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Supavadee Aramvith - One of the best experts on this subject based on the ideXlab platform.
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an error resilience technique based on fmo and error propagation for h 264 video coding in error prone channels
International Conference on Multimedia and Expo, 2009Co-Authors: Tien Huu Vu, Supavadee AramvithAbstract:Flexible Macroblock Ordering (FMO) is one of the new error resilience techniques in H.264 that can be used to mitigate the effects of error in error prone environments. Using FMO, each Macroblock can be assigned independently to a certain slice group by using a Macroblock allocation map (MBAmap). FMO tool depends on how the Macroblocks are ordered, and various methods of reducing the error during MBAmap creation have been proposed. However, these methods usually focused on how to reduce the effects of error Macroblocks within a frame while the issue of error propagation between frames has not been considered. This study concentrates on estimating the effects caused by the damaged Macroblocks of the current frame to the next frame and the other Macroblocks in the same slice group. These effects can be used in the evaluation of the Macroblocks' importance in the current frame, and a suitable map with a reduced effect of error propagation can be generated. Results show that this method has improvements in PSNR and the number of undecodable Macroblocks when compared to the other methods that did not take the effects of inter-frame error propagation into consideration.
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ICME - An error resilience technique based on FMO and error propagation for H.264 video coding in error-prone channels
2009 IEEE International Conference on Multimedia and Expo, 2009Co-Authors: Tien Huu Vu, Supavadee AramvithAbstract:Flexible Macroblock Ordering (FMO) is one of the new error resilience techniques in H.264 that can be used to mitigate the effects of error in error prone environments. Using FMO, each Macroblock can be assigned independently to a certain slice group by using a Macroblock allocation map (MBAmap). FMO tool depends on how the Macroblocks are ordered, and various methods of reducing the error during MBAmap creation have been proposed. However, these methods usually focused on how to reduce the effects of error Macroblocks within a frame while the issue of error propagation between frames has not been considered. This study concentrates on estimating the effects caused by the damaged Macroblocks of the current frame to the next frame and the other Macroblocks in the same slice group. These effects can be used in the evaluation of the Macroblocks' importance in the current frame, and a suitable map with a reduced effect of error propagation can be generated. Results show that this method has improvements in PSNR and the number of undecodable Macroblocks when compared to the other methods that did not take the effects of inter-frame error propagation into consideration.
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Improved Sorting Algorithm for Explicit FMO Macroblock Classification in H.264
2008 International Symposium on Communications and Information Technologies, 2008Co-Authors: Rhandley D. Cajote, Supavadee Aramvith, Rowena Cristina L. Guevara, Yoshikazu MiyanagaAbstract:An improved sorting algorithm is presented that classifies Macroblocks into different slice groups for FMO in H.264. The classification process reinforces the slice structured coding nature of H.264 by making a conscious effort to minimize the variations in the statistics of the Macroblock parameters of the resulting slice group maps. Results show that modest improvements can be achieved in terms of PSNR and the number of undecodable Macroblocks by using the proposed improved sorting algorithm as compared to an interleave sorting algorithm where the MB is assigned to different slice groups following the order of the sorted list.
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Joint Flexible Macroblock Ordering and FEC Coding for H.264 Wireless Video Transmission
2006 International Symposium on Intelligent Signal Processing and Communications, 2006Co-Authors: Supavadee Aramvith, Wisut HantanongAbstract:"Flexible Macroblock Ordering" is the Macroblock-level error resilience tool defined in H.264 video coding standard for wireless video transmission. Nevertheless the issue of how to suitably arrange the Macroblock in suitable mapping is yet to clarified and investigated. This paper addresses this issue and proposes the use of the encoder's Macroblock coded-bit-count information as an indicator for a choice of Macroblock-address-map of each picture. This proposed mapping is jointly used with forward error correction (FEC) coding. Simulation results under the scenarios of slow and fast fading channels verify the proposed technique help reduce the number of undecodable Macroblocks of up to 86%. The works would improve the effectiveness of wireless video transmission.
