for the measurement of allocation, namely the expected length of error propagation (ELEP), which makes sense intuitively, as fewer frames corrupted implies better quality of reconstruction. Experiment results show the proposed scheme is robust to burst packet loss in the Internet. More importantly, graceful degradation of video quality is achieved by the proposed scheme as the packet loss probability of an Internet connection increases.
This paper presents a router based unequal error protection scheme for video over the Internet. The proposed scheme classifies the whole bitstream into two priorities according to their importance and packetizes them ...
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This paper presents a router based unequal error protection scheme for video over the Internet. The proposed scheme classifies the whole bitstream into two priorities according to their importance and packetizes them into packets with two priorities. To reduce the loss ratio of video packets with higher priority, an active queue management scheme is designed at each router to provide more chance for these packets to transmit over the Internet. Compared to an end-to-end based approach, in which some redundancy packets are generated to protect the packets with higher priority, our proposed scheme utilizes the whole bandwidth for the source coding. Therefore, the final picture quality is improved.
The juxtaposition of computation and biology opens up a new world of science and technology. Richard Feynman characterizes the young and fast-developing world of computer science as follows: "[it] is like enginee...
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The juxtaposition of computation and biology opens up a new world of science and technology. Richard Feynman characterizes the young and fast-developing world of computer science as follows: "[it] is like engineering-it is all about getting something to do something."1 Viewed from this perspective, the scope of research and development at this intersection is a vast, two-way street that computer science has to offer to biological science and biotechnology and vice versa. Computational thinking helps characterize, predict, and influence the dynamics of biological processes from molecular to cellular to organ in a way that revolutionizes our understanding of health and drug design. In turn, understanding the architecture and principles of natural biological processes and organization might require new models of computation, which could lead to robustness in the design of large-scale software and hardware systems, a hitherto elusive goal.
This paper presents a router based unequal error protection scheme for video over the Internet. The proposed scheme classifies the whole bitstream into two priorities according to their importance and packetizes them ...
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This paper presents a router based unequal error protection scheme for video over the Internet. The proposed scheme classifies the whole bitstream into two priorities according to their importance and packetizes them into packets with two priorities. To reduce the loss ratio of video packets with higher priority, an active queue management scheme is designed at each router to provide more chance for these packets to transmit over the Internet. Compared to an end-to-end based approach, in which some redundancy packets are generated to protect the packets with higher priority, our proposed scheme utilizes the whole bandwidth for the source coding. Therefore, the final picture quality is improved.
This paper presents an unequal error protection scheme for motion compensated video over the Internet. The forward error correction (FEC) codes are optimally assigned to different frames in group of picture (GOP) by e...
详细信息
This paper presents an unequal error protection scheme for motion compensated video over the Internet. The forward error correction (FEC) codes are optimally assigned to different frames in group of picture (GOP) by exploiting the temporal dependency among frames. To achieve optimal allocation of FEC assigned in GOP, we propose a performance criterion for the measurement of allocation, namely the expected length of error propagation (ELEP), which makes sense intuitively, as fewer frames corrupted implies better quality of reconstruction. Experiment results show the proposed scheme is robust to burst packet loss in the Internet. More importantly, graceful degradation of video quality is achieved by the proposed scheme as the packet loss probability of an Internet connection increases.
This paper presents a novel degressive error protection (DEP) algorithm adaptive to time varying packet loss rate for robustly transporting MPEG-4 fine granularity scalability (FGS) bit-stream over the packet erasure ...
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This paper presents a novel degressive error protection (DEP) algorithm adaptive to time varying packet loss rate for robustly transporting MPEG-4 fine granularity scalability (FGS) bit-stream over the packet erasure networks. By exploiting the embedded nature of FGS enhancement-layer bit-stream, a rate-distortion (R-D) optimization framework is developed to optimally partition the FGS enhancement-layer bit-stream into blocks and then to apply DEP to blocks by forward error correction (FEC). Experimental results show that this algorithm achieves graceful degradation of video quality in a wide range of packet loss rates.
We propose an adaptive unequal error protection scheme to help protect a video stream over the Internet. The data partition approach and the resynchronization marker are applied to generate two types of packets with d...
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We propose an adaptive unequal error protection scheme to help protect a video stream over the Internet. The data partition approach and the resynchronization marker are applied to generate two types of packets with different importance. Our scheme is very adaptive to network traffic conditions and can be easily implemented via software. With the proposed scheme, more protection is provided for the more important packets. The final quality can therefore be improved at a higher packet loss ratio.
The demand for a live video over the Internet and wireless links has grown rapidly. Therefore, it is very important to design a video compression system adaptive to variable network conditions. We propose an adaptive ...
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The demand for a live video over the Internet and wireless links has grown rapidly. Therefore, it is very important to design a video compression system adaptive to variable network conditions. We propose an adaptive rate control scheme, which can be applied to design a video compression system adaptive to the available channel bandwidth. This scheme is better than existing schemes in the sense that the coding process is adaptive to the network condition, fewer frames are skipped, and the average PSNR is usually improved.
In studying actual Web searching by the public at large, we analyzed over one million Web queries by users of the Excite search engine. We found that most people use few search terms, few modified queries, view few We...
In studying actual Web searching by the public at large, we analyzed over one million Web queries by users of the Excite search engine. We found that most people use few search terms, few modified queries, view few Web pages, and rarely use advanced search features. A small number of search terms are used with high frequency, and a great many terms are unique; the language of Web queries is distinctive. Queries about recreation and entertainment rank highest. Findings are compared to data from two other large studies of Web queries. This study provides an insight into the public practices and choices in Web searching.
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