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In this work we study adaptive resource allocation for uplink transmission of correlated video sources. We consider a framework where multiple wireless sources transmit correlated information via a common base station. We introduce an optimization problem for sources to maximize the weighted sum of received quality of all videos, when source correlation can be used at the decoder in case of missing...
In this paper, for the generation of drift-error-resilient coded bitstreams at the encoder side, an investigation on the drift-error propagation in H.264 by applying different motion estimation precisions is carried out. The results show that the drift-error propagation in half-pixel motion estimation precision increases due to the usage of six-tap filter. Mathematical model for estimating drift-error...
H.264/AVC is a powerful and high performance video compression standard. To achieve high coding efficiency, it employs many new techniques, such as spatial prediction in intra coding, adaptive block size inter coding and motion compensation, multiple reference pictures, and so on. Especially the complex intra and inter encoding modes, obtain notable coding gains. The high computation burden of mode...
This paper presents a simple but effective macroblock (MB) layer rate control (RC) scheme for H.264/AVC with low complexity. First, to reduce computation cost and inaccuracy of linear mean absolute difference (MAD) prediction at MB layer adopted in JVT-G012, MAD is computed directly according to the difference between current original MB and the reference blocks pointed by estimated MV using intensive...
The scalable video coding (SVC) standard adopts the variable size motion estimation (ME) to select the best coding mode for each macroblock (MB). Although this technique achieves the highest possible coding efficiency, it results in extremely large computation complexity which obstructs SVC from the practical application. In this paper, we propose an adaptive early termination of fast mode decision...
In this paper, we present 2-D direction-adaptive transforms for coding prediction residuals of video. These Direction-Adaptive Residual Transforms (DART) are shown to be more effective than the traditional 2-D DCT when coding residual blocks that contain directional features. After presenting the directional transform structures and improvements to their efficiency, we outline how they are used to...
In the macroblock coding mode selection process, to improve the judging speed of intra macroblock refresh, the codec usually uses the previous frame temporal information and low-level SVC layer image information to prejudge to reduce the range of candidate macroblock coding modes. As the compressed bitstreams are particular sensitive to error, in order to enhance the error resilience of compressed...
In this paper, we propose a fast algorithm designed for the hierarchical prediction structure in H.264/MPEG scalable video coding (SVC). It can efficiently reduce the heavy computational burden in performing the bi-directional (BI) prediction. We carefully examine the correlation of motion-rate costs and distortion values between BI and FW (forward) and BW (backward) prediction types. Then we construct...
A new intra-frame coding scheme is proposed for progressive video sequences in H.264/AVC. In the proposed method, every other pixel is sampled either in a horizontal or vertical direction without any anti-aliasing filtering, and two sub-frames of the even-pixel and odd-pixel are then generated. The even-pixel and odd-pixel sub-frames are coded by the intra-and inter-frame coding methods, respectively...
Distributed multi-view video coding (DMVC) has become a focus due to the prosperity of the multimedia applications in wireless sensor networks. We propose a novel method of an adaptive scheme, named side-information-adaptive Low Density Parity Check (LDPC) coding. Apart from the existing multiple side-information implications in DMVC, this paper is dedicated to not only utilizing LDPC to produce the...
H.264/AVC is the latest video coding standard from ITU-T. It provides superior and efficient video coding at low bit rates. Flexible macroblocks ordering (FMO) is an error-resilient tool included in H.264/AVC. In this paper, a novel technique for adaptive classification of macroblocks into two slice groups using FMO method is proposed. With our adaptive macroblocks allocation map, simulation results...
We propose a new method for improving motion vector coding. The coding efficiency of the H.264/AVC standard is significantly degraded for video sequences that include irregular motions. The degradation is caused by the fact that the correlations among the motion vectors on adjacent blocks get to be small when motions are irregular. Our method solves this problem by two schemes. First, the predictive...
We propose a distributed source coding system for data collected by sensor networks. It uses a feedback channel between the sensors and the gateway node (i.e., the joint decoder) but, unlike previous systems, the encoding process is driven by the decoder. Compression is performed using distributed arithmetic coding, which is extended to adaptively estimate the source probabilities. Specifically, the...
The recent H.264 video coding standard adopted context-based adaptive variable length coding (CAVLC) as the entropy coding tool. By combining adaptive variable length coding (VLC) with context modeling, we can achieve a high degree of redundancy reduction. However, CAVLC in H.264 has a problem that correctness of VLC table prediction is low. In this paper, we propose a new VLC table prediction algorithm...
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