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Joint Flexible Macroblock Ordering andFECCodingforH.264Wireless VideoTransmission
2006Co-Authors: Supavadee AramvithAbstract:Flexible Macroblock Ordering" istheMacroblock- effectiveness ofusingpredefined mappingandexplicit level errorresilience tooldefined inH.264videocodingmappinginslowandfast fading wireless channel condition. standard forwireless video transmission. Nevertheless the We propose tousetheMacroblock bit-count information asa issue ofhowtosuitably arrange theMacroblock insuitablemeantoindicate a choiceofFMO Macroblock-to-slice mapping isyettoclarified andinvestigated. Thispaper Allocation map(MBAmap)ofeachpicture andintegrate this addresses this issue andproposes theuseoftheencoder'sschemewithFEC codingto reducethenumberof Macroblock coded-bit-count information asanindicator fora undecodable Macroblock. choice ofMacroblock-address-map ofeachpicture. This proposed mappingisjointly usedwithforward error Thispaperisorganized asfollows. Analysis ofFMO on correction (FEC)coding. Simulation results underthe videoquality underwireless channel errors ispresented in scenarios ofslowandfast fading channels verify theproposedpartII.PartIIIdescribes theproposed Macroblock-to-slice technique helpreducethe numberof undecodablegroupmapping using bit-count information andFECcoding. Macroblocks ofupto86%.Theworkswouldimprovethe Inpart IV,thesimulation results arediscussed. Conclusions effectiveness ofwireless video transmission. andfuture works aregiven inpart V.
Lappui Chau - One of the best experts on this subject based on the ideXlab platform.
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Error-resilient coding of H.264 based on periodic Macroblock
IEEE Transactions on Broadcasting, 2006Co-Authors: Jinghong Zheng, Lappui ChauAbstract:For the compressed video, since an inter-frame depends on the previously encoded frame, the error in one inter-frame may propagate to the following inter-frames. In this paper, we present a new error-resilient coding scheme to alleviate the effect of error propagation for the new coding standard H.264. In this new coding standard, multiple reference frame is adopted to improve the coding efficiency. By making use of the reference frame buffer in the encoder, we can reference some Macroblocks in every n/sup th/ inter-frame to the frame that is n frames interval away, and these Macroblocks are named as periodic Macroblocks. The periodic Macroblock can efficiently alleviate the error propagation between two frames that contain periodic Macroblocks. We prove it in theory that encoding selected periodic Macroblocks will reduce the loss probability of pixel. The selection of periodic Macroblock is based on the distortion expectation of each Macroblock in every n/sup th/ frame. The number of periodic Macroblocks in every n/sup th/ frame can be adjusted according to the available transmission bandwidth, as the periodic Macroblock will consume little more bits. The simulation results prove that the periodic Macroblocks can obviously improve the quality of video at different Macroblock loss rates. When the Macroblock lost rate is 15% in every frame, the PSNR of video sequence can be improved about 3dB with 5% bitrate increase.
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efficient motion vector recovery algorithm for h 264 based on a polynomial model
IEEE Transactions on Multimedia, 2005Co-Authors: Jinghong Zheng, Lappui ChauAbstract:In this paper, we propose an efficient motion vector recovery algorithm for the new coding standard H.264, which is based on a polynomial model. To achieve better coding efficiency, the motion estimation scheme used in H.264 is different from previous coding standards. In H.264, a 16/spl times/16 Macroblock can be divided into different block shapes for motion estimation. Each Macroblock contains more motion vectors than previous coding standards. For nature video, the blocks within a small area likely belong to the same object, hence the motion vectors of neighboring blocks are highly correlated. Based on the correlation of neighboring motion vectors, we can use the motion vectors that are adjacent to the lost motion vectors to constitute a polynomial model, which can describe the change tendency of motion vectors within a small area. Through this model, the lost motion vectors can be predicted and the lost Macroblocks can be reconstructed. Different video sequences are used to test the performance of proposed method. The simulation results show that the quality of corrupted video can be obviously improved by proposed algorithm.
