In this paper, low-complexity error-resilience and error-concealment methods for the scalable video coding （SVC） extension of H.264/AVC are described. At the encoder, multiple-description coding （MDC） is used as e...In this paper, low-complexity error-resilience and error-concealment methods for the scalable video coding （SVC） extension of H.264/AVC are described. At the encoder, multiple-description coding （MDC） is used as error-resilient coding. Balanced scalable multiple descriptions are generated by mixing the pre-encoded scalable bit streams. Each description is wholly decodable using a standard SVC decoder. A preprocessor can be placed before an SVC decoder to extract the packets from the highest-quality bit stream. At the decoder, error concealment involves using a lightweight decoder preprocessor to generate a valid bit stream from the available network abstraction layer （NAL） units when medium-grain scalability （MGS） layers are used. Modifications are made to the NAL unit header or slice header if some NAL units of MGS layers are lost. The number of additional packets that a decoder discards as a result of a packet loss is minimized. The proposed error-resilience and error-concealment methods require little computation, which makes them suitable for real-time video streaming. Experiment results show that the proposed methods significantly reduce quality degradation caused by packet loss.展开更多
One of the most interesting questions of video streaming over the Intemet is packet loss. Some error resilient technologies have been proposed to overcome quality decrease of reconsixucted video occurred due to packet...One of the most interesting questions of video streaming over the Intemet is packet loss. Some error resilient technologies have been proposed to overcome quality decrease of reconsixucted video occurred due to packet loss, in which optimized reconstructionbased DCT （ORB-DCT） utilizes two-direction interleaving. An improved ORB-DCT （IORB-DCT）, which uses four-direction interleaving, is proposed in this paper. Experimental results are demonstrated to verify the effectiveness of the proposed IORB-DCT.展开更多
The video bit stream coded by H.263 recommendation is vulnerable to channel errors. For coded information, bit errors could result in error propagation, loss of synchronization and severe data loss. All of these will ...The video bit stream coded by H.263 recommendation is vulnerable to channel errors. For coded information, bit errors could result in error propagation, loss of synchronization and severe data loss. All of these will lead to the descent of image qualities in the end. In this paper, in order to solve this problem, we present a receiver based error concealment algorithm that uses information in pixel domain to detect errors and resynchronization, identify the location of the affected blocks and estimate erroneous data. The concealment algorithm is kept simple, no additional bit rate is required, and no modification is necessary to an existing encoder, so the real time decoding and concealment are possible. Computer emulation results show that the image quality after error concealment is significantly improved.展开更多
This article addresses the problem of reference picture optimization in video communication over error prone networks. A novel estimation model for transmission distortion is proposed. This model is capable of recursi...This article addresses the problem of reference picture optimization in video communication over error prone networks. A novel estimation model for transmission distortion is proposed. This model is capable of recursively estimating the overall end-to-end distortion caused by quantization, error propagation, and error concealment. Simulation results show that this model can accurately estimate channel distortion. Then, based on the distortion estimation model, a new non-feedback key-frame reference picture selection （KRPS） algorithm is developed. The optimum reference picture minimizes the transmission distortion under the rate-distortion optimization framework. Extensive experiment results demonstrate that the proposed KRPS algorithm substantially achieves more peak signal to noise ratio （PSNR） gain over traditional prediction, especially in low bit-rate transmission.展开更多
Today, designers are forced to reduce performance and increase power requirements in order to reserve larger margins that are required due to the greater variability introduced by smaller feature sizes and manufacturi...Today, designers are forced to reduce performance and increase power requirements in order to reserve larger margins that are required due to the greater variability introduced by smaller feature sizes and manufacturing variations of modern IC designs. The better-than-worst-case design can both address the variability problem and achieve higher performance/energy efficiency than the worst-case design. This paper surveys the progress to date, provides a snapshot of the most representative methods in this field, and discusses the future research directions of the better-than-worst-case design.展开更多
文摘In this paper, low-complexity error-resilience and error-concealment methods for the scalable video coding （SVC） extension of H.264/AVC are described. At the encoder, multiple-description coding （MDC） is used as error-resilient coding. Balanced scalable multiple descriptions are generated by mixing the pre-encoded scalable bit streams. Each description is wholly decodable using a standard SVC decoder. A preprocessor can be placed before an SVC decoder to extract the packets from the highest-quality bit stream. At the decoder, error concealment involves using a lightweight decoder preprocessor to generate a valid bit stream from the available network abstraction layer （NAL） units when medium-grain scalability （MGS） layers are used. Modifications are made to the NAL unit header or slice header if some NAL units of MGS layers are lost. The number of additional packets that a decoder discards as a result of a packet loss is minimized. The proposed error-resilience and error-concealment methods require little computation, which makes them suitable for real-time video streaming. Experiment results show that the proposed methods significantly reduce quality degradation caused by packet loss.
文摘One of the most interesting questions of video streaming over the Intemet is packet loss. Some error resilient technologies have been proposed to overcome quality decrease of reconsixucted video occurred due to packet loss, in which optimized reconstructionbased DCT （ORB-DCT） utilizes two-direction interleaving. An improved ORB-DCT （IORB-DCT）, which uses four-direction interleaving, is proposed in this paper. Experimental results are demonstrated to verify the effectiveness of the proposed IORB-DCT.
文摘The video bit stream coded by H.263 recommendation is vulnerable to channel errors. For coded information, bit errors could result in error propagation, loss of synchronization and severe data loss. All of these will lead to the descent of image qualities in the end. In this paper, in order to solve this problem, we present a receiver based error concealment algorithm that uses information in pixel domain to detect errors and resynchronization, identify the location of the affected blocks and estimate erroneous data. The concealment algorithm is kept simple, no additional bit rate is required, and no modification is necessary to an existing encoder, so the real time decoding and concealment are possible. Computer emulation results show that the image quality after error concealment is significantly improved.
基金supported by the National Natural Science Foundation of China (60672099)
文摘This article addresses the problem of reference picture optimization in video communication over error prone networks. A novel estimation model for transmission distortion is proposed. This model is capable of recursively estimating the overall end-to-end distortion caused by quantization, error propagation, and error concealment. Simulation results show that this model can accurately estimate channel distortion. Then, based on the distortion estimation model, a new non-feedback key-frame reference picture selection （KRPS） algorithm is developed. The optimum reference picture minimizes the transmission distortion under the rate-distortion optimization framework. Extensive experiment results demonstrate that the proposed KRPS algorithm substantially achieves more peak signal to noise ratio （PSNR） gain over traditional prediction, especially in low bit-rate transmission.
基金partially supported by the National Science Foundation of USA under Grant No.CCF-0903541
文摘Today, designers are forced to reduce performance and increase power requirements in order to reserve larger margins that are required due to the greater variability introduced by smaller feature sizes and manufacturing variations of modern IC designs. The better-than-worst-case design can both address the variability problem and achieve higher performance/energy efficiency than the worst-case design. This paper surveys the progress to date, provides a snapshot of the most representative methods in this field, and discusses the future research directions of the better-than-worst-case design.
