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In this paper, we propose a new error concealment algorithm for video/image based on canonical correlation analysis (CCA). Motivated by the Intra prediction in H.264/AVC, it is reasonable to assume that there is a strong spatial correlation relationship between the lost regions and their known adjacent regions. Based on the above idea, we use CCA to estimate a correlation projection matrix which utilizes...
In recent years, many SDR base band processors have been proposed to meet the high performance and programmability requirement for emerging wireless communications. To be able to support hundreds of Mbps or even Gbps wireless communications, such SDR base band processors often have massive parallel computation capability. This promising processing capability may also be exploited for other types of...
Spatial resolution reduction of compressed video is highly desirable in video transcoding. Many studies have addressed this problem, but they either cause drift error or have high computation complexity. A new spatial downsampling algorithm for DCT-Domain video transcoder is proposed in this paper, in which L??M sub-blocks of N??N are combined into a L??N rows and M??N columns blocks in DCT-Domain...
This paper develops a new error concealment algorithm for the whole-frame losses in wireless video transmission based on H.264/AVC. At first, we propose a forward motion vector extrapolation algorithm based on variable-size block motion vector estimation to obtain the motion vector field of the loss frame without yielding the hole problems. Then, we partition the missing frame into several object...
In this thesis, in the foundation of overview the present research situation of encryption algorithm, research on the concrete realization of MPEG video encryption algorithm and the transplantation of DM642, the main research contents are as follows: in simplifies to MPEG-4 VISUAL XviD source code, in the foundation of which we design and implement the representative VEA algorithm and the entropy...
Multimedia applications have become the most promising applications over wireless networks. However,wireless networks have lower bandwidth than wired networks, this calls for fast bitrate reduction techniques through video transcoding that can deliver the best video quality to the receiver while adhering to the bitrate constraints of the wireless network.This paper presents a hybrid homogenous H.264...
Wireless video transmission is expected to experience entire frame losses since data packets always carry a whole frame in low bitrate coding scenario. In this paper, we propose an entire frame loss recovery algorithm for H.264/AVC by using variable-size block motion vector extrapolation. At first, the proposed algorithm extrapolates MVs from available previous frames onto the lost frame and determines...
Wireless video communication is an important application supported by 3G mobile communication systems. Motivated by the wide adoption of H.264 and the demand of universal multimedia data access over wireless network, this paper presents a fast video transcoder, working entirely in the DCT-domain, to convert high quality H.264 bitstream into low bit rate stream with low spatial resolution for wireless...
Motivated by the wide adoption of H.264 and the demand of universal multimedia data access over wireless network , this paper studies H.264 homogeneous video transcoding with spatial resolution conversion. Firstly , we propose a fast video transcoder ,working entirely in the DCT-domain,to convert high quality H.264 bitstream into low bit rate stream with low spatial resolution for wireless video access...
In this paper, we develop a whole frame loss recovery method for H.264 by using block-based motion vector extrapolation in the decoder. Firstly,we propose a variable-size block motion vector extrapolation algorithm to construct the motion vectors for the lost frame from available neighboring frame. Then, a more complete motion vector field is obtained by performing median filtering. At last, the blocks...
This paper presents a hybrid H.264 video transcoding scheme in order to reduce the bitrate. Firstly, we propose a cascaded pixel-domain architecture to transcode intra frame which can enhance the rate-distortion performance; Then, we propose to transcode inter frame with open-loop architecture, which can improve the transcoding speed; at last, we propose a drift error compensation algorithm for P...
In this paper, we develop an improved error concealment scheme for entire frame loss of H.264/AVC by using variable-size block motion vector extrapolation. At first, the proposed algorithm extrapolates MVs from available neighboring frames onto the lost frame and determines the MV of each 8times8 block, for those blocks with dissimilar candidate MVs, they are divided into four sub-blocks and an re-estimation...
Under limited channel capacity condition, this study investigates a combined source and channel coding algorithm providing a uniform video transmission rate to achieve better system performance in wireless MIMO systems. In the proposed algorithm, we applied MPEG2 video source coding scheme with convolutional channel coding as well as space-time block coding techniques, associated with BPSK/QPSK modulation...
The article analyzes the advantage and disadvantage of part lacking fidelity searching algorithm, based on early ending technology thought. Given the disadvantage of the partial distortion search (PDS) algorithm, it brings up one kind of improved method which is similar to it. The improved algorithm also calculates sum of absolute difference (SAD) once within a row and add it to the block pixel SAD,...
A low-complexity and very low bitrate scalable video coding scheme is proposed in this paper. The proposed scheme consists of a novel weighted smoothing method and a novel interpolation mode map method to efficiently interpolate motion vectors between layers. The weighted smoothing method gives smoother motion vector field by considering the motion boundaries through motion vector correlation. In...
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