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Error-concealment algorithm for H.26L using first-order plane estimation
IEEE Transactions on Multimedia, 2004Co-Authors: Jinghong Zheng, Lappui ChauAbstract:In this paper, we propose a new error-concealment algorithm for the forthcoming video coding standard H.26L, which makes use of a first-order plane to estimate motion vectors. In H.26L, a 16/spl times/16 inter macroblok can be divided into variant block shape for motion prediction, and there are up to sixteen sets of motion vector in one Macroblock. For nature image, the motions within a small area are likely to move in the same direction. By using the motion vectors that are next to the vertices of lost Macroblock, we can constitute a first-order plane that indicates the movement tendency in this small area, and estimate the motion vector of vertices. Then we use the motion vectors of vertices to interpolate motion vector for each pixel separately. The interpolation function we selected makes the motion change smoothly within the lost Macroblock. The simulation results show that our method can efficiently improve the video quality over different Macroblock lost rate.
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ICIP - Content-based periodic Macroblock for error-resilient transmission of H.264 video
2004 International Conference on Image Processing 2004. ICIP '04., 1Co-Authors: Jinghong Zheng, Lappui ChauAbstract:For the compressed video, the transmission error in one frame will propagate to the following frames and the qualities of successive frames will drop seriously. In this paper, we present a new error-resilience scheme to alleviate the effect of error propagation in video transmission for the new coding standard H.264. In this new coding standard, multiple reference frame is adopted to achieve better coding efficiency than previous coding standard. By making use of the reference frame buffer in encoder, we can make some Macroblocks in every p inter frame to reference the frame that is p frames interval away and these Macroblocks are named as periodic Macroblocks. The periodic Macroblock can efficiently alleviate the error propagation between the frames that contain periodic Macroblocks. The selection of periodic Macroblock is based on the distortion expectation of each Macroblock in every p frame. The number of periodic Macroblock in every p frame can be determined by the transmission bandwidth, as the periodic Macroblock will consume a little more bits. The simulation results prove that the periodic Macroblocks can obviously improve the quality of video with different Macroblock loss rate.
Wan-chi Siu - One of the best experts on this subject based on the ideXlab platform.
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Y.; Siu W.; “Priority Search Technique for MPEG-4 Motion Estimation of Arbitrarily Shaped Video Object
2016Co-Authors: Ko-cheung Hui, Yui-lam Chan, Wan-chi SiuAbstract:One of the main differences between the MPEG-4 video and the previously standardized video coding schemes is the support of arbitrarily shaped video objects, for which most of the existing fast motion estimation algorithms are not suitable. The conventional fast motion estimation algorithm works well for opaque Macroblocks, but not the case for a boundary Macroblock which contains a large number of local minima on its error surface. In this paper, we propose a fast search algorithm which incorporates the binary alpha-plane to predict accurately the motion vectors of boundary Macroblocks. Besides, these accurate motion vectors can be used to develop a novel priority search algorithm which is an efficient search strategy for the remaining opaque Macroblocks. Experimental results show that, when compared to the conventional methods, our approach requires a low computational complexity and provides a significant improvement in terms of accuracy in motion-compensated video object planes. 1
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Macroblock-Based Algorithm for Dual-Bitstream MPEG Video Streaming with VCR Functionalities
2016Co-Authors: Yui-lam Chan, Wan-chi SiuAbstract:Abstract — Reverse playback is the most common video cassette recording (VCR) functions in many digital video players. How-ever, the predictive processing techniques employed in MPEG severely complicate the reverse-play operation. One approach to achieve the reverse playback is to store an additional backward-encoded bitstream into the server. Once the client requests a backward-play operation, the server will select an appropriate frame for the client from either the forward or backward-encoded bitstream by considering the cost of network bandwidth and the decoder complexity. Unfortunately, the forward and backward-encoded bistreams are encoded separately. The frame that has previously decoded by the client may not exactly identical to the reference of the current selected frame and the drift problem is occurred. In this paper, we propose a Macroblock-based approach to alleviate the drift problem with the minimal requirements on the network bandwidth and the decoder complexity. The novel Macroblock-based techniques are used to manipulate the necessary Macroblocks in the compressed-domain and the server then sends the processed Macroblocks to the client machine. Experimental results show that, as compared to the conventional dual-bitstream system, the new streaming system enhances the quality of the reconstructed frame significantly. I
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Reverse-Play Algorithm for MPEG Video Streaming
2016Co-Authors: Yui-lam Chan, Wan-chi SiuAbstract:Reverse playback involves playing back video frames in reverse order. However, it is not a straightforward task in MPEG digital video due to the use of predictive processing techniques in MPEG. In this paper, we propose a compressed-domain approach for the efficient implementation of an MPEG video streaming system to provide the reverse-play operation over a network. In the proposed video streaming server, a novel Macroblock-based algorithm is used to adaptively select the necessary Macroblocks, manipulate them in compressed-domain and send the processed Macroblocks to the client machine. Besides, we propose a technique of mismatch error compensation such that there is only a negligibly small PSNR degradation during reverse playback of the proposed algorithm. Experimental results show that, as compared to the conventional system, the new streaming system reduces the required network bandwidth and the decoder complexity significantly in reverse playback. Index Terms: Compressed-domain processing, digital vide
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On re-composition of motion compensated Macroblocks for DCT-based video transcoding
Signal Processing: Image Communication, 2006Co-Authors: Kai-tat Fung, Wan-chi SiuAbstract:To achieve portability between different kinds of encoding formats and network environments, heterogeneous video transcoding becomes a key technique for reducing the bitrate of a previously compressed video signal. A frame-skipping transcoder is often used to avoid an unacceptable picture quality when high transcoding ratio is required. Due to high computational complexity and quality degradation introduced by conventional frame-skipping transcoders, a DCT-based video frame-skipping transcoder has been proposed recently. However, the transcoding process of the motion compensated Macroblocks in the DCT domain becomes the bottleneck since IDCT and DCT processes are required. In this paper, we propose a new architecture of the frame-skipping transcoder to reduce the computational complexity of motion compensated Macroblocks in the frame-skipping process. The new architecture transcodes the dominant region of a motion compensated Macroblock in the DCT domain by making use of the DCT coefficients of the incoming bistream and some pre-computed shift operators. By using a shifted version of the dominant vector, the re-encoding error introduced in the dominant region can be avoided. On the other hand, an adaptive transcoding architecture to transcode the boundary regions of MC marcoblocks and a way to perform error compensation are proposed. This architecture can further speed up the transcoding process of the motion compensated Macroblocks. Half pixel accuracy related to our proposed frame skipping transcoder is also addressed. Experimental results show that, as compared to the conventional or DCT-based transocders, the new architecture is more robust to noise, gives rise to fewer requantization errors, and requires simple computational complexity.
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ICIP - Improved Macroblock-based reverse play algorithm for MPEG video streaming
2004 International Conference on Image Processing 2004. ICIP '04., 1Co-Authors: Yui-lam Chan, Wan-chi SiuAbstract:Reverse playback is the most common video cassette recording (VCR) functions in many digital video players. However, the predictive processing techniques employed in MPEG severely complicate the reverse-play operation. In this paper, we enhance our previously proposed compressed-domain approach for the efficient reverse-play operation of an MPEG video streaming system. In the proposed video streaming server, a novel Macroblock-based algorithm is used to adaptively select the necessary Macroblocks, manipulate the Macroblocks and send the processed Macroblocks to the client machine. The proposed approach only manipulates Macroblocks either on the VLC-domain or DCT-domain to achieve the server with low complexity. Experimental results show that, as compared to the conventional system and the previously proposed compressed-domain system, the new streaming system reduces the required network bandwidth and the decoding complexity significantly.
Jinghong Zheng - One of the best experts on this subject based on the ideXlab platform.
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Error-resilient coding of H.264 based on periodic Macroblock
IEEE Transactions on Broadcasting, 2006Co-Authors: Jinghong Zheng, Lappui ChauAbstract:For the compressed video, since an inter-frame depends on the previously encoded frame, the error in one inter-frame may propagate to the following inter-frames. In this paper, we present a new error-resilient coding scheme to alleviate the effect of error propagation for the new coding standard H.264. In this new coding standard, multiple reference frame is adopted to improve the coding efficiency. By making use of the reference frame buffer in the encoder, we can reference some Macroblocks in every n/sup th/ inter-frame to the frame that is n frames interval away, and these Macroblocks are named as periodic Macroblocks. The periodic Macroblock can efficiently alleviate the error propagation between two frames that contain periodic Macroblocks. We prove it in theory that encoding selected periodic Macroblocks will reduce the loss probability of pixel. The selection of periodic Macroblock is based on the distortion expectation of each Macroblock in every n/sup th/ frame. The number of periodic Macroblocks in every n/sup th/ frame can be adjusted according to the available transmission bandwidth, as the periodic Macroblock will consume little more bits. The simulation results prove that the periodic Macroblocks can obviously improve the quality of video at different Macroblock loss rates. When the Macroblock lost rate is 15% in every frame, the PSNR of video sequence can be improved about 3dB with 5% bitrate increase.
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efficient motion vector recovery algorithm for h 264 based on a polynomial model
IEEE Transactions on Multimedia, 2005Co-Authors: Jinghong Zheng, Lappui ChauAbstract:In this paper, we propose an efficient motion vector recovery algorithm for the new coding standard H.264, which is based on a polynomial model. To achieve better coding efficiency, the motion estimation scheme used in H.264 is different from previous coding standards. In H.264, a 16/spl times/16 Macroblock can be divided into different block shapes for motion estimation. Each Macroblock contains more motion vectors than previous coding standards. For nature video, the blocks within a small area likely belong to the same object, hence the motion vectors of neighboring blocks are highly correlated. Based on the correlation of neighboring motion vectors, we can use the motion vectors that are adjacent to the lost motion vectors to constitute a polynomial model, which can describe the change tendency of motion vectors within a small area. Through this model, the lost motion vectors can be predicted and the lost Macroblocks can be reconstructed. Different video sequences are used to test the performance of proposed method. The simulation results show that the quality of corrupted video can be obviously improved by proposed algorithm.
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Error-concealment algorithm for H.26L using first-order plane estimation
IEEE Transactions on Multimedia, 2004Co-Authors: Jinghong Zheng, Lappui ChauAbstract:In this paper, we propose a new error-concealment algorithm for the forthcoming video coding standard H.26L, which makes use of a first-order plane to estimate motion vectors. In H.26L, a 16/spl times/16 inter macroblok can be divided into variant block shape for motion prediction, and there are up to sixteen sets of motion vector in one Macroblock. For nature image, the motions within a small area are likely to move in the same direction. By using the motion vectors that are next to the vertices of lost Macroblock, we can constitute a first-order plane that indicates the movement tendency in this small area, and estimate the motion vector of vertices. Then we use the motion vectors of vertices to interpolate motion vector for each pixel separately. The interpolation function we selected makes the motion change smoothly within the lost Macroblock. The simulation results show that our method can efficiently improve the video quality over different Macroblock lost rate.
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ICIP - Content-based periodic Macroblock for error-resilient transmission of H.264 video
2004 International Conference on Image Processing 2004. ICIP '04., 1Co-Authors: Jinghong Zheng, Lappui ChauAbstract:For the compressed video, the transmission error in one frame will propagate to the following frames and the qualities of successive frames will drop seriously. In this paper, we present a new error-resilience scheme to alleviate the effect of error propagation in video transmission for the new coding standard H.264. In this new coding standard, multiple reference frame is adopted to achieve better coding efficiency than previous coding standard. By making use of the reference frame buffer in encoder, we can make some Macroblocks in every p inter frame to reference the frame that is p frames interval away and these Macroblocks are named as periodic Macroblocks. The periodic Macroblock can efficiently alleviate the error propagation between the frames that contain periodic Macroblocks. The selection of periodic Macroblock is based on the distortion expectation of each Macroblock in every p frame. The number of periodic Macroblock in every p frame can be determined by the transmission bandwidth, as the periodic Macroblock will consume a little more bits. The simulation results prove that the periodic Macroblocks can obviously improve the quality of video with different Macroblock loss rate.
Liu Jian-dong - One of the best experts on this subject based on the ideXlab platform.
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Temporal Error Concealment Algorithm Based on Macroblock Mode Prediction
Computer Engineering, 2009Co-Authors: Liu Jian-dongAbstract:Aiming at the problem that the compressed video stream will inevitable be corrupted because of the wireless channel errors,which may degrade the reconstructed image quality,this paper presents an efficient temporal error concealment method which based on improved border-matching function and flexible Macroblock mode of H.264 video standard. It utilizes the relativity between lost Macroblock and other surrounding Macroblocks to predict the block mode,and estimates the motion vector of the lost Macroblock depending on the block mode. Simulation results under 3GPP/3GPP2 wireless channel show the proposed method performs better quality than other approaches with the same RTP packet loss rate